NC-2009 EAp2: Minimum Energy Performance

  • NC EAp2 Credit Req's Diagram
  • Check updated requirements

    USGBC's membership approved an update to LEED 2009 effective April 8, 2016. The update only affects LEED 2009 projects registered on or after that date.

    Project teams will be required to earn a minimum of four points in EAc1, effectively making EAp2 more stringent. The referenced energy standard and modeling requirements are not changed. Buildings falling under the proposed change can use the same methodologies and referenced standards, but will need to earn additional points in order to achieve certification. 

    The intent of the change is to bring LEED 2009 energy requirements more up to date, as LEED 2009 continues to be the predominant LEED rating system, even though the more up-to-date LEED v4 has also become available.

    Beyond code compliance, but doable

    This prerequisite is a big one, not only because it’s required for all projects, but also because it feeds directly into EAc1: Optimize Energy Performance, where about a fifth of the total available points in LEED are at stake. Master these minimum requirements, and you can use the same compliance path as in EAp2 to earning points.

    You won’t earn the prerequisite by accident, though. Although “energy efficiency” is on everyone’s lips, the mandatory and performance-based requirements for EAp2 go beyond code compliance in most places. That said, there is nothing to stop you from meeting the requirements with a reasonable amount of effort, and the environmental benefits as well as the operational cost savings are significant.

    Most projects start by choosing which of the three available compliance paths to follow. We’ll look at them each in turn.

    Option 1: Energy modeling

    Option 1 alone gives you access to all of the points available through EAc1, and offers the most flexibility in giving you credit for innovative designs.

    First, you need to meet the mandatory requirements of ASHRAE 90.1-2007 for all major components, including the envelope, HVAC, lighting, and domestic hot water. ASHRAE 90.1 has had some changes and new mandatory requirements since the 2004 version, which was referenced on previous LEED systems, so be sure to review the standard carefully.

    Cost of changeEnergy efficiency is an area where it behooves project teams to start early and work together to maximize savings. Playing catch-up later on can be costly.Second, you need to demonstrate a 10% savings (5% for existing buildings) for your designed building compared with a baseline case meeting the minimum requirements of ASHRAE 90.1 (or Title 24-2005, Part 6 for California projects). You do this by creating a computer model following rules described in Appendix G of ASHRAE 90.1.

    Computer modeling offers the following key advantages:

    • It can be used to provide feedback on your design both early on, and as the design progresses, so it’s best to use in this way rather than simply demonstrating compliance.
    • It can help your team focus on the most cost-effective efficiency strategies, by plugging in different options and seeing the results.
    • If your building is unconventional or complex in design, an energy model is the best way to account for that.

    Your building type may not have a choice—you may have to follow this path, because both Options 2 and 3 are prescriptive compliance paths that are only available to specific building types and sizes.

    However, if your building type and size allow, and you don’t want to embark on the complex process of computer modeling, which also requires expert assistance from a modeler or from a member of the mechanical engineer’s team, the prescriptive compliance paths are a good way to earn the prerequisite simply by following a checklist.

    Solar shadingPassive design strategies such as shading to reduce solar heat gain are the most cost-effective ways to improve energy performance.Note, however, that when you get to EAc1, there are a lot fewer points on the table for the prescriptive paths, and that you have to follow each prescriptive requirement. These paths also require more collaboration and focus early on in design than you might think. The design team must work together to integrate all of the prescriptive requirements, and Option 3 even requires documentation of certain design processes.

    Option 2: ASHRAE Advanced Energy Design Guides

    The Advanced Energy Design Guides are published by ASHRAE for office, warehouse, and retail projects less than 20,000 ft2—so if you don’t fall into one of those categories, you’re not eligible for this path.

    These guides outline strategies to reduce energy use by 30% from 2001 levels, or an amount equivalent to approximately 10%–14% reduction from ASHRAE 90.1-2007. If you choose this compliance path, become familiar with the list of prescriptive requirements and commit to meeting all of them.

    Option 3: Advanced Buildings Core Performance Guide

    The Core Performance Guide path is a good option if all of the following are true:

    • your project is smaller than 100,000 ft2,
    • you cannot pursue Option 2 because there is not an ASHRAE guide for the building type,
    • your project is not a healthcare facility, lab, or warehouse,
    • and you would rather not commit to the energy modeling required for Option 1.

    Comply with all requirements within Sections 1 and 2 of the guide. If you choose this path, become familiar with the list of prescriptive requirements and commit to meeting them. Also note that it’s not just a list of prescriptive requirements, but a prescribed process for achieving energy efficiency goals. You must demonstrate that you considered a couple of alternate designs, for example, and that certain team meetings were held.

    Reduce energy loads first

    Energy efficiency offers a clear combination of environmental benefit and benefit to the owner through reduced operational expenses, and potentially reduced first costs, if you’re able to reduce the size and complexity of your HVAC system with a more efficient envelope.

    High-tech HVAC systems, and onsite renewable energy generation are often signature components of green buildings, but consider these strategies more “icing” on the cake, rather than a place to start. Start with building orientation and passive design features first. Also look at envelope design, such as energy-efficient windows, walls and roof, before looking at HVAC and plug loads. A poorly designed envelope with a high-tech HVAC system is not, on the whole, efficient or cost-effective. 

    District energy systems

    Projects connected to district energy systems will not be able to utilize the system efficiencies of the base plant to demonstrate compliance with the prerequisite. They can plan on benefiting from these systems under EAc1, however.

    Look for incentives

    Focusing on energy efficiency and renewable energy generation can seem to add costs to a project, but there are a variety of utility-provided, as well as state, and federal incentives available to offset those premiums. (See Resources.)

  • FAQs for EAp2

    Is it acceptable to model a split-type AC with inverter technology compressor as a heat pump, like modeling VRF?

    Ideally if the software you are using cannot model a technology directly then seek a published workaround related to your software. If you can't find a published workaround then model it as you think it should be modeled and explain how you have modeled it in the preliminary LEED submission.

    A portion of our building envelope is historic. Can we exclude it from our model?

    No, not if it is part of the LEED project. However, there is an exemption for existing building envelopes in Appendix G that allow you to model the existing condition in the baseline so you do not pay a penalty.

    For an existing building, do I need to rotate the model?

    No, not for an existing building.

    Our project has a large process load—75%. Despite our efforts to make an efficient HVAC design, the cost savings are minimal. What can we do to earn this prerequisite and be eligible for LEED certification? Is there any flexibility in how we model the process load?

    You must model accurately. Since you don't have enough savings in the building energy, find savings in the process. Either you will be able to demonstrate that compared to a conventional baseline the process being installed into the factory is demonstrably better than "similar newly constructed facilities," allowing you to claim some savings, or the owner needs to install some energy-saving measures into the process to get the project the rest of the way there. Either option can be difficult, but not impossible.

    Account for process load reductions through the exceptional calculation method. A baseline must be established based on standard practice for the process in your location. Any claim of energy savings needs a thorough narrative explaining the baseline and the strategy for energy savings along with an explanation of how the savings were calculated.

    Our process load is higher than 25%. Do we have to justify that?

    It is common to have a 80%–90% process load in a manufacturing facility. The 25% default in LEED is based on office buildings. If you think your load is lower than 25%, it is recommended that you explain why in a short narrative. It is also recommended to briefly explain it if your load is 25% exactly, since that level commonly reveals that the process loads were not accurately represented.

    Do the required savings for this prerequisite (and credit) need to come only from building energy, or also process loads?

    The energy savings are based on the whole building energy use—building and process. LEED does not stipulate exactly where they come from.

    Our local code references ASHRAE 90.1-2010. Should I use that for my documentation, or 90.1-2007?

    For LEED 2009 you'll need touse 90.1-2007. There were some significant changes in 90.1-2010—too many to account for in your LEED review, and your project would also have a much harder time demonstrating the same percentage energy savings.

    Our project doesn't have enough energy savings to earn the prerequisite. Can we get there by incorporating onsite renewables?

    Yes according to LEED, although it is not recommended as a best practice, and it is usually more cost-effective to invest in energy savings in the building.

    Can I claim exterior lighting savings for canopy lighting even though a baseline model cannot include shading elements?

    You can assume exterior lighting savings for canopies against the baseline, but not the shading effects of canopies.

    The project is built on a site with existing exterior lighting installed. How should this be accounted for?

    If exterior lighting is present on the project site, consider it as a constant in both energy model cases.

    Can mezzanines open to floors below be excluded from the energy model?

    Any conditioned area must be included in the energy model.

    How do I provide a zip code for an international location?

    The Energy Star portion of the form does not apply to international projects.

    For a project outside the U.S., how do I determine the climate zone?

    Use the tables and definitions provided in 90.1 Appendix B to determine an equivalent ASHRAE climate zone.

    For a project outside the U.S., how do I determine the Target Finder score?

    International projects are not required to enter a Target Finder score. Target Finder is based on U.S. energy use data.

    Do hotel rooms need automatic light shut-off control?

    For Section 9.4.1.1c, a manual control device would be sufficient to comply with mandatory provisions.

    How commonly are the 90.1 mandatory compliance forms submitted as part of EAp2/EAc1?

    Submitting these forms is not common; however, it can be beneficial if you are applying for any exceptions.

    The Section 9 space-by-space method does not include residential space types. What should I use?

    Use the building area method.

    Can the Passive House Planning Package (PHPP) be used to energy model for LEED?

    Although there is no formal list of approved simulation tools, there are a few requirements per G2.2.1, including the ability of the program to provide hourly simulation for 8760 hours per year, and model ten or more thermal zones, which PHPP does not meet.

    Can the Trace 700 'LEED Energy Performance Summary Report' by uploaded to LEED Online in lieu of the Section 1.4 tables spreadsheet?

    The automated Trace 700 report provides less information than is requested by the Section 1.4 tables spreadsheet. The Section 1.4 tables spreadsheet must be completed.

    Which baseline HVAC system do I use if my building has no heating or air conditioning?

    Assign HVAC systems as per Appendix-G and Section 6 but set thermostatic setpointsSetpoints are normal operating ranges for building systems and indoor environmental quality. When the building systems are outside of their normal operating range, action is taken by the building operator or automation system. out of range so that systems never turn on.

    Our project has a diesel backup generator. Should we include it in our energy model?

    If it is only used for backup and not for regular use such as peak shaving—no.

    Can SHGC be higher in the proposed than in the baseline model?

    SHGC is not a mandatory provision so it is available for trade-off and can be higher than the baseline.

    Do I need to justify the electrical and fuel rates I am using in my model?

    You generally wouldn't need to upload any documentation, but particularly for a non-U.S. project, it may help to provide a short narrative about what they are based on.

Legend

  • Best Practices
  • Gotcha
  • Action Steps
  • Cost Tip

Pre-Design

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  • Discuss your project’s energy performance objectives, along with how those are shaping design decisions, with the owner. Record energy targets in the Owners Project Requirements (OPR) for the commissioning credits EAp1 and EAc3


  • You won’t earn this prerequisite by accident. The energy efficiency requirements here are typically much more stringent than local codes, so plan on giving it special attention with your team, including leadership from the owner. 


  • Consider stating goals in terms of minimum efficiency levels and specific payback periods. For example: “Our goal is to exceed a 20% reduction from ASHRAE 90.1, with all efficiency measures having a payback period of 10 years or less.”


  • Develop a precedent for energy targets by conducting research on similar building types and using the EPA’s Target Finder program. (See Resources.)


  • For Option 1 only, you will need to comply with the mandatory requirements of ASHRAE 90.1-2007, to bring your project to the minimum level of performance. The ASHRAE 90.1-2007 User’s Manual is a great resource, with illustrated examples of solutions for meeting the requirements.


  • ASHRAE 90.1-2007 has some additional requirements compared with 2004. Read through the standard for a complete update. The following are some samples. 

    • All exterior walls must be installed with rigid insulation of the spans across all floors. This can be accomplished by placing the insulation outside the air barrier. 
    • All exterior doors must be tested for maximum air leakage rate. 
    • All spaces must have independent lighting controls. 
    • Occupancy sensors must be installed in some spaces.
    • The minimum efficiency level of specific mechanical equipment has been raised.  

  • The prerequisite’s energy-reduction target of 10% is not common practice and is considered beyond code compliance. 


  • ClerestoryIndirect sunlight delievered through clerestories like this helps reduce lighting loads as well as cooling loads. Photo – YRG Sustainability, Project – Cooper Union, New York A poorly designed envelope with a high-tech HVAC system is not, on the whole, efficient or cost-effective. Start with building orientation and passive design features first when looking for energy efficiency. Also look at envelope design, such as energy-efficient windows, walls and roof, before looking at HVAC and plug loads. HVAC may also be a good place to improve performance with more efficient equipment, but first reducing loads with smaller equipment can lead to even greater operational and upfront savings. A poorly designed envelope with a high-tech HVAC system is not, on the whole, efficient or cost-effective. 


  • Don’t plan on using onsite renewable energy generation (see EAc2) to make your building energy-efficient. It is almost always more cost-effective to make an efficient building, and then to add renewables like photovoltaics as the “icing” on the cake.


  • Some rules of thumb to reduce energy use are:

    • Program similar spaces together to reduce distribution losses 
    • Use a window-to-wall ratio below 40%, on average
    • Use a window-to-wall ratio below 20% on east and west sides, to reduce low-angle solar gain, and glare; 
    • Reduce direct solar gain with solar shades or building geometry and orientation
    • Distribute heating and cooling loads uniformly throughout all facades for a smaller system size. 
    • Design a tight and well-insulated building envelope to reduce the heating load and improve HVAC performance
    • Use right-sized and efficient heating and cooling systems
    • Consider onsite renewable energy generation.

  • Choosing your compliance path


  • Find the best credit compliance path based on your building type and energy-efficiency targets. Use the following considerations, noting that some projects are more suited to a prescriptive approach than others. 


  • Option 1: Whole Building Energy Simulation requires estimating the energy use of the whole building over a calendar year, using methodology established by ASHRAE 90.1-2007, Appendix G. Option 1 establishes a computer model of the building’s architectural design and all mechanical, electrical, domestic hot water, plug load, and other energy-consuming systems and devices. The model incorporates the occupancy load and a schedule representing projected usage in order to predict energy use. This compliance path does not prescribe any technology or strategy, but requires a minimum reduction in total energy cost of 10% (5% for an existing building), compared to a baseline building with the same form and design but using systems compliant with ASHRAE 90.1-2007. You can earn additional LEED points through EAc1 for cost reductions of 12% and greater (8% for existing buildings). 


  • Option 2: Prescriptive Compliance Path: ASHRAE Advanced Energy Design Guide refers to design guides published by ASHRAE for office, school, warehouse, and retail projects. These guides outline strategies to reduce energy use by 30% from ASHRAE 90.1-2001 levels, or an amount equivalent to a 10%–14% reduction from the ASHRAE 90.1-2007 standard. If you choose this compliance path, become familiar with the list of prescriptive requirements and commit to meeting them. (See the AEDG checklist in the Documentation Toolkit.) 


  • Option 3: Prescriptive Compliance Path: Advanced Buildings Core Performance Guide is another, more basic prescriptive path. It’s a good option if your project is smaller than 100,000 ft2, cannot pursue Option 2 (because there is not an ASHRAE guide for the building type), is not a healthcare facility, lab, or warehouse—or you would rather not commit to the energy modeling required for Option 1. Your project can be of any other building type (such as office or retail). To meet the prerequisite, you must comply with all requirements within Sections 1 and 2 of the guide. If you choose this path, become familiar with the list of activities and requirements and commit to meeting them. (See Resources for a link to the Core Performance Guide and the Documentation Toolkit for the checklist of prescriptive items.)


  • EAc1: Optimize Energy Performance uses the same structure of Options 1–3, so it makes sense to think about the credit and the prerequisite together when making your choice. In EAc1, Option 1 offers the potential for far more points than Options 2 and 3, so if you see your project as a likely candidate for earning those points, Option 1 may be best.


  • Hotels, multifamily residential, and unconventional commercial buildings may not be eligible for either Option 2 or Option 3, because the prescriptive guidance of these paths was not intended for them. Complex projects, unconventional building types, off-grid projects, or those with high energy-reduction goals are better off pursuing Option 1, which provides the opportunity to explore more flexible and innovative efficiency strategies and to trade off high-energy uses for lower ones. 


  • If your project combines new construction and existing building renovation then whatever portion contains more than 50% of the floor area would determine the energy thresholds.


  • Options 2 and 3 are suitable for small, conventional building types that may not have as much to gain from detailed energy modeling with Option 1. 


  • Meeting the prescriptive requirements of Options 2 and 3 is not common practice and requires a high degree of attention to detail by your project team. (See the Documentation Toolkit for the Core Performance Guide Checklist.) These paths are more straightforward than Option 1, but don’t think of them as easy. 


  • Options 2 and 3 require additional consultant time from architects and MEP engineers over typical design commitment, which means higher upfront costs. 


  • Option 1 references the mandatory requirements of ASHRAE 90.1-2007, which are more stringent than earlier LEED rating systems that referred to ASHRAE 90.1-2004.


  • Option 1 energy simulation provides monthly and annual operating energy use and cost breakdowns. You can complete multiple iterations, refining energy-efficiency strategies each time. Payback periods can be quickly computed for efficiency strategies using their additional first costs. A building’s life is assumed to be 60 years. A payback period of five years is considered a very good choice, and 10 years is typically considered reasonable. Consult the OPR for your owners’ goals while selecting your efficiency strategies. 


  • Option 1 energy simulation often requires hiring an energy modeling consultant, adding a cost (although this ranges, it is typically on the order of $0.10–$0.50/ft2 depending on the complexity). However, these fees produce high value in terms of design and decision-making assistance, and especially for complex or larger projects can be well worth the investment. 


  • All compliance path options may require both the architectural and engineering teams to take some time in addition to project management to review the prescriptive checklists, fill out the LEED Online credit form, and develop the compliance document. 


  • Option 1: Whole Building Energy Simulation


  • The architect, mechanical engineer, and lighting designer need to familiarize themselves and confirm compliance with the mandatory requirements of ASHRAE 90.1-2007, sections 5–9.


  • Use simple computer tools like SketchUp and Green Building Studio that are now available with energy analysis plug-ins to generate a first-order estimate of building energy use within a climate context and to identify a design direction. Note that you may need to refer to different software may not be the one used to develop complete the whole building energy simulations necessary for LEED certification. 


  • Energy modeling can inform your project team from the start of design. Early on, review site climate data—such as temperature, humidity and wind, available from most energy software—as a team. Evaluate the site context and the microclimate, noting the effects of neighboring buildings, bodies of water, and vegetation. Estimate the distribution of energy across major end uses (such as space heating and cooling, lighting, plug loads, hot water, and any additional energy uses), targeting high-energy-use areas to focus on during design.  


  • Energy use breakdown pie chartUse a preliminary energy use breakdown like this one to identify target areas for energy savings.Perform preliminary energy modeling in advance of the schematic design phase kick-off meeting or design charrette. The energy use breakdown can help identify targets for energy savings and point toward possible alternatives. 


  • For existing buildings, the baseline energy model can reflect the pre-renovation features like rather than a minimally ASHRAE-compliant building. This will help you achieve additional savings in comparison with the baseline.


  • Projects generating renewable energy onsite should use Option 1 to best demonstrate EAp2 compliance and maximize points under EAc1. Other options are possible but won’t provide as much benefit. Like any other project, model the baseline case as a system compliant with ASHRAE 90.1-2007, using grid-connected electricity, and the design case is an “as-designed” system also using grid-connected electricity. You then plug in 100% onsite renewable energy in the final energy-cost comparison table, as required by the performance rating method (PRM) or the modeling protocol of ASHRRAE 90.1 2007, Appendix G. (Refer to the sample PRM tables in the Documentation Toolkit for taking account of onsite renewable energy.


  • LEED divides energy-using systems into two categories: 

    • (i) Regulated loads. Most prominent systems—space heating, cooling, ventilation and pumps, lighting, and hot water—are regulated by ASHRAE and LEED so are termed “regulated” loads. Your energy model can provide insights into the energy use of all these systems. 
    • (ii) Non-regulated loads are those which are not directly associated with creating a comfortable environment, but with plug loads for machines. These include elevators, kitchen equipment, office equipment, televisions, and activity-oriented lighting, such as in hospitals. Though these are very large energy loads, they are not regulated by ASHRAE 90.1 or by LEED. Energy savings from specifying better equipment is not counted in energy models. It is typically expected that these non-regulated loads contribute to 25% of energy use.

  • The energy model itself will not account for any change in plug loads from the baseline case, even if your project is making a conscious effort to purchase Energy Star or other efficient equipment. Any improvement made in plug loads must be documented separately, using the exceptional calculation methodology (ECM), as described in ASHRAE 90.1-2007. These calculations determine the design case energy cost compared to the baseline case. They are included in the performance rating method (PRM) table or directly in the baseline and design case model. 


  • Besides energy modeling, you may need to use the exceptional calculation methodology (ECM) when any of the following situations occur: 

    • The energy software cannot carry out calculations for a specific systems like natural ventilation or unusual HVAC equipment.
    • Process loads are different in baseline and design cases and can influence total energy cost savings.
    • The proposed design can’t demonstrate savings with the modeling protocol and needs additional calculations. 

  • Some energy-modeling software tools have a daylight-modeling capability. Using the same model for both energy and IEQc8.1: Daylight and Views—Daylight can greatly reduce the cost of your modeling efforts.


  • Option 2: Prescriptive Compliance Path—ASHRAE Advanced Energy Design Guides


  • Provide a copy of the AEDG for office, retail, or warehouse, as applicable, to each team member as everyone, including the architect, mechanical and electrical engineers, lighting designer, and commissioning agents, are responsible for ensuring compliance. These are available to download free from the ASHRAE website. (See Resources.) 


  • Find your climate zone before attempting to meet any detailed prescriptive requirements. Climate zones vary by county, so be sure to select the right one. (See the Documentation Toolkit for a list of climate zones by county.)


  • Develop a checklist of all requirements, and assign responsible team members to accomplish them. Hold a meeting to walk the team through the AEDG checklist for your project’s climate zone. Clarify specific design goals and prescriptive requirements in the OPR for EAp1: Fundamental Commissioning.


  • Early access to the AEDG by each team member avoids last-minute changes that can have cascading, and costly, effects across many building systems. 


  • The AEDG prescriptive requirements include: 

    • a maximum allowable window-to-wall ratio;
    • continuous insulation on the outside of walls;
    • roofs and floor-slab minimum thermal performance;
    • minimum window and door thermal performance;
    • minimum boiler and chiller efficiencies;
    • and mandatory use economizers or heat recovery ventilation.

    If your project team is not comfortable following these guidelines, consider switching to Option 1, which gives you more flexibility. 


  • Although Option 2 is generally lower cost during the design phase than energy modeling, the compliance path is top heavy—it requires additional meeting time upfront for key design members. 


  • Option 3: Prescriptive—Advanced Buildings Core Performance Guide


  • Provide a copy of the New Buildings Institute Advanced Buildings: Core Performance Guide to each team member. The guide is available to download free from the NBI website. (See Resources.) 


  • The guide provides practical design assistance that can be used throughout the design process.


  • Walk your team through the project checklist to clarify design goals and prescriptive requirements. 


  • The guide provides an outline for approaching an energy-efficient design, in addition to a list of prescriptive measures. The first of its three sections emphasizes process and team interaction rather than specific building systems or features. Advise the owner to read through the guide in order to understand what is required of the architect and engineers. 


  • Section 1 in the guide focuses on best practices that benefit the project during the pre-design and schematic design stages, such as analyzing alternative designs and writing the owner’s project requirements (OPR). 


  • Section 2 of the Core Performance Guide describes architectural, lighting, and mechanical systems to be included. Section 3 is not required for EAp2 but includes additional opportunities for energy savings that can earn EAc1 points. 


  • The guide mandates that your team develop a minimum of three different design concepts to select from for best energy use.


  • Though they can be a little daunting at first glance, a majority of the guide’s requirements overlap with other LEED credits, such as EAp1: Fundamental Commissioning, IEQp1: Minimum Indoor Air Quality Performance, and IEQc6.1: Controllability of Systems—Lighting Controls


  • This compliance path is top-heavy due to upfront consultant time, but it provides adequate structure to ensure that your project is in compliance with the prerequisite requirements. For some projects it may be less expensive to pursue than Option 1. 

Schematic Design

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  • The owner should now have finalized the OPR with the support of the architect, as part of the commissioning credits EAp1 and EAc3. The goals identified here will help your team identify energy-reduction and occupant-comfort strategies.


  • Consider a broad range of energy-efficiency strategies and tools, including passive solar, daylighting, cooling-load reduction, and natural ventilation to reduce heating and cooling loads. 


  • Develop the basis of design (BOD) document in conjunction with your mechanical engineer and architect for EAp1: Fundamental Commissioning, noting key design parameters to help strategize design direction as outlined in the OPR. 


  • The OPR and BOD serve the larger purpose of documenting the owner’s vision and your team’s ideas to meet those goals. The BOD is intended to be a work-in-progress and should be updated at all key milestones in your project. Writing the document gives you an opportunity to capture the owner’s goals, whether just to meet the prerequisite or to achieve points under EAc1.


  • Confirm that your chosen compliance path is the most appropriate for your project, and make any changes now. Following a review with the design team and owner, ensure that everyone is on board with contracting an energy modeler for Option 1 or meeting all the prescriptive requirements under Options 2 or 3. 


  • Sometimes teams change from Option 1 to Options 2 or 3 very late in the design phase for various reasons including not realizing the cost of energy modeling. Making that change is risky, though: the prescriptive paths are all-or-nothing—you must comply with every item, without exception. Evaluate each requirement and consult with the contractor and estimator to ensure the inclusion of all activities within project management. 


  • To avoid costly, last-minute decisions, develop a comprehensive, component-based cost model as a decision matrix for your project. The model will help establish additional cost requirements for each energy conservation measure. It will also illustrate cost reductions from decreased equipment size, construction rendered unnecessary by energy conservation measures, and reduced architectural provisions for space and equipment access. (See the Documentation Toolkit for an example.)


  • Use envelope design and passive strategies to reduce the heating and cooling loads prior to detailed design of HVAC systems. Passive strategies can reduce heating and cooling loads, giving the engineer more options, including smaller or innovative systems.


  • Load reduction requires coordinated efforts by all design members including the architect, lighting designer, interior designer, information-technology manager, and owner. 

    • Architects can choose the optimum building orientation, select the appropriate envelope system and design it to be tight, and configure programming to utilize passive strategies as much as possible. 
    • Lighting designers help by harvesting daylight, making appropriate fixture selections, minimizing lighting layouts (fewer fixtures), providing maximum controls and daylight and occupancy sensors to reduce wasted light. 
    • Interior designers are critical for selecting reflective finishes to enhance daylighting and specifying Energy Star appliances. 
    • IT specialists are important, especially in buildings with data centers, for selection of computers and data-processing equipment that reduce the power load as well as cooling. 

  • Involving facilities staff in the design process can further inform key design decisions, helping ensure successful operation and low maintenance costs.


  • Encourage your design team to brainstorm design innovations and energy-reduction strategies. This provides a communication link among team members so they can make informed decisions. 


  • More energy-efficient HVAC equipment can cost more relative to conventional equipment. However, by reducing heating and cooling loads through good passive design, the mechanical engineer can often reduce the size and cost of the system. Reduced system size can save money through:

    • smaller chillers or boilers;
    • smaller fans, used less frequently;
    • smaller pumps and auxiliary systems;
    • smaller ducts;
    • and less square footage devoted to mechanical systems.

  • Review case studies of similar energy-efficient buildings in the same climate to provide helpful hints for selecting energy-efficiency measures. For example, a building in a heating-dominated climate can often benefit from natural ventilation and free cooling during shoulder seasons. (See Resources for leading industry journals showcasing success stories around the country and internationally.)


  • The relationship between first costs and operating costs can be complex. For example, more efficient windows will be more expensive, but could reduce the size and cost of mechanical equipment. A more efficient HVAC system may be more expensive, but will reduce operating costs. Play around with variables and different strategies to get the right fit for the building and the owner’s goals as stated in the OPR.


  • Option 1: Whole Building Energy Simulation


  • Review and confirm compliance with the mandatory requirements of all the relevant sections of ASHRAE 90.1-2007


  • Trust your project’s energy modeling task to a mechanical firm with a proven track record in using models as design tools, and experience with your building type.


  • Contract an energy modeling team for the project. These services may be provided by the mechanical engineering firm on the design team or by an outside consultant. Software used for detailed energy use analysis and submitted for final LEED certification must be accepted by the regulatory authority with jurisdiction, and must comply with paragraph G2.2 of ASHRAE Standard 90.1-2007. Refer to Resources for a list of Department of Energy approved energy-analysis software that may be used for LEED projects.


  • Design team members, including the architect and mechanical engineer at a minimum, need to work together to identify a percentage improvement goal for project energy use over the ASHRAE 90.1-2007-compliant baseline model. The percentage should be at least 10% to meet the prerequisite. 


  • Plan on initiating energy modeling during the design process, and use it to inform your design—preferably executing several iterations of the design as you improve the modeled energy performance. 


  • Ask the modeling consultant to develop an annual energy-use breakdown—in order to pick the “fattest” targets for energy reduction. A typical energy-use breakdown required for LEED submission and ASHRAE protocol includes: 

    • lighting;
    • space heating;
    • space cooling;
    • domestic hot water;
    • additional installed heat recovery, refrigeration, or heat-rejection systems;
    • ventilation fans and auxiliary pumps;
    • and equipment and plug loads. 

  • Identify critical areas in which to reduce loads. For example, in a data center, the plug loads are the largest energy load. Small changes in lighting density might bring down the energy use but represent only a small fraction of annual energy use. 


  • Don't forget that LEED (following ASHRAE) uses energy cost and not straight energy when it compares your design to a base case. That's important because you might choose to use a system that burns natural gas instead of electricity and come out with a lower cost, even though the on-site energy usage in kBtus or kWhs is higher. Generally you have to specify the same fuel in your design case and in the base case, however, so you can't simply switch fuels to show a cost savings


  • Explore and analyze design alternatives for energy use analyses to compare the cost-effectiveness of your design choices. For example, do you get better overall performance from a better window or from adding a PV panel? Will demand-control ventilation outperform increased ceiling insulation?


  • Simple, comparative energy analyses of conceptual design forms are useful ways to utilize an energy model at this stage. Sample scenarios include varying the area of east-facing windows and looking at 35% versus 55% glazing. Each scenario can be ranked by absolute energy use to make informed decisions during the design stage. 


  • If your project is using BIM software, the model can be plugged into the energy analysis software to provide quick, real-time results and support better decisions. 


  • Model development should be carried out following the PRM from ASHRAE 90.1-2007, Appendix G, and the LEED 2009 Design and Construction Reference Guide, Table in EAc1. In case of a conflict between ASHRAE and LEED guidelines, follow LEED.


  • Projects using district energy systems have special requirements. For EAp2, the proposed building must achieve the 10% energy savings without counting the effects of the district generation system. To earn points in EAc1 you can take advantage of the district system’s efficiency, but you have to run the energy model again to claim those benefits (see EAc1 for details). 


  • While you could run the required energy model at the end of the design development phase, simply to demonstrate your prerequisite compliance, you don’t get the most value that way in terms of effort and expense. Instead, do it early in the design phase, and run several versions as you optimize your design. Running the model also gives you an opportunity to make improvements if your project finds itself below the required 10% savings threshold.


  • The baseline model is the designed building with mechanical systems specified in ASHRAE 90.1-2007, Appendix G, for the specific building type, with a window-to-wall ratio at a maximum of 40%, and minimally code-compliant specifications for the envelope, lighting, and mechanical components. It can be developed as soon as preliminary drawings are completed. The baseline is compared to the design case to provide a percentage of reduction in annual energy use. To avoid any bias from orientation, you need to run the baseline model in each of the four primary directions, and the average serves as your final baseline figure. 


  • The design-case is modeled using the schematic design, orientation, and proposed window-to-wall ratio—¬the model will return design-case annual energy costs. Earn points by demonstrating percentage reductions in annual energy costs from the design to the baseline case. EAp2 is achieved if the design case is 10% lower than the baseline in new construction (or 5% less in existing building renovations). 


  • Provide as much project and design detail to the modeler as possible. A checklist is typically developed by the energy modeler, listing all the construction details of the walls, roof, slabs, windows, mechanical systems, equipment efficiencies, occupancy load, and schedule of operations. Any additional relevant information or design changes should be brought to the modeler’s attention as soon as possible. The more realistic the energy model is, the more accurate the energy use figure, leading to better help with your design.


  • Invite energy modelers to project meetings. An experienced modeler can often assist in decision-making during design meetings, even without running complete models each time. 


  • All known plug loads must be included in the model. The baseline and design-case models assume identical plug loads. If your project is deliberately attempting to reduce plug loads, demonstrate this by following the exceptional calculation method (ECM), as described in ASHRAE 90.1-2007, G2.5. Incorporate these results in the model to determine energy savings. 


  • For items outside the owner’s control—like lighting layout, fans and pumps—the parameters for the design and baseline models must be identical.


  • It can take anywhere from a few days to a few weeks to generate meaningful energy modeling results. Schedule the due dates for modeling results so that they can inform your design process.


  • Review the rate structure from your electrical utility. The format can inform your team of the measures likely to be most effective in reducing energy costs, especially as they vary over season, peak load, and additional charges beyond minimum energy use.


  • Performing a cost-benefit analysis in conjunction with energy modeling can determine payback times for all the energy strategies, helping the iterative design process.


  • Using energy modeling only to check compliance after the design stage wastes much of the value of the service, and thus your investment.


  • Option 2: Prescriptive—ASHRAE Advanced Energy Design Guides 


  • The architect and mechanical engineer should carefully read the applicable ASHRAE Advanced Energy Design Guide for office, warehouse, or retail projects, as applicable. 


  • Keep the owner abreast of the design decisions dictated by the standard. Fill in the team-developed checklist, within the climate zone table’s prescribed requirements, with appropriate envelope improvements, system efficiencies, and a configuration that meets the standard requirements. 


  • As a prescriptive path, this option relies heavily on following the requirement checklist, which is used throughout the design process to track progress. To assist design development, provide all critical team members—not limited to the architect, mechanical and electrical engineers, and lighting designer—with a checklist highlighting their appointed tasks.


  • The architect, mechanical engineer, and lighting designer need to discuss each requirement and its design ramifications. Hold these meetings every six to eight weeks to discuss progress and make sure all requirements are being met.


  • Confirm that your project team is comfortable with following all the prescribed requirements. If not, switch to Option 1: Whole Building Energy Simulation. 


  • The LEED Online credit form does not specify how to document each prescriptive requirement because they are so different for each project; it only requires a signed confirmation by the MEP for meeting AEDG requirements. You still have to provide documentation. Submit your checklist of requirements, and supporting information for each item, through LEED Online to make your case. If your project fails to meet even one requirement, it will fail to earn the prerequisite, thus jeopardizing LEED certification.  


  • Although energy modeling consultant costs are avoided by this option, additional staff time will be required to document and track compliance status, as compared with conventional projects.


  • Energy efficiency measures prescribed by the guide can be perceived as additional costs in comparison with conventional projects. However, they are easy to implement and are cost-effective pn the whole.


  • Option 3: Prescriptive Compliance Path—Advanced Buildings Core Performance Guide 


  • Become familiar with the Core Performance Guide early in the design phase to know the multiple requirements and all requisite documents.


  • Note that the guide demands additional time, attention, and integrated process from the design team as compared to conventional projects. It’s not just a list of prescriptive requirements, but a prescribed process for achieving energy efficiency goals. LEED Online documentation requires proof of all steps outlined in Sections 1 and 2, including three conceptual design options and meeting minutes. The project manager, architect, and mechanical engineer should read the complete Core Performance Guide carefully to know beforehand the prescriptive requirements in Sections 1 and 2. 


  • The project manager must take responsibility for ensuring that the requirement checklist is on track.


  • For Section 3, the design team needs to identify three or more of the listed strategies as possible targets for the project. 


  • Create a checklist of requirements and assign a responsible party to each item. 


  • The Core Performance Guide requires an integrated design contributed by the architect, mechanical and electrical engineers, and lighting designer. The project manager must take responsibility for shepherding and documenting the collaborative process to demonstrate compliance. 


  • A long documentation list can be overwhelming for your team, so create a detailed checklist with tasks delegated to individual team members, allowing each member to focus on assigned tasks. The checklist can function as a status tracking document and, finally, the deliverable for LEED Online.

Design Development

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  • The architect and engineer, and other project team members, continue to develop a high-performance building envelope with efficient mechanical and lighting systems. 


  • Constant communication and feedback among project team members, owner, and if possible, operational staff, during design development can minimize construction as well as operational costs and keep your project on schedule. 


  • If you change or go through value-engineering on any specifications, such as the solar-heat gain coefficient of glazing, for example, be aware of impacts on mechanical system sizing. Making changes like this might not pay off as much as it first appears.


  • Consider using building information modeling (BIM) tools to keep design decisions up to date and well documented for all team members.


  • Schedule delays can be avoided if all team members share their ideas and update documents during the design development process. 


  • Option 1: Whole Building Energy Simulation


  • The modeler completes the energy analysis of the selected design and system and offers alternative scenarios for discussion. The modeler presents the energy cost reduction results to the team, identifying the LEED threshold achieved.


  • It’s helpful for the energy modeling report to include a simple payback analysis to assist the owner in making an informed decision on the operational savings of recommended features. 


  • The architect and HVAC engineer should agree on the design, working with the cost estimator and owner.


  • Demonstrating reductions in non-regulated loads requires a rigorous definition of the baseline case. The loads must be totally equivalent, in terms of functionality, to the proposed design case. For example, reducing the number of computers in the building does not qualify as a legitimate reduction in non-regulated loads. However, the substitution of laptops for desktop computers, and utilization of flat-screen displays instead of CRTs for the same number of computers, may qualify as a reduction.


  • Residential and hospitality projects that use low-flow showers, lavatories, and kitchen sinks (contributing to WEp1) benefit from lower energy use due to reduced overall demand for hot water. However, for energy-savings calculations, these are considered process loads that must be modeled as identical in baseline and design cases, or you have the choice of demonstrating the savings with ECM for process loads. 


  • Perform daylight calculations in conjunction with energy modeling to balance the potentially competing goals of more daylight versus higher solar-heat gain resulting in high cooling loads. 


  • If your project is pursuing renewable energy, the energy generated is accounted for by using the PRM. These results provide information about whether the energy is contributing to EAc2: Onsite Renewable Energy. 


  • A cost-benefit analysis can help the owner understand the return on investment of big-ticket, energy-conserving equipment that lowers operating energy bills with a quick payback. 


  • Complete at least half of the energy modeling effort by the end of the design development stage. Help the design team to finalize strategy through intensive, early efforts in energy modeling. Once the team has a design direction, the modeler can develop a second model during the construction documents phase for final confirmation. 


  • If pursuing ECM for non-regulated loads, calculate energy saving for each measure separately if you are, for example, installing an energy-efficient elevator instead of a typical one so that the reduction would contribute to total building energy savings. Calculate the anticipated energy use of the typical elevator in kBTUs or kWh. Using the same occupancy load, calculate the energy use of the efficient elevator. Incorporate the savings into design case energy use within the PRM. Refer to the ECM strategy for detailed calculation guidelines. 


  • Option 2: Prescriptive Compliance Path—ASHRAE Advanced Energy Design Guides 


  • Ensure that all prescriptive requirements are incorporated into the design by the end of the design development stage.


  • Revisit the Advanced Energy Design Guides (AEDG) checklist to ensure that the design meets the prescriptive requirements.


  • Option 3: Prescriptive Compliance Path—Advanced Buildings Core Performance Guide


  • The mechanical engineer, lighting consultant, and architect revisit the checklist for an update on the requirements and how they are being integrated into the design. All prescriptive requirements should be specifically incorporated into the design by the end of the design development phase. 


  • The mechanical engineer and architect track the status of each requirement.


  • While the LEED Online credit form does not require detailed documentation for each Core Performance Guide requirement, it is important that each item be documented as required and reviewed by the rest of the team to confirm compliance, especially as further documentation may be requested by during review. Your design team should work with the owner to identify cost-effective strategies from Section 3 that can be pursued for the project. 

Construction Documents

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  • Construction documents clearly detail the architectural and mechanical systems that address energy-efficiency strategies.  


  • Confirm that specifications and the bid package integrate all equipment and activities associated with the project. 


  • If the project goes through value engineering, refer to the OPR and BOD to ensure that no key comfort, health, productivity, daylight, or life-cycle cost concerns are sacrificed.


  • During the budget estimating phase, the project team may decide to remove some energy-saving strategies that have been identified as high-cost items during the value-engineering process. However, it is very important to help the project team understand that these so-called add-ons are actually integral to the building’s market value and the owner’s goals. 


  • Removing an atrium, for example, due to high cost may provide additional saleable floor area, but may also reduce daylight penetration while increasing the lighting and conditioning loads.  


  • Option 1: Whole Building Energy Simulation


  • Although this prerequisite is a design-phase submittal, it may make sense to submit it, along with EAc1, after construction. Your project could undergo changes during construction that might compel a new run of the energy model to obtain the latest energy-saving information. Waiting until the completion of construction ensures that the actual designed project is reflected in your energy model.


  • Create a final energy model based completely on construction document drawings—to confirm actual energy savings as compared to ASHRAE 90.1-2007 requirements. An energy model based on the construction documents phase will provide realistic energy-cost savings and corresponding LEED points likely to be earned. 


  • Make sure the results fit the LEED Online credit form requirements. For example, the unmet load hours have to be less than 300 and process loads will raise a red flag if they’re not approximately 25%. If any of the results are off mark, take time to redo the model. Time spent in design saves more later on in the LEED review process. 


  • Option 2: Prescriptive Compliance Path—ASHRAE Advanced Energy Design Guides


  • Finalize all design decisions and confirm that you’ve met all of the prescriptive requirements. Your team must document the checklist with relevant project drawings, including wall sections, specifications, and the MEP drawing layout.


  • Value engineering and other factors can result in design changes that eliminate certain energy features relevant to the prerequisite. As this compliance path is prescriptive, your project cannot afford to drop even one prescribed item.


  • Option 3: Prescriptive Compliance Path—Advanced Buildings Core Performance Guide


  • Finalize all design decisions and confirm that you’ve met all of the prescriptive requirements. Your team must document the checklist with relevant project drawings, including wall sections, specifications, and the MEP drawing layout.


  • Value engineering and other factors can result in design changes that eliminate certain energy features relevant to the credit. As this compliance path is prescriptive, your project cannot afford to drop even one listed item. Although perceived as high-cost, prescriptive requirements lower energy costs during operation and provide a simple payback structure. 

Construction

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  • The architect and mechanical engineer review the shop drawings to confirm the installation of the selected systems. 


  • The commissioning agent and the contractor conduct functional testing of all mechanical equipment in accordance with EAp1: Fundamental Commissioning and EAc3: Enhanced Commissioning. 


  • Find your Energy Star rating with EPA’s Target Finder tool if your building type is in the database. Input your project location, size, and number of occupants, computers, and kitchen appliances. The target may be a percentage energy-use reduction compared to a code-compliant building, or “anticipated energy use” data from energy model results. Add information about your fuel use and rate, then click to “View Results.” Your Target Finder score should be documented at LEED Online.


  • Plan for frequent site visits by the mechanical designer and architect during construction and installation to make sure construction meets the design intent and specifications. 


  • Emphasize team interaction and construction involvement when defining the project scope with key design team members. Contractor and designer meetings can help ensure correct construction practices and avoid high change-order costs for the owner. 


  • Subcontractors may attempt to add a premium during the bidding process for any unusual or unknown materials or practices, so inform your construction bidders of any atypical design systems at the pre-bid meeting.


  • Option 1: Whole Building Energy Simulation


  • The energy modeler ensures that any final design changes have been incorporated into the updated model.


  • Upon finalizing of the design, the responsible party or energy modeler completes the LEED Online submittal with building design inputs and a PRM result energy summary. 


  • Although EAp2 is a design phase submittals, it may make sense to submit it (along with EAc1) after construction. Your project could undergo changes during construction that might require a new run of the energy model. Waiting until the completion of construction ensures that your actual designed project is reflected. On the other hand, it gives you less opportunity to respond to questions that might come up during a LEED review. 


  • Include supporting documents like equipment cut sheets, specifications and equipment schedules to demonstrate all energy efficiency measures claimed in the building. 


  • It common for the LEED reviewers to make requests for more information. Go along with the process—it doesn’t mean that you’ve lost the credit. Provide as much information for LEED Online submittal as requested and possible. 


  • Option 2: Prescriptive Compliance Path—ASHRAE Advanced Energy Design Guides (AEDG)


  • The design team completes the LEED Online documentation, signing off on compliance with the applicable AEDG, and writing the narrative report on the design approach and key highlights.


  • During LEED submission, the project team needs to make an extra effort to support the prerequisite with the completed checklist and the required documents. Although the LEED rating system does not list detailed documentation, it is best practice to send in supporting documents for the prescriptive requirements from the AEDG. The supporting documents should include relevant narratives, wall sections, mechanical drawings, and calculations. 


  • Although the LEED Online sign-off does not include a checklist of AEDG requirements, it assumes that the team member is confirming compliance with all detailed requirements of the guide. 


  • Option 3: Prescriptive Compliance Path—Advanced Building Core Performance Guide


  • The design team completes the LEED Online credit form, signing off on compliance with the Core Performance Guide, and writing the narrative report on the design approach and key highlights.


  • During LEED submission, your project team needs to make an extra effort to support the prerequisite with the completed checklist and the required documents. Although not every requirement may be mentioned in the LEED documentation, the supporting documents need to cover all requirements with narratives, wall sections, mechanical drawings, and calculations. 


  • Many of this option’s compliance documents are common to other LEED credits or design documents, thus reducing duplicated efforts. 

Operations & Maintenance

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  • Develop an operations manual with input from the design team in collaboration with facility management and commissioning agent if pursuing EAc3: Enhanced Commissioning. 


  • The benefit of designing for energy efficiency is realized only during operations and maintenance. Record energy use to confirm that your project is saving energy as anticipated. If you are not pursuing EAc5: Measurement and Verification, you can implement tracking procedures such as reviewing monthly energy bills or on-the-spot metering.


  • Some energy efficiency features may require special training for operations and maintenance personnel. For example, cogeneration and building automation systems require commissioning and operator training. Consider employing a trained professional to aid in creating operation manuals for specialty items. 


  • Energy-efficiency measures with a higher first cost often provide large savings in energy use and operational energy bills. These credit requirements are directly tied to the benefits of efficient, low-cost operations.

  • USGBC

    Excerpted from LEED 2009 for New Construction and Major Renovations

    EA Prerequisite 2: Minimum energy performance

    Required

    Intent

    To establish the minimum level of energy efficiency for the proposed building and systems to reduce environmental and economic impacts associated with excessive energy use.

    Requirements

    Projects that registered on or after April 8, 2016 must demonstrate an 18% improvement for new buildings, or a 14% improvement for major renovations to existing buildings.
    Option 1. Whole building energy simulation

    Demonstrate a 10% improvement in the proposed building performance rating for new buildings, or a 5% improvement in the proposed building performance rating for major renovations to existing buildings, compared with the baseline building performanceBaseline building performance is the annual energy cost for a building design, used as a baseline for comparison with above-standard design. rating.

    Calculate the baseline building performance rating according to the building performance rating method in Appendix G of ANSI/ASHRAE/IESNA Standard 90.1-2007 (with errata but without addenda1) using a computer simulation model for the whole building project. Projects outside the U.S. may use a USGBC approved equivalent standard2.

    Appendix G of Standard 90.1-2007 requires that the energy analysis done for the building performance rating method include all energy costs associated with the building project. To achieve points using this credit, the proposed design must meet the following criteria:

    • Comply with the mandatory provisions (Sections 5.4, 6.4, 7.4, 8.4, 9.4 and 10.4) in Standard 90.1-2007 (with errata but without addenda1) or USGBC approved equivalent.
    • Inclusion of all the energy costs within and associated with the building project.
    • Compare against a baseline building that complies with Appendix G of Standard 90.1-2007 (with errata but without addenda1) or USGBC approved equivalent. The default process energy cost is 25% of the total energy cost for the baseline building. If the building’s process energy cost is less than 25% of the baseline building energy cost, the LEED submittal must include documentation substantiating that process energy inputs are appropriate.

    For the purpose of this analysis, process energy is considered to include, but is not limited to, office and general miscellaneous equipment, computers, elevators and escalators,kitchen cooking and refrigeration, laundry washing and drying, lighting exempt from the lighting power allowance (e.g., lighting integral to medical equipment) and other (e.g., waterfall pumps).

    Regulated (non-process) energy includes lighting (for the interior, parking garage, surface parking, façade, or building grounds, etc. except as noted above), heating, ventilation and air conditioning (HVAC) (for space heating, space cooling, fans, pumps, toilet exhaust, parking garage ventilation, kitchen hood exhaust, etc.), and service water heating for domestic or space heating purposes.

    Process loads must be identical for both the baseline building performance rating and the proposed building performance rating. However, project teams may follow the exceptional calculation method (ANSI/ASHRAE/IESNA Standard 90.1-2007 G2.5) or USGBC approved equivalent to document measures that reduce process loads. Documentation of process load energy savings must include a list of the assumptions made for both the base and the proposed design, and theoretical or empirical information supporting these assumptions.

    Projects in California may use Title 24-2005, Part 6 in place of ANSI/ASHRAE/IESNA Standard 90.1-2007 for Option 1.

    OR

    Option 2 is not an eligible compliance option for projects that registered on or after April 8, 2016.
    Option 2. Prescriptive compliance path: ASHRAE Advanced Energy Design Guide

    Comply with the prescriptive measures of the ASHRAE Advanced Energy Design Guide appropriate to the project scope, outlined below. Project teams must comply with all applicable criteria as established in the Advanced Energy Design Guide for the climate zoneOne of five climatically distinct areas, defined by long-term weather conditions which affect the heating and cooling loads in buildings. The zones were determined according to the 45-year average (1931-1975) of the annual heating and cooling degree-days (base 65 degrees Fahrenheit). An individual building was assigned to a climate zone according to the 45-year average annual degree-days for its National Oceanic and Atmospheric Administration (NOAA) Division. in which the building is located. Projects outside the U.S. may use ASHRAE/ASHRAE/IESNA Standard 90.1-2007 Appendices B and D to determine the appropriate climate zone.

    Path 1. ASHRAE Advanced Energy Design Guide for Small Office Buildings 2004

    The building must meet the following requirements:

    • Less than 20,000 square feet (1,800 square meters).
    • Office occupancy.
    Path 2. ASHRAE Advanced Energy Design Guide for Small Retail Buildings 2006

    The building must meet the following requirements:

    • Less than 20,000 square feet (1,800 square meters).
    • Retail occupancy.
    Path 3. ASHRAE Advanced Energy Design Guide for Small Warehouses and Self Storage Buildings 2008

    The building must meet the following requirements:

    • Less than 50,000 square feet (4,600 square meters).
    • Warehouse or self-storage occupancy.

    OR

    Option 3 is not an eligible compliance option for projects that registered on or after April 8, 2016.
    Option 3. Prescriptive compliance path: Advanced Buildings™ Core Performance™ Guide

    Comply with the prescriptive measures identified in the Advanced Buildings™ Core Performance™ Guide developed by the New Buildings Institute. The building must meet the following requirements:

    • Less than 100,000 square feet (9,300 square meters).
    • Comply with Section 1: Design Process Strategies, and Section 2: Core Performance Requirements.
    • Health care, warehouse and laboratory projects are ineligible for this path.

    Projects outside the U.S. may use ASHRAE/ASHRAE/IESNA Standard 90.1-2007 Appendices B and D to determine the appropriate climate zone.

    OR

    Option 4. Brazil compliance path: PBE Edifica

    Projects in Brazil that are certified at the “A” level under the Regulation for Energy Efficiency Labeling (PBE Edifica) program for all attributes (Envelope, Lighting, HVAC) achieve this prerequisite. The following building types cannot achieve this prerequisite using this option: Healthcare, Data Centers, Manufacturing Facilities, Warehouses, and Laboratories.

    1Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.

    2 Projects outside the U.S. may use an alternative standard to ANSI/ASHRAE/IESNA Standard 90.1-2007 if it is approved by USGBC as an equivalent standard using the process identified in the LEED 2009 Green Building Design and Construction Global ACP Reference Guide Supplement.

    Pilot ACPs Available

    The following pilot alternative compliance path is available for this prerequisite. See the pilot credit library for more information.

    EApc95: Alternative Energy Performance Metric ACP

    Potential Technologies & Strategies

    Design the building envelope and systems to meet baseline requirements. Use a computer simulation model to assess the energy performance and identify the most cost-effective energy efficiency measures. Quantify energy performance compared with a baseline building.

    If local code has demonstrated quantitative and textual equivalence following, at a minimum, the U.S. Department of Energy (DOE) standard process for commercial energy code determination, then the results of that analysis may be used to correlate local code performance with ANSI/ASHRAE/IESNA Standard 90.1-2007. Details on the DOE process for commercial energy code determination can be found at http://www.energycodes.gov/implement/
    determinations_com.stm.

    FOOTNOTES

    1 Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.

    2 Projects outside the U.S. may use an alternative standard to ANSI/ASHRAE/IESNA Standard 90.1‐2007 if it is approved by USGBC as an equivalent standard using the process located at www.usgbc.org/leedisglobal

Organizations

Database of State Incentives for Renewables and Efficiency (DSIRE)

This database shows state-by-state incentives for energy efficiency, renewable energy, and other green building measures. Included in this database are incentives on demand control ventilation, ERVs, and HRVs.


New York State Energy Research and Development Authority (NYSERDA)

Useful web resource with information on local/regional incentives for energy-efficiency programs.


American Council for an Energy-Efficient Economy

ACEEE is a nonprofit organization dedicated to advancing energy efficiency through technical and policy assessments; advising policymakers and program managers; collaborating with businesses, public interest groups, and other organizations; and providing education and outreach through conferences, workshops, and publications. 


New Buildings Institute

The New Buildings Institute is a nonprofit, public-benefits corporation dedicated to making buildings better for people and the environment. Its mission is to promote energy efficiency in buildings through technology research, guidelines, and codes.


U.S. Department of Energy, Building Energy Codes Program

The Building Energy Codes program provides comprehensive resources for states and code users, including news, compliance software, code comparisons, and the Status of State Energy Codes database. The database includes state energy contacts, code status, code history, DOE grants awarded, and construction data. The program is also updating the COMcheck-EZ compliance tool to include ANSI/ASHRAE/IESNA 90.1–2007. This compliance tool includes the prescriptive path and trade-off compliance methods. The software generates appropriate compliance forms as well. 


Rensselaer Polytechnic Institute: Daylighting Resources

Research center at RPI provides access to a wide range of  daylighting resources, case studies, design tools, reports, publications and more.


IBPSA

International association of energy modelers with various national and local chapters. 


Architecture 2030

Non-profit organization aiming at design community to increase collaboration for designing energy efficient buildings.


Low Impact Hydropower Institute

The Low Impact Hydropower Institute is a non-profit organization and certification body that establishes criteria against which to judge the environmental impacts of hydropower projects in the United States.


U.S. Department of Energy Building Technologies Program

The Building Technologies Program (BTP) provides resources for commercial and residential building components, energy modeling tools, building energy codes, and appliance standards including the Buildings Energy Data Book, High Performance Buildings Database and Software Tools Directory.

Web Tools

Energy Analysis Tools

This website discusses the step-by-step process for energy modeling.


Advanced Buildings Technologies and Practices

This online resource, supported by Natural Resources Canada, presents energy-efficient technologies, strategies for commercial buildings, and pertinent case studies.


U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy

This website is a comprehensive resource for U.S. Department of Energy information on energy efficiency and renewable energy and provides access to energy links and downloadable documents. 


U.S. EPA, Combined Heat and Power Partnership

Information on cogenerationThe simultaneous production of electric and thermal energy in on-site, distributed energy systems; typically, waste heat from the electricity generation process is recovered and used to heat, cool, or dehumidify building space. Neither generation of electricity without use of the byproduct heat, nor waste-heat recovery from processes other than electricity generation is included in the definition of cogeneration., also called combined heat and power, is available from EPA through the CHPCombined heat and power (CHP), or cogeneration, generates both electrical power and thermal energy from a single fuel source. Partnership. The CHP Partnership is a voluntary program seeking to reduce the environmental impact of power generation by promoting the use of CHP. The Partnership works closely with energy users, the CHP industry, state and local governments, and other clean energy stakeholders to facilitate the development of new projects and to promote their environmental and economic benefits. 


Advanced Energy Design Guides

Free download of AHSRAE energy savings guide, use for Option 2.


Lawrence Berkeley Lab: Building Technologies Department

Research warehouse for strategies and case studies of energy efficiency in buildings.


Efficient Windows Collaborative

An online window selection tool with performance characteristics.


Whole Building Design Guide (WBDG)

This website lays out design process for developing an energy efficient building.


AIA Sustainability 2030 Toolkit

This website discusses ways to improve design for lower energy demand as they relate to the AIA 2030 challenge.


Windows for High-Performance Commercial Buildings

This website includes discussion of design issues, materials and assemblies, window design decisions and case studies. 


California Integrated Waste Management Board: Environmental and Economic Assessment Tools

This site lists multiple web-based and downloadable tools that can be used for energy analyses.


DEER: Database for Energy Efficient Resource

This database is maintainted by the California Energy Commission and lists resources related to energy use and efficiency. 


Energy Design Resources - CA

Energy design tools are available to be used for free online or available to download.


Building Materials Property Table

This website lists performance characteristics for various envelope materials. 


One Building

This is an online forum of discussion for energy efficiency, computer model software users.


EPA’s Target Finder

Target Finder is a goal-setting tool that informs your design team about their project’s energy performance as compared to a national database of projects compiled by the EPA.


Building Energy Software Tools Directory

This directory provides information on 406 building software tools for evaluating energy efficiency, renewable energy, and sustainability in buildings.


EnergyPlus Format Weather Data Resources

Weather data for more than 2100 locations are available in EnergyPlus weather format.


DOE-2 Format Weather Data Resources

Weather data for U.S. and Non-U.S. locations in BIN format.


BEMbook – Building Energy Modeling Book

A web-based, free content project by IBPSA-USA to develop an online compendium of the domain of Building Energy Modeling (BEM). The intention is to delineate a cohesive body of knowledge for building energy modeling.

Technical Guides

Advanced Buildings Core Performance Guide

A guide for achieving energy efficiency in new commercial buildings, referenced in the LEED energy credits.


ENERGY STAR Building Upgrade Manual

This manual is a strategic guide for planning and implementing energy-saving building upgrades. It provides general methods for reviewing and adjusting system control settings, plus procedures for testing and correcting calibration and operation of system components such as sensors, actuators, and controlled devices.


Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 – Design & Construction

This document is USGBC’s second (v2.0) major release of guidance for district or campus thermal energy in LEED, and is a unified set of guidance comprising the following an update to the original Version 1.0 guidance released May 2008 for LEED v2.x and the initial release of formal guidance for LEED v2009.


COMNET Commercial Buildings Energy Modeling Guidelines and Procedures

This manual offers guidance to building energy modelers, ensuring technically rigorous and credible assessment of energy performance of commercial and multifamily residential buildings. It provides a streamlined process that can be used with various existing modeling software and systems, across a range of programs.


2009 ASHRAE Handbook of Fundamentals, Chapter 19

Chapter 19 is titled, “Energy Estimating and Modeling Methods”. The chapter discusses methods for estimating energy use for two purposes: modeling for building and HVAC system design and associated design optimization (forward modeling), and modeling energy use of existing buildings for establishing baselines and calculating retrofit savings (data-driven modeling).


Treatment of Distric or Campus Thermal Energy in LEED v2 and LEED 2009 (Updated August 13, 2010)

Required reference document for DES systems in LEED energy credits.

Publications

ANSI/ASHRAE/IESNA Standard 90.1–2007 User’s Manual (ASHRAE).

ASHRAE writes standards for the purpose of establishing consensus for: 1) methods of test for use in commerce and 2) performance criteria for use as facilitators with which to guide the industry.


Energy Information Administration

Energy statistics from the U.S. government.


New Buildings Institute— Advanced Lighting Guidelines: 2003 Edition

This guide includes instructional graphics and superior lighting design solutions for varying types of buildings and spaces, from private offices to big box retail stores.


Building Energy Performance News

This website offers information on energy efficiency in buildings, highlighting success stories, breakthrough technology, and policy updates.


GreenSource magazine

Bimonthly publication on case studies and new technologies for energy efficiency in commercial buildings. 


AIA Local Leaders in Sustainability: Green Incentives

AIA publication highlighting local and state green building incentives.


Federal Research and Devlopment Agenda for Net-Zero Energy, High-Performance Green Buildings

2008 guidelines and performance goals from the National Science and Technology Council.


Energy Design Resources (EDR) Simulation Guidebooks

Information about energy-efficient building practices available in EDR's Design Briefs, Design Guidelines, Case Studies, and Technology Overviews.

Software Tools

Building Energy Software Tools Directory

DOE tools for whole building analyses, including energy simulation, load calculation, renewable energy, retrofit analysis and green buildings tools.


Building and Fire Research Laboratory

This is a computer program that predicts the one-dimensional transfer of heat and moisture.


DesignBuilder and EnergyPlus

DesignBuilder is a Graphical User Interface to EnergyPlus. DesignBuilder is a complete 3-D graphical design modeling and energy use simulation program providing information on building energy consumption, CO2Carbon dioxide emissions, occupant comfort, daylighting effects, ASHRAE 90.1 and LEED compliance, and more.


Integrated Environmental Solutions – Virtual Environment Pro / Apache

IES VE Pro is an integrated computing environment encompassing a wide range of tasks in building design including model building, energy/carbon, solar, light, HVAC, climate, airflow, value/cost and egress.

Advanced Energy Design Guide Checklist

Option 2: Prescriptive Compliance Path

Use this checklist of prescriptive requirements (with sample filled out) to have an at-a-glance picture of AEDG requirements for Option 2, and how your project is meeting them.

Advanced Buildings Core Performance Guide (CPG) Checklist

Option 3

This spreadsheet lists all the requirements for meeting EAp2 – Option 3 and and EAc1 – Option 3. You can review the requirements, assign responsible parties and track status of each requirement through design and construction.

Energy Simulation Narrative

Option 1

Sometimes the energy simulation software being used to demonstrate compliance with Option 1 doesn't allow you to simulate key aspects of the design. In this situation you'll need to write a short sample narrative, as in these examples, describing the situation and how it was handled.

Equipment and Product Cut Sheets

All Options

In your supporting documentation, include spec sheets of equipment described in the Option 1 energy model or Options 2–3 prescriptive paths.

PRM Table

Option 1

This is a sample building energy performance and cost summary using the Performance Rating Method (PRM). Electricity and natural gas use should be broken down by end uses including space heating, space cooling, lights, task lights, ventilation fans, pumps, and domestic hot water, at the least.

Tariff Charges

Option 1

Option 1 calculates savings in annual energy cost, but utility prices may vary over the course of a year. This sample demonstrates how to document varying electricity tariffs.

Modeled Energy Reductions

Option 1

This graph, for an office building design, shows how five overall strategies were implemented to realize energy savings of 30% below an ASHRAE baseline. (From modeling conducted by Synergy Engineering, PLLC.)

U.S. Climate Zones

All Options

The climate zones shown on this Department of Energy map are relevant to all options for this credit.

Appendix G Fan Power Calculator

Option 1

This spreadsheet, provided here by 7group, can be used to calculate the fan volume and fan power for Appendix G models submitted for EAp2/EAc1.  Tabs are included to cover both ASHRAE 90.1-2004 and 90.1-2007 Appendix G methodologies.

LEED Online Forms: NC-2009 EA

Sample LEED Online forms for all rating systems and versions are available on the USGBC website.

Design Submittal

PencilDocumentation for this credit can be part of a Design Phase submittal.

3617 Comments

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PAULA HERNANDEZ MRS. INGENIERO MARIO PEDRO HERNANDEZ
Jul 27 2016
LEEDuser Member
980 Thumbs Up

Process Loads

Hello,
I am modeling a bulding where wine is made (don´t know how to say it in English, sorry),
the thing is that there are many spaces in the project that have AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition) 2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork. just to process or store the wine under certain conditions of temperature and humidity.
I have some doubts about how to model this spaces:
1. I assume they are process loads.
2. If this assumption is ok, I would need to include the AHUs power inpunt and it´s schedule both in the Baseline and the Project buildings.
3. On the same line of thinking, this will appear as a "Process Load #1".
4. If the previous assumption is wrong, I have to model de project building as it is projected and the baseline building with it´s corresponding air conditioning system, and it will be one more system, NOT A PROCESS LOAD.
I will appreciatte any dicsussion on this,
thank you,
Paula

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Marcus Sheffer LEED Fellow, 7group Jul 27 2016 LEEDuser Expert 61838 Thumbs Up

A winery!

If these system are only used to condition the wine and not for any people in the spaces then they are process. However, if the conditioning also serves the people in these spaces then they are not. In this situation I think they are not exclusively process so model the Proposed as designed and The Baseline according to Appendix G.

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PAULA HERNANDEZ MRS., INGENIERO MARIO PEDRO HERNANDEZ Jul 27 2016 LEEDuser Member 980 Thumbs Up

Thank you for the data!!, now I know what I am simulating!,
Just one more comment, air consitioning conditions are not intended for the people there to be comfort, but for the wine to be maintained as it needs, temperature set point about 60 ºF and relative humidity about 70%.
Does it still apply as NO PROCESS?
Thank you,

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Marcus Sheffer LEED Fellow, 7group Jul 27 2016 LEEDuser Expert 61838 Thumbs Up

Sounds like they need a basement (or cave) which is where I store my wine.

I will double check with the engineers in my office and get back to you.

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PAULA HERNANDEZ MRS., INGENIERO MARIO PEDRO HERNANDEZ Jul 28 2016 LEEDuser Member 980 Thumbs Up

Actually they bottled the wine and store the bottles in this place,
A very good one I have to say.

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Marcus Sheffer LEED Fellow, 7group Jul 28 2016 LEEDuser Expert 61838 Thumbs Up

What is the wine?

Given the conditions you indicate we do agree that this is a process load. The conditions are clearly for the product and not the people who are periodically in the space. Sounds basically like a high temperature refrigerated warehouse.

If they only had a cave they could just get rid of this system and save energy!

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PAULA HERNANDEZ MRS., INGENIERO MARIO PEDRO HERNANDEZ Jul 28 2016 LEEDuser Member 980 Thumbs Up

Thank you Marcus,
We have every kind of space, we have a cave, we have above grade buildings where they bottled and store the grapes/wine, we have everything in there,
I will do as you say, and maybe I will ask you something again later, regarding this same issue.
Yes, the wine is very good.

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Marcus Sheffer LEED Fellow, 7group Jul 28 2016 LEEDuser Expert 61838 Thumbs Up

Perhaps I was not clear - can you share the name of the winery? I like good wine and happily answer LEED User questions in exchange for good wine recommendations! :-)

Good luck with the project.

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VICTOR MORENO TECHNICAL DIRECTOR ISOLANA AHORRO ENERGÉTICO SL
Jul 21 2016
Guest
383 Thumbs Up

Renewable energy - EAc1

I have modeled a proposed building including PV and solar thermal systems.
The energy generated of PV system is excluded of End Uses results, but the energy generateds of Solar thermal is integrated in DHWDomestic hot water (DHW) is water used for food preparation, cleaning and sanitation and personal hygiene, but not heating. system and it is subtracted of DHW energy consumption.
So, I include only PV energy generated in Table L-1 of LEED Template, i don´t include the energy generated by Solar Thermal.
However i include PV and Solar thermal energy in LEED Templated of EAc2.
Is the right approach?

Secondly, the reviewer request me to justify calculations of renewable energy generation. The calculations are based in Energy simulation results (Energy Plus).
My answer must be that renewable generation is based on Energy Simulation? and inform you thet see the results of renewable energy generated in Annual Building Utility Performance Summary (Energy Plus)?
Is the right approach?

Thanks!!

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Marcus Sheffer LEED Fellow, 7group Jul 21 2016 LEEDuser Expert 61838 Thumbs Up

That will probably work. Technically you should include both the solar thermal and PV in the renewable energy table on the form. If the only savings for service hot water is the solar system then it should be straight forward and not necessary to enter the savings in Table L-1. However, if you have any additional service hot water savings, like hot water demand reduction or back up system efficiency, then it is helpful to the reviewer to separate these so they can see the amount of savings associated with each. I would include a narrative explaining the breakdown of the savings if it is more than just the solar thermal system.

You should provide additional information on how the savings were calculated. If generated by the modeling software provide reports showing the inputs (could be screen captures) and outputs along with an explanation of the calculations.

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VICTOR MORENO TECHNICAL DIRECTOR , ISOLANA AHORRO ENERGÉTICO SL Jul 22 2016 Guest 383 Thumbs Up

ThankS Marcus.

I´m sorry for posting the same question in different forum. i was handling mobile device and the question don´t displayed as posted. Sorry.

I point option "Automatic Cost Calculation: Renewable energy cost savings will be based on the "virtual" energy rate defined in Section 1.5." on SECTION 1.8 - ON-SITE RENEWABLE ENERGY of the LEED Template. So, the renewable energy generated is subtracted of Facility Energy consumption.

If I included the solar thermal energy in Table L-1, this salved energy is count twice. Therefore I think that i have to include only PV energy in Table L-1.
Is the right approach?

Secondly, to included the total energy consumption of the Proposed building in EAc2 LEED Template, I have to add the Solar thermal energy generated to End use result of Energy Plus? Because the End use of simulation result include the saving of Soler thermal Energy.

Thanks in advanced!!!

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Marcus Sheffer LEED Fellow, 7group Jul 23 2016 LEEDuser Expert 61838 Thumbs Up

That approach should work just make sure to explain to the reviewer that the solar thermal is included in the Proposed modeling results. You are correct that you do not want to count it twice.

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Judhajit Chakraborty Building Performance Specialist WSP Built Ecology
Jul 19 2016
LEEDuser Member
55 Thumbs Up

Lighting in unconditioned exterior concourses

Project Location: United States

I am working on a stadium project where the main concourses are exterior and tucked under the seating bowl; within the concourse are restrooms, concessions, etc. Some of the enclosed spaces within the concourse are conditioned; most are not. All of these enclosed spaces are zones in my energy model with interior LPDs, but the concourse is not because it is an unenclosed space, completely open to the outside. My question is regarding the lighting within the concourse, and whether or not it would be considered interior or exterior lighting. There isn't category in ASHRAE 90.1-2007 Table 9.4.5 that applies to this type of "exterior" lighting. I'm tempted to put them under Plaza Areas / Walkways 10 ft or greater, but I'm not sure if this is the right way to go. Thanks for any input!

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Marcus Sheffer LEED Fellow, 7group Jul 20 2016 LEEDuser Expert 61838 Thumbs Up

Since it is a covered space I would tend to treat it as interior corridor. None of the exterior lighting includes spaces that are substantially covered. By way of example take a freestanding parking garage. The parking on the roof is considered exterior. The parking on the decks below are considered interior. These concourses are more like the lower parking decks than they are like an exterior plaza or walkway.

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Thomas Leary Executive Vice President JDB Engineering, Inc.
Jul 19 2016
Guest
5 Thumbs Up

Modeling hotel room lighting

Project Location: United States

Hello,
Current project has both hardwired permanent lighting fixtures and table lamps plugged into switched receptacles in the hotel rooms of a highrise.
Per ASHRAE table G3.1 section 6:
b. States proposed building lighting shall meet 9.1.3 and 9.1.4 which excludes plug lighting as they are not permanent fixtures.
d. States to include "all" lighting.
Exception to d. states to match the proposed and baseline building if the lighting is not shown in the documents; however, they are in the design documents.
Baseline says to use lighting power set equal to the maximum allowed for the corresponding method and category in Section 9.2.
Proposed b. and d. seem to be contradictory and assuming the base buildingThe base building includes elements such as the structure, envelope, and building-level mechanical systems, such as central HVAC, etc. matched ASHRAE allowable lighting levels, following b. would unfairly cause the proposed building to perform better than reality.
Some information I found on the USGBC website seem to suggest the plug fixtures should be included as non-regulated process loads in both the proposed and base building.

Any insight/advice would be greatly appreciated.

Thank you

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Marcus Sheffer LEED Fellow, 7group Jul 20 2016 LEEDuser Expert 61838 Thumbs Up

Hey Tom,

Your first assumption is incorrect. Plug in fixtures are included. 9.1.3/9.1.4 address both hard wired and plug in fixtures. You must include all lighting.

Since your plug in fixtures are shown on the drawings (i.e. they have been designed), you can claim savings against the baseline. They baseline in a hotel guest room is clearly spelled out in Table 9.6.1 at 1.1 W/sf. The proposed is as designed since it has all been designed.

This gets more difficult in multi-family residential since that is not directly covered by 90.1 but that does not apply to your situation.

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Thomas Leary Executive Vice President, JDB Engineering, Inc. Jul 21 2016 Guest 5 Thumbs Up

Marcus, I agree with you on how the modeling should be done, baseline equals allowable LPDLighting power density (LPD) is the amount of electric lighting, usually measured in watts per square foot, being used to illuminate a given space. from ASHRAE while the proposed equals both the hard wired and plug in fixtures as designed. This is the only fair and honest method, no gamesmanship, and this is what I directed our Junior HVAC and Electrical Engineers to do. However, our electrical engineer pointed out to me that Table 3.1.b says to follow 9.1.3 and 9.1.4 which if you follow the definitions used in these sections does exclude plug-in fixtures, see the following definitions from ASHRAE:
installed interior lighting power: the power in watts of all permanently installed general, task, and furniture lighting systems and luminaires.
permanently installed: equipment that is fixed in place and is not portable or movable.
I think this might be why so many suggest to model the plug in fixtures as a process load in both models. My problem with this is that it would unfairly and incorrectly show a savings in the model by artificially inflating the base buildingThe base building includes elements such as the structure, envelope, and building-level mechanical systems, such as central HVAC, etc. model energy use. This assumes the proposed hardwired lighting is still compared to the baseline LPD with the plug load simply added to both baseline and proposed.
We currently have it modeled as both you and I agree it should be; I simply want to make sure it is correct so it is not questioned when it is reviewed.

Also, is my electrical engineer correct when he says a fixture needs to be modeled based on what the lamp holder is capable of rather than the lamp wattage designed. See ASHRAE 90.1 9.1.4.a: The wattage of incandescent or tungsten-halogen luminaires with medium screw base sockets and not containing permanently installed ballasts shall be the maximum labeled wattage of the luminaire.
What happens here is several large spaces with LED fixtures will actually use half the LPD based on the lamps specified but when modeled at 100 watts per fixture exceed the LPD substantially, doesn't seem right to me. The only reason the lamp holder is rated higher is its more cost effective for the manufacturer to use the standard base rather than a custom base.

I look forward to your response.

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Marcus Sheffer LEED Fellow, 7group Jul 21 2016 LEEDuser Expert 61838 Thumbs Up

I see his point. LEED has always required projects to include all of the lighting as lighting, not process. Your approach would be considered conservative based on the definitions so it should not be questioned by the reviewer.

Your electrical engineer is correct. It says to model the max wattage of the fixture. This is to prevent backsliding from a lower wattage bulb to a higher wattage bulb over the course of operations. So if you are using screw in LEDs and want to claim the savings associated with them the project needs to develop a plan that ensures that there will not be backsliding. Typically this is in the form of a letter from the owner pledging to use certain wattage bulbs. This should not be hard for a hotel and has been accepted by the reviewers for many projects.

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Haojie Wang Energy Modeler KJWW Engineering
Jul 19 2016
Guest
326 Thumbs Up

3 buildings in the same site?

We are looking to certify 3 same buildings. The buildings are exactly the same except the orientation. Can we put the 3 buildings under one LEED application and model them together or we have to use campus approach? Thanks

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Marcus Sheffer LEED Fellow, 7group Jul 19 2016 LEEDuser Expert 61838 Thumbs Up

Are the building connected or completely separate?

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Haojie Wang Energy Modeler, KJWW Engineering Jul 21 2016 Guest 326 Thumbs Up

The buildings are completely separated. They only share the same parking lot.

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Marcus Sheffer LEED Fellow, 7group Jul 21 2016 LEEDuser Expert 61838 Thumbs Up

Sounds like you need to apply the campus guidelines.

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Muzamil Rafique
Jul 18 2016
Guest
112 Thumbs Up

Modeling Software Changing

Project Location: Pakistan

Hello Marcus,

I have question regarding the energy simulation software. Can we change the simulation software at any review stage.However two reviews are completed and previous simulation done on any software.

Thank you in advance.

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Marcus Sheffer LEED Fellow, 7group Jul 19 2016 LEEDuser Expert 61838 Thumbs Up

You can. It is generally not a good idea to do so however because it opens up the entire model to review again. As the reviewer identifies issues with the models those issues are already reviewed and unless you make changes they con't be reviewed again. With a new model you would be starting from step one. I would only do this is the modeler is certain they can get it 100% right in one review phase since this is all you get in an appeal.

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Phil Stafa Sustainability Coordinator Korda/Nemeth Engineering, Inc.
Jul 15 2016
LEEDuser Member
9 Thumbs Up

Exception G3.1.1.c and zones with minimum air changes

Hello:

I have a question related to exception G3.1.1.c which states that a separate single System 3 should be used for zones with pressurization relationships or minimum circulation rates. I have a 3 story mixed use healthcare facility with offices spaces, exam rooms, treatment rooms, research spaces, and a surgical and pre/post suite. My proposed system is chilled water and hot water VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. AHUs. My baseline system is System 5.

1. For the baseline I was intending to model a System 5 per floor and set the minimums to either 0.4 CFM/ft2 or whatever minimum air change rate is required by ASHRAE 170. I do not believe exception G3.1.1.c would be appropriate for this building because multiple zones (about 50%) have minimum circulation rates or pressurization requirements. Does this seem to be an appropriate interpretation of this exception?

2. On the first floor of my building I have a surgical and pre/post suite served by 2 different AHUs. The AHU serving the surgical suite has return terminal boxes on all of the zones whereas the AHU serving the pre/post suite does not have return terminal boxes. I was intending to model the surgical area as a separate System 5 (same zoning as proposed) and the rest of the floor as another System 5. Once again I'm not sure if this would be justifiable so any input is appreciated.

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Marcus Sheffer LEED Fellow, 7group Jul 19 2016 LEEDuser Expert 61838 Thumbs Up

You must model the G3.1.1 exceptions if they apply.

1. Exception c is only applied to spaces in the building that meet this criteria. Typically a surgical suite meets this criteria.

2. See 1. You can't model a separate system 5. You can only apply one of the exceptions. If they apply you must apply them.

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Phil Stafa Sustainability Coordinator Korda/Nemeth Engineering, Inc.
Jul 15 2016
LEEDuser Member
9 Thumbs Up

Unfinished Spaces Baseline and Proposed System

Project Location: United States

Hello:

I have a 3 story mixed use healthcare facility with offices, exam rooms, treatment rooms, research areas, and a surgical suite. Each floor has some unfinished shelled spaces (total is less than 40%). I understand that the unfinished spaces need to be held neutral and modeled the same in the baseline and proposed. My baseline system is System 5 with a rooftop unit per floor.

My proposed HVAC system is chilled water and hot water VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. AHUs. The shelled spaces have ducts and hot water piping capped in the shelled space for future connection when the spaces are built out.

My question relates to how to model the proposed and baseline shelled spaces. For the proposed I was going to model them as a finished design with each shelled space on its respective AHU. For the baseline I was going to model the shelled spaces as one packaged AHU with VAV reheat per zone with the same parameters as the proposed (flow minimums, setpointsSetpoints are normal operating ranges for building systems and indoor environmental quality. When the building systems are outside of their normal operating range, action is taken by the building operator or automation system., etc.). Would this be an appropriate way to model the unfinished spaces? Or should I model the proposed the same as the baseline (packaged AHU with VAV reheat with all parameters as indicated in Appendix G)? Any input is appreciated.

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Marcus Sheffer LEED Fellow, 7group Jul 19 2016 LEEDuser Expert 61838 Thumbs Up

Same as the baseline.

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Panupant Phapant SCG Cement - Building Materials Co.,Ltd.
Jul 14 2016
LEEDuser Member
448 Thumbs Up

Common corridors in residential building

Hi Marcus,

My current project is a 40-story hotel building, which has 35 residential levels and 5 non-residential public-space levels. On the residential levels, the common corridors are conditioned. My queries are:

1.) Are the common corridors on the residential levels considered non-residential spaces?

2.) If the answer to 1.) is yes, the total non-residential floor area will be 80,000 square feet, and these non-residential spaces are on more than 5 floors. How shall the baseline HVAC system for the non-residential spaces be defined? Does the "System 8" come into play in this case?

Thank you very much!

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Marcus Sheffer LEED Fellow, 7group Jul 19 2016 LEEDuser Expert 61838 Thumbs Up

1. I consider them residential as access to the room is their sole purpose.

2. NA

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Dandan Li LEED AP
Jul 15 2016
Guest
2 Thumbs Up

Efficiency of the chiller

Project Location: Germany

Hello all,

we are going to use ASHRAE 90.1-2010 for our LEED v2009 project in Germany. One problem pops up recently. The cooling system we will use in the project is a split cooling system which uses a compressor to distribute the refrigerant through a piping network to multiple indoor units. You can find the chiller here if you are interested:

http://www.emersonnetworkpower.com/en-CALA/Products/PrecisionCooling/Dat...

The problem is in ASHRAE 90.1-2007, the efficiency of VRF cooling system was not covered in the mandatory provisions for LEED minimum energy performance, but in ASHRAE 2010 the minimum efficiency for VRF air cooled air conditioner of our size is 11.6. The ESEER value of our chiller mentioned above is 3.99. I guess there must be something wrong but I can't figure out where. I did some research, and found out that in Germany the efficiency (ESEER) of this kind of chiller is always around 4 to 6. How can it be that their efficiencies are all much lower than the minimum efficiency required in ASHRAE. Or is this kind of cooling actually not exactly the same as what ASHRAE describes, which means there is no requirement on the efficiency of our cooling system?

Thanks a lot.

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Jean Marais b.i.g. Bechtold DesignBuilder Expert Jul 19 2016 LEEDuser Member 10548 Thumbs Up

1) The german ESEER most likely uses a different rating test proceedure. This is a rating value. It means the equipment is tested in the land at specified operating conditions and the results of those tests are weighted as per the proceedure chosen resulting in a single number rating value. A different rating proceedure will result in a different rating value.
2) A VRF system has nothing to do with a chiller. A chiller produces chilled water. A VRF system has indoor and outdoor units that work (usually) with refridgerant, i.e. something that changes phase from gas to liquid in the cycle.
3) chiller efficiencies are anywhere between 3.2 and 5+ depending on how they are back-cooled and other factors; VRFs differ widely...11 to 16. Again this all depends what kind of rating value and method is used.

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Dandan Li LEED AP Jul 20 2016 Guest 2 Thumbs Up

Hello Jean,

Thanks a lot for the input. Now I get your point. So actually what we have in project is not a VRF system, but a chiller system, which carries water instead of refrigerant. As you already said, chiller efficiencies are between 3.2 and 5+. What we plan to use in the project is a air-cooled chiller with cooling capacity from 340 kW to 1200kW, and also with built-in free cooling section. The efficiency:
ESEER = (EER@100% load × 0.03) + (EER@75% load × 0.33) + (EER@50% load × 0.41) + (EER@25% load × 0.23)=3.99
IEER=(EER@100% load × 0.02) + (EER@75% load × 0.617) + (EER@50% load × 0.238) + (EER@25% load × 0.125)=3.80

Does it meet the minimum requirement (mandatory provisions of ASHRAE) of this LEED credit? When I looked at the TABLE 6.8.1A in ASHRAE 90.1-2010, it seems really difficult for us to meet the requirement...Or did I use the wrong TABLE?

Thanks!

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Ghaith Moufarege Jul 21 2016 LEEDuser Member 9666 Thumbs Up

Hello, I guess there is a problem of units. In the US, efficiency can be expressed in (BTUA unit of energy consumed by or delivered to a building. A Btu is an acronym for British thermal unit and is defined as the amount of energy required to increase the temperature of 1 pound of water by 1 degree Fahrenheit, at normal atmospheric pressure. Energy consumption is expressed in Btu to allow for consumption comparisons among fuels that are measured in different units./h) / W. Whereas in Germany, it's dimensionless, W / W.

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Jean Marais b.i.g. Bechtold DesignBuilder Expert Jul 21 2016 LEEDuser Member 10548 Thumbs Up

Unfortunately, the calculation you made it perhaps good for reference, but it's not as simple as you think. Every EER is a rating condition that depends not only on partload percentage of full load (at the rated full load condition), but also depends on other variables like outdoor and indoor air drybulb temperatures and humidities as well as supply and return water temperatures, volume flow rates, sensible heat ratio (and bypass factors). Don't try to calculate this. Get this from the manufacturer for the rated ARHI or whatever test proceedure aligns with the rating value. If they can't supply this then get the test data and simulate it with a program that is capable to simulate the equipment through the rating tests to deturmine the rating value correctly. Or get someone who knows how to simulate it, as not every building simulation expert knows how to do this.

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Stephanie Mezynski
Jul 13 2016
Guest
3 Thumbs Up

Rennovation with small addition

Project Location: United States

I am working on a project that is 15,00 sqft renovation and 8,000 sqft new construction (addition). For the energy performance pre-req and credits would we assume the whole building was new construction or renovation? Or can we break the energy model into 2 models (one for the addition and one for the renovation)

Or can we choose?

Thanks

S

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Marcus Sheffer LEED Fellow, 7group Jul 19 2016 LEEDuser Expert 61838 Thumbs Up

Model the building as it has been designed. Sounds like one model. The new construction area follows the standard modeling protocols. The renovated area will often have some slight variations. You model the existing (prior to renovation) conditions of the building envelope (Table G3.1-5 Baseline (f)). So your model may have more than one (new and existing) U-valueU-value describes how well a building element conducts heat. It measures the rate of heat transfer through a building element over a given area, under standardized conditions. The greater the U-value, the less efficient the building element is as an insulator. The inverse of (1 divided by) the U-value is the R-value. for roof/walls/windows/etc. If you are retaining any exiting HVAC systems you model them identically in both models.

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R2M Solution Srl R2M Solution Srl
Jul 13 2016
LEEDuser Member
78 Thumbs Up

District heating and cooling

Project Location: Italy

I am going to model a building that is connected with a district heating/cooling system. I’m going to use the simplified option of the document “Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 – Design & Construction” (i.e. the Building Stand-Alone Scenario – the building is treated separately from the DES; all upstream equipmentUpstream equipment consists of all heating or cooling systems, equipment, and controls that are associated with a district energy system but are not part of the project building's thermal connection or do not interface with the district energy system. It includes the central energy plant and all transmission and distribution equipment associated with transporting the thermal energy to the project building and site. is ignored).
Since the system is of the same owner of the building, the energy is not paid by the manager of the building, but by the manager of the district system (and the situation is the same for all the buildings that are connected with the district network). Therefore the cost of the energy that is exchanged between the network and the building is not considered. The management of the system buys natural gas, but I don’t know the efficiency of the systems, which are very complicated and we want to avoid to model them.
I see two possible solutions:
1. I consider standard prices for purchased heated/chilled water for the region.
2. I don’t consider the energy cost, but the primary energy.
Are those solutions acceptable?
In both cases I would consider the same values for the baseline model and the design model.
With Regards
Francesco Passerini

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Marcus Sheffer LEED Fellow, 7group Jul 13 2016 LEEDuser Expert 61838 Thumbs Up

Follow the guidance in DESv2 Section 2.4.2.

Based on that the guidance to your options is neither.

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R2M Solution Srl R2M Solution Srl Jul 14 2016 LEEDuser Member 78 Thumbs Up

Hello, Marcus. Thank you. It seems that I’m misunderstanding something.
I’m considering p. 14 of DESv2.
Units of $/MBTU = Virtual Electric Rate (in $/kWhA kilowatt-hour is a unit of work or energy, measured as 1 kilowatt (1,000 watts) of power expended for 1 hour. One kWh is equivalent to 3,412 Btu.) x 71
If the cost of the electric energy is 0.10 $/kWh then the chilled water cost shall be considered 7.1 $/MBTU, i.e. 7.1/0.293 = 24.23 $/kWh.

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Marcus Sheffer LEED Fellow, 7group Jul 20 2016 LEEDuser Expert 61838 Thumbs Up

MBTU = million BTU not thousand BTU

The 71 constant includes the conversion to BTU and the default efficiency of the central plant.

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R2M Solution Srl R2M Solution Srl Jul 20 2016 LEEDuser Member 78 Thumbs Up

Therefore the cost shall be divided by 1000: 0.024 $/kWhA kilowatt-hour is a unit of work or energy, measured as 1 kilowatt (1,000 watts) of power expended for 1 hour. One kWh is equivalent to 3,412 Btu..
Thank you, Marcus.

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Charalampos Giannikopoulos Senior Sustainability Consultant DCarbon
Jul 11 2016
LEEDuser Member
1053 Thumbs Up

Exterior Lighting – Table 1.4.3B

The last section of Table 1.4.3B asks for (i) the “Total Exterior Lighting Power Calculated Above (Watts)” and (ii) the “Total Exterior Lighting Power Modeled (Watts)”. Isn’t the second input supposed to be the same as the first one? Why is the second input asked?

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Marcus Sheffer LEED Fellow, 7group Jul 11 2016 LEEDuser Expert 61838 Thumbs Up

Yes they are supposed to be the same.

The second one is there to confirm what has been modeled as opposed to what has been calculated. It is there to serve as a double check with the models.

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Charalampos Giannikopoulos Senior Sustainability Consultant, DCarbon Jul 11 2016 LEEDuser Member 1053 Thumbs Up

Thanks Marcus. We were simply asked by the reviewer to complete both and was wondering whether we were missing something.

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Marcus Sheffer LEED Fellow, 7group Jul 11 2016 LEEDuser Expert 61838 Thumbs Up

Seems a bit picky to me but it is an easy comment to reply to.

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Addisu Lemlem Project Engineer
Jul 07 2016
Guest
4 Thumbs Up

Dining facility overall area with or without walk-in coolers

Project Location: United States

Thanks Marcus, I just saw your response below.
Follow up question, does a kitchen with higher sensible & latent load qualify for exception b.

Thanks,

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Marcus Sheffer LEED Fellow, 7group Jul 11 2016 LEEDuser Expert 61838 Thumbs Up

It probably does assuming we are talking about a commercial kitchen.

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Cynthia Quinn Principal Ecological Environments, LLC
Jul 06 2016
LEEDuser Member
17 Thumbs Up

California Projects using Title 24-2013

Project Location: United States

To comply with California codes we had to show compliance with Title 24-2013. This required us to use the proprietary program Energy Pro 6. Energy Pro 6 only models against Title 24-2013, and Ashrae 90.1-2010. v2009 requires either Title 24-2005 or ASHRAE 90.1-2007. Unfortunately there is no way to model these codes under Energy Pro 6. We would have to go back to Energy Pro-5 for ASHRAE 90.1-2007, which would require us to build a whole new model (There is no way to save back the model in energy pro). This would be very lengthy and time consuming to create a whole new model.

My question is can we pursue the v4 credit as an alternate compliance path, which allows Title 24-1013, but still use point thresholds comparative to those in the v2009?

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Marcus Sheffer LEED Fellow, 7group Jul 07 2016 LEEDuser Expert 61838 Thumbs Up

Title 24 2013 has been granted equivalency with 90.1-2010 - http://www.usgbc.org/content/10419

There is also an adjusted point threshold for LEED 2009 projects when applying these standards - http://www.usgbc.org/resources/ashrae-901-2010-adjusted-point-scale-leed...

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Addisu Lemlem Project Engineer
Jul 06 2016
Guest
4 Thumbs Up

Dining facility overall area with or without walk-in coolers

Project Location: United States

To generate baseline for HVAC systems, the building total SF is 28000 including walk-in coolers and an outside mechanical room. My question is,
Can I model the walk-in cooler separate? Can I assume the mechanical room separate as system 9 ,and model the rest of the space dining, office, and kitchen combined (<25000 SF) as system type 4?

Thanks in Advance

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Marcus Sheffer LEED Fellow, 7group Jul 07 2016 LEEDuser Expert 61838 Thumbs Up

You can model other HVAC systems if any of the exceptions to G3.1.1 (included those added by Addendum like a heating only space) apply to the predominant condition in the building. When doing so you subtract the area of the spaces where the exception applies and then enter Table G3.1.1A. What you propose sounds like it aligns with what is acceptable.

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Vassil Vassilev Manager Termoservice OOD
Jul 04 2016
LEEDuser Member
320 Thumbs Up

Baseline System 9 fan details

Project Location: Bulgaria

Greetings,
We have zones in our project which are addressed to system 9 (heating only). The heating source is purchased heat, which is to be applied also in the Baseline.
The proposed system however is fully ducted and has an energy recovery device. When it comes to fan power, we believe that we should apply the pressure dropPressure drop is a decrease in pressure from one point in a pipe or tube to another point due to a restriction or length or diameter of the pipe or tube (resistance to flow). adjustment as per table 6.5.3.1.1.B. The software we are using (TRACE 700) has an entry option addressing this table and calculates this adjustment automatically.
Please advise if by applying this approach we could have enter in some miss-compliance or objection from reviewer’s point of view.
Thanks.

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Marcus Sheffer LEED Fellow, 7group Jul 05 2016 LEEDuser Expert 61838 Thumbs Up

I think you can apply the fully ducted return PDA. The one for energy recovery can only be applied in the baseline if the baseline system is required to have one in accordance with 6.5.6.

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Kristina Bach Sustainability Specialist HGA
Jul 01 2016
LEEDuser Member
2048 Thumbs Up

Threshold Error: Minimum Energy Performance Calculator v2009

Our LEED-NC v2009 project (which has the v06 EAp2/EAc1 LEED Credit Form) is attempting to utilize the new required excel calculator and following Option 1 (http://www.usgbc.org/resources/minimum-energy-performance-calculator-v2009 ---- Published on 07-Jan-2016). However, it appears to us that the calculator is not calculating the credit thresholds properly for the v2009 systems.

When we put the project in as 100% new construction, the minimum threshold for EAp2 on the Summary Tab is listed as 5% rather than 10%. While not an issue for that easy example as you can extrapolate by doubling the number, it appears to be a much bigger issue for our project which is a mix of new + renovation...

As an example: If you look at the background calculation [ (5 x % New) + (3 x % Reno) = (Min % for EAp2) ] and were to adjust those numbers to the correct minimums (10 New /// 5 Reno), you can sometimes end up with very different numbers. A 72% New + 28% Reno building in the calculator is showing a minimum reduction of 4% (4.44% calculated by hand). If you followed the logic of doubling the Summary Tab values, that would lead you to an 8% minimum for EAp2. However, changing the percentages in the calculation shows that the project needs a 9% reduction minimum for EAp2 (8.76% calculated).

Marcus, do you know if this is a known error/issue that USGBC is working on? Any idea how reviewers will be handling this current calculation issue/how they will be assessing point thresholds for mixed New/Reno projects? If it is a known issue, have you heard anything as to when a fix might come out now that this calculator is required for v2009 projects using v06 forms?

Finally, is there any guidance on how project teams should complete the v06 EAc1 Form in this case (since the point thresholds on the form will not update based on the breakdown of new vs. reno)? I am assuming that we should put in our actual percentage improvement in the form itself, fill out the special circumstances section with a note regarding the breakdown between new + reno and point-threshold adjustment, and then in the Threshold section we should select the threshold based on the points the calculator indicates that we should achieve NOT based on what the actual threshold is (i.e. if the calculator indicates we should get 7 points, we should pick the 20% New / 16% Reno option even if our percentage is lower than that).

Thank you!

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Marcus Sheffer LEED Fellow, 7group Jul 01 2016 LEEDuser Expert 61838 Thumbs Up

Someone from GBCIThe Green Building Certification Institute (GBCI) manages Leadership in Energy and Environmental Design (LEED) building certification and professional accreditation processes. It was established in 2008 with support from the U.S. Green Building Council (USGBC). hopefully chimes in on this one.

There are v07 forms out. Not sure if they fixed these issues. The latest calculator is from mid-May 2016 - http://www.usgbc.org/resources/minimum-energy-performance-calculator-v2009

We have shared a number of issues with the new forms/calculators so I hope someone is fixing them.

Your approach should work. Make sure to let the reviewer know if you are having such issues.

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André Harms Ecolution Consulting
Jul 01 2016
LEEDuser Member
166 Thumbs Up

Vestibules - CIR 10426 - Interpretation

Project Location: South Africa

The CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide 10426 (http://www.usgbc.org/content/10426) creates the impression that in locations where the local code does not require vestibules they are not mandatory, if a "a narrative explaining how infiltration and exfiltrationExfiltration is air leakage through cracks and interstices and through the ceilings, floors, and walls. of air through building entries is addressed in the design" is provided and the defined energy penalty is applied to the modelled energy savings.

Is this interpretation correct?

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Marcus Sheffer LEED Fellow, 7group Jul 01 2016 LEEDuser Expert 61838 Thumbs Up

That is what I read.

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Muzammal Abbas LEED AP (BD+C) MEP Engineer Pakistan Green Building Council
Jun 29 2016
Guest
4 Thumbs Up

Energy Modeling

Project Location: Pakistan

Hi everyone,

I am doing energy modeling for my project in Pakistan and i want to need some clarification and help from seniors:

1) Is it true that for baseline and proposed case HVAC system should be different for energy modeling, e.g In my case for baseline is Type-6 Packaged roof top VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. but for design case on site there is Air cooled Chiller which have some additional components and aspects as compare to baseline Type-6 Packaged roof top VAV due to which simulation output saving is gong to -ve,
2) What we will be do in case of industrial project to show percentage saving because due to same process load in baseline and design case saving is difficult to achieve even for prerequisite.
3) Ventilation & Exhaust fan load is process or not.

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Marcus Sheffer LEED Fellow, 7group Jun 29 2016 LEEDuser Expert 61838 Thumbs Up

1. The Proposed is as designed. The Baseline is according to Appendix G. So it is often a different system.
2. Find savings within the process load and submit it as an exceptional calculation.
3. If these fans are independently operated from the HVAC system they are process. If they operate in conjunction with the HVAC system they are not process.

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Charalampos Giannikopoulos Senior Sustainability Consultant DCarbon
Jun 28 2016
LEEDuser Member
1053 Thumbs Up

Baseline system selection

Project Location: Greece

For a project that is less than 150,000 ft2 and has 6 floors of which 1 (the basement) is unconditioned would System 6 still be eligible for the project and not System 8? In other words, with regard to the amount of floors (at system selection) do only conditioned floors play a role? Thank you in advance.

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Marcus Sheffer LEED Fellow, 7group Jun 28 2016 LEEDuser Expert 61838 Thumbs Up

Yes only conditioned floors count. If a floor has any conditioned space (even if it is mostly unconditioned) then it counts as a floor.

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Charalampos Giannikopoulos Senior Sustainability Consultant, DCarbon Jun 28 2016 LEEDuser Member 1053 Thumbs Up

Thank you Marcus. However we are experiencing the following situation after a review: The building area is approximately 115,000 ft2, which is between 25,000 ft2 and 150,000 ft2 and has 5 conditioned floors + 1 basement. It is noted that the basement of the building is unconditioned and not conditioned as perceived by the reviewer who requested to use System 8 instead of System 6 already used.

However, the basement was set as “conditioned” in the modeling software eQuest because the software cannot simulate a building with an unconditioned floor without an assigned HVAC system. To this, and although the floor was set as “conditioned”, whereas it is not, no thermostat schedules were set neither for cooling nor for heating so that no corresponding loads were to be calculated.

Alternatively, we could set the basement as “unconditioned” and assign it to one of the above-grade floors HVAC systems in an effort to avoid the “error” message when attempting eQuest simulation. Do you have any idea of the approach we should make (before proceeding with the review response) since we think that the reviewer might have misinterpreted our project conditions?

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Marcus Sheffer LEED Fellow, 7group Jun 29 2016 LEEDuser Expert 61838 Thumbs Up

The alternative is what you should do in the model. Just create the basement as a zone on a system that is unconditioned.

As far as the reviewer response I would send a project team inquiry to the reviewer explaining the situation and ask for further guidance before having to make such a big change to the baseline model. You can send this inquiry here - http://www.usgbc.org/contactus

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April Wang
Jun 28 2016
Guest
8 Thumbs Up

Mechanical systems designed but not installed

Hello all,

I am working on a project where a few of the AHUs and FCUs are defined but scheduled to be installed later in the future - phase II. When simulating the energy performance for LEED, should I include these systems OR not include them and have the spaces left as unconditioned. Would including them be a problem for fundamental commissioning since they will not actually be installed?

Thanks in advance.

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Marcus Sheffer LEED Fellow, 7group Jun 28 2016 LEEDuser Expert 61838 Thumbs Up

Include them in the model. If they have been designed you can include them. If they are not designed then the alternative is to model the space with a system identical to the baseline system, not as unconditioned.

I think you only have to commission what is in the project scope of work.

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SI CHEN
Jun 24 2016
Guest
49 Thumbs Up

IES ApacheHVAC - Proposed system for VRF

Hi All,

I am modelling a VRF system using ApacheHVAC in IES. But have no idea which prototype to choose.

Has anybody have relevant experience?

The VRF is designed as one outdoor units connected to a few inner units.

Shall I use PTAC or DOAS? or any other suggestions? Many thanks!

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Mark Lund Mechanical Discipline Specialist, Bergmann Associates Jun 24 2016 Guest 6 Thumbs Up

We have successfully used System 4, Packaged Rooftop Heat PumpA type of heating and/or cooling equipment that draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside. Heat pumps are vapor-compression refrigeration systems whose indoor/outdoor coils are used reversibly as condensers or evaporators, depending on the need for heating or cooling. In the 2003 CBECS, specific information was collected on whether the heat pump system was a packaged unit, residential-type split system, or individual room heat pump, and whether the heat pump was air source, ground source, or water source. as the Baseline for a VRF Proposed system many times.

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Marcus Sheffer LEED Fellow, 7group Jun 24 2016 LEEDuser Expert 61838 Thumbs Up

If IES does not model this system directly you will need to find a published work around and apply it along with a narrative explanation of how you modeled it for your LEED submission. Some of the VRF manufacturers have published work arounds. We have used one from the Energy Trust of Oregon on projects in the past.

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SI CHEN Jun 24 2016 Guest 49 Thumbs Up

Hi Mark,

Many thanks for your reply.

Yes, I also used system 4 for the baseline system. But I do not know which prototype system I should use in the proposed model....Did you use the prototype system? Thanks.

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