This credit requires that you demonstrate energy savings from HVAC systems and components within your project scope—only systems installed as part of the LEED-CI project, or systems within the LEED boundary. (See more detail on scope below.)
There are two options for achieving this credit, either of which could earn five or ten points for your project.
If your HVAC equipment is fairly conventional, it will likely be listed in the CPG, making Option 1 the easiest approach for five points. More unique or innovative systems may find it better to go with energy modeling.
Is your project located in a LEED-certified building? If so, investigate if the building already has an energy model that you could adapt for this credit, potentially saving cost and enabling you to earn a better score. If not, consider whether your project scope is large or complex enough to warrant using an energy model.
To achieve the first five points in Option 1 the design engineer has to demonstrate that the HVAC system in the space can maintain minimum temperature and humidity ranges that meet ASHRAE-55. This requirement makes those points tricky for projects that do not have humidity control, especially in regions with high humidity. These points also require that you have a mechanical system with efficiency requirements listed in the CPG included in your project. For example, a project with 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. boxes only will not be eligible for the credit, but a project with a split system will.
Option 2 is challenging because for a small CI project the cost of creating an energy model might outweighs the benefit of the potential energy savings achieved from using the model as a design tool. If the base-building has already developed a model, this is often more cost-effective.
A typical HVAC installation in an office fit-out has a minimal scope. Often the base building’s mechanical systems supply the space with heating and cooling and ventilation air. What is left to the fit-out team is the distribution system which includes diffusersIn an HVAC context, diffusers disperse heating, cooling, or ventilation air as it enters a room, ideally preventing uncomfortable direct currents and in many cases, reducing energy costs and improving indoor air quality (IAQ). In light fixtures, diffusers filter and disperse light., VAV boxes, and controls. In LEED Interpretation #10134, issued on 11/1/11, USGBC clarified the level of HVAC equipment that must be installed to make a LEED-CI or LEED-Retail-CI project eligible for EAc1.3, Option 1, as being one of the following:
Another LEED Interpretation, #10135, further clarifies project scope for this credit, noting that "'project scope' refers to all spaces within the LEED project boundary, regardless of whether or not they are included in the project's scope of work. The project can comply with the requirements of the credit as long as all spaces within the 'project scope' satisfy the requirements."
This Interpretation also notes, "Each private office must have its own active controls. Grouping of offices using a single control does not meet the intent of the requirements."
If your space shares a central HVAC plant you need to model the whole building. Consider using energy modeling software, like eQuest, that can separately account for the energy use of the base building separately from your project space by adding additional electricity and gas meters for each space within the model. This is easier and more accurate to model and more likely to be accepted by GBCI reviewers.
Thermostats alone do not meet this definition. LEED Interpretation 10242, issued 10/1/12, clarifies what is expected:
The designer and mechanical engineer review the referenced sections of the Core Performance Guide (CPG).
Decide which option best suits your project. Either way, you can only achieve 5 or 10 points, and nothing in between.
Review sections 1.4, 2.9, and 3.10 in the Advanced Buildings: Core Performance Guide (CPG) to understand the requirements and how they relate to the systems to be installed in the project:
You can only count HVAC components that are within the CI scope of work.
To achieve the first five points in Option 1 the design engineer has to demonstrate that the HVAC system in the space can maintain minimum temperature and humidity ranges that meet ASHRAE-55. This requirement makes those points tricky for projects that do not have humidity control, especially in regions with high humidity.
Review the zoning and controls requirements to see what it will take to achieve these five points (you have to meet all three requirements to earn any points):
Note: If the base building HVAC system can’t be modulated in response to space demand, as with many VAV systems where one zone cannot be the control point of the entire air-handler’s outside air damper minimum position, the design has to meet the following criteria.
A “zone” implies an area with independent control of mechanical HVAC that typically includes its own thermostat and sensors to control air flow or temperature in a space.
Identify each solar exposure and the spaces that correspond to those exposures that have to have a separate control zone. An “exposure” is an external wall that’s included in your project scope. Identify all the external walls in your floor plan, and indicate which direction each faces: north, south, east, or west.
Identify all interior spaces (those without an exterior wall) to be separately zoned.
Identify all private offices and spaces with specialty uses—such as break rooms and conference rooms—to understand how many active controls you’ll need.
Small (<200 ft2) private spaces intended for temporary occupancy like janitor closets, and mechanical rooms can be included as part of a larger zone.
It’s a good idea at this stage to have your mechanical engineer meet with the base building engineer or manager to get detailed information on the possibility of adding controls and outside air intake—and to explore the possibilities of improving the efficiency of the system as a whole. The base building manager can also benefit from becoming familiar with the tenant’s design, which might lead to greater control and system integration.
Find out if it’s feasible to pursue this option. You’ll need to have (or be able to generate) a computer-based energy model running on approved software.
Option 2 is best for projects with unique mechanical systems and energy efficiency strategies that are not included in Advanced Buildings: Core Performance Guide, thus not fitting well with Option 1.
If your project has a larger HVAC scope, one that includes boilers, chillers, or air handling units, it may make sense to develop an energy model to assist in system sizing and selection.
If energy modeling has already been initiated by the base building project team, this is the way to go. If your project is located in a LEED-certified building, it’s likely that an energy model has already been done. If so, check with your building’s owner about accessing the energy model files and results.
It is not easy to achieve 15% or better energy cost savings over current energy codes, such as ASHRAE 90.1-2007, from space heating, cooling, fans, and pumps alone, even though you can factor in HVAC load reductions from envelope improvements and lighting in the equipment energy use calculation.
Developing a simulation model isn’t cheap—in the range of $10,000–$30,000 depending on the complexity of the project—but modeling can provide a favorable payback through design optimization and energy savings.
Many CI projects with limited HVAC design scope find it more cost-effective to pursue Option 1. The usefulness of energy modeling as a design and optimization tool depends upon how wide the project scope is—the more systems that can be influenced in the design process, the better.
The energy modeler should be contracted during early design phase to provide recommendations for a high-performing system and equipment selection along with ideas about potential energy savings, cost estimates, and payback periods.
Pursuing the energy model option can help you document compliance with the energy prerequisite. It can also be useful in applying for financial incentives, which are usually based on a percentage reduction (energy saved) relative to your local code.
Include key HVAC efficiency targets in the Owners Project Requirements (OPR) document for commissioning (see EAp1 and EAc2), with input from the mechanical engineer and other design team members. Use metrics such as number of points to be achieved, HVAC efficiency levels, or HVAC percentage improvement over a baseline. Having those targets in the OPR will help the team develop a design strategy to meet goals for energy efficiency.
Strategize a design direction to meet these goals. Identify ways to reduce energy use by involving the mechanical engineer, architect, lighting designer, owner, and landlord in system design discussions. If applicable, explore passive design techniques within the scope of the interior fit-out.
Encourage an integrated design that includes input from the design team and owners, as well as the architect, lighting designer, mechanical engineer, and others - to align space utilization, window treatments, lighting layout, and thermal zoning to create the most effective design.
Review the Core Performance Guide (CPG) for guidance on load calculations, mechanical equipment selection, and zoning and control requirements. The CPG is a manual that has a format similar to ASHRAE guidelines, so it is best interpreted by a design engineer.
Pay attention to these key points about implementing the requirements of CPG Section 1.4: Mechanical System Design:
Describe the features of your design that can facilitate efficient operation at part-load conditions, and document how your system plans to maintain adequate ventilation air and comfort as required by ASHRAE-55.
If your project is also pursuing IEQc 7.1: Thermal Comfort—Design, the procedures and documentation for that credit will also work for following CPG Section 1.4.
Following Section 2.9: Mechanical Equipment Efficiency, specify all systems within your project scope at performance efficiency equal to or higher than the minimum efficiencies listed in CPG Tables 2.9.1–2.9.6.
Following Section 3.10: Variable Speed Control, specify variable speed drives on pumps and fans greater than 5 hp.
In typical air-conditioned spaces, 20%–30% of energy used is for delivering the conditioned air to the space through ducts and fans. The volume of air depends on the load requirement, which varies with occupancy, latent heat load, and outside weather. Because of variations within all these parameters, delivered air volume should be modulated in occupied spaces with CO2 monitors, VAV boxes, or both to save energy.
The majority of space uses can benefit from variable air volume (VAV) distribution. Some projects, like warehouses and data centers, may not include variable load parameters and so would not save energy with VAVs. In those cases, you can provide a supporting narrative arguing against installing VAV. These less typical projects might benefit from following Option 2.
Review zoning and controls compliance. Make sure that under the proposed mechanical design each interior space with a different exposure is a separate control zone, all appropriate interior spaces have been zoned separately, and that the required demand responsive controls are included.
If they haven’t done so already, have your design engineer develop a cost estimate for the additional zoning and controls required to meet the requirements. Consider whether the benefits in terms of energy savings and improved indoor air quality of the additional controls are worth the cost of installation.
Consider space programming in collaboration with mechanical system zoning. You may want to link similar functions together for mechanical zoning reasons. A floor with an open-plan office space that will only be occupied in the daytime can be controlled by one zone that allows for a reasonable degree of efficiency. On the other hand, if that open-plan office floor also has enclosed conference rooms and private offices, a single zone won’t allow users to adjust temperature and airflow to the enclosed rooms when they are unoccupied, so energy will be wasted.
If your project is installing a Building Management System (BMS), consider scheduling or occupancy sensors that reduce air flow and setback the air-conditioning temperature in unoccupied spaces.
Engage an energy modeler to review the preliminary designs and make recommendations on programming and integration with existing systems. If you still have any options relating to orientation and shading, look at those as well.
Give your energy modeler all relevant, energy-related information on the project, including glazing specifications, wall insulation, roof specifications, building uses on other floors, approximate lighting power use, site plan, and the operating schedule of base-building mechanical systems. Collecting this information will involve the owner, who can connect the energy modeler with the base-building engineer. You can use past energy bills to approximate the energy performance that needs to be input by the energy modeler.
Determine the energy model’s scope. In general, to simulate the performance of building systems an energy model has to include all spaces served by a common HVAC system. However, central HVAC systems often extend beyond the scope of CI projects. For example, if the project scope is a single floor fit-out in a four story building, it’s likely that the building HVAC systems will serve all four floors. The model will simulate the energy use of all four floors, but the CI project can account for only a portion (25% in this case) of the energy use and energy savings from efficiency upgrades.
Start the energy modeling by building the design-case model. Follow Section 11 (Energy Cost Budget) or Appendix G (Performance Rating Method) of ASHRAE 90.1-2007 guidelines for assistance with modeling parameters. Input the existing building’s envelope characteristics, but use project design specifications for energy-using equipment and systems.
Using the Energy Cost Budget method may be more cost effective for your project, as it’s less comprehensive and detailed. However, it does not include savings for energy efficient air distribution systems. If this is where your project is expected to realize significant energy savings, use the Performance Rating Method.
If your project is in a LEED-certified building, a model using the performance rating method may already exist and can be modified to document this credit.
Modifications to the building HVAC system that are to be implemented concurrently with your project should also be included. (These modifications need not be within your project scope.)
Create the baseline model. Two baseline model calculation methods are available; explore both to determine which one is better for your project:
The operational performance of the base building affects the performance of the tenant space. Sometimes the current operator doesn’t know the specifications of the base-building systems that are being modeled, so request as much information as you can, including operations and maintenance manuals that might provide more details.
If pursuing Option 2, and you need to model the whole building because your space shares a central HVAC plant, consider using energy modeling software, like eQuest, that can account for energy use of the base building separately from your project space. This is more likely to be accepted by the reviewers.
Reduced energy loads can translate into lower construction costs because you might be able to get by with smaller equipment; including fans, pumps and auxiliary systems; and less ductwork.
Review the following sections of the Core Performance Guide (CPG) and credit requirements:
Early in design development, engage the energy modeler in reviewing the recommendations for reaching the 15% and 30% energy reduction thresholds. See the LEED-NC energy modeling guidelines for an overview of the energy modeling process and specific guidance on creating the energy model.
Call out the efficiency ratings of selected equipment on mechanical equipment schedules to make sure that the proper model is selected and that the system is installed according to design intent.
Ensure that your project is in compliance with all the prescriptive requirements outlined in the Advanced Buildings: Core Performance Guide, Sections 1.4, 2.9, and 3.10. Complete the prescriptive checklist, and collect equipment cut sheets.
This is an all-or-nothing option: If even one requirement is not met, all five points are lost.
Develop drawings and specifications for the zones and controls.
Ensure that specified HVAC systems and components match or exceed the efficiency requirements of the systems in the final, accepted energy model. Also, ensure that these systems, with their corresponding performance ratings, are included in the appropriate schedules and plans.
Confirm the installation of the selected equipment.
Document the credit requirements on LEED Online, per the option you selected.
For Option 1: Equipment Efficiency & Appropriate Zoning and Controls, document the following:
Monitor equipment energy use over time to confirm that the projected savings are achieved.
Engage a commissioning authority as part of EAc2: Enhanced Commissioning.
Excerpted from LEED 2009 for Commercial Interiors
To achieve increasing levels of energy conservation beyond the prerequisite standard to reduce environmental and economic impacts associated with excessive energy use.
Implement 1 or both of the following strategies:
Reduce design energy cost compared with the energy cost budget for regulated energy components described in the requirements of ANSI/ASHRAE/IESNA Standard 90.1-2007 (with errata but without addenda1). Projects outside the U.S. may use a USGBC approved equivalent standard2.
Demonstrate that HVAC system component performance criteria used for tenant spaceTenant space is the area within the LEED project boundary. For more information on what can and must be in the LEED project boundary see the Minimum Program Requirements (MPRs) and LEED 2009 MPR Supplemental Guidance. Note: tenant space is the same as project space. are 15% better than a system in minimum compliance with ANSI/ASHRAE/IESNA Standard 90.1–2007 (with errata but without addenda1) or USGBC approved equivalent.
Demonstrate that HVAC system component performance criteria used for tenant space are 30% better than a system that is in minimum compliance with ANSI/ASHRAE/IESNA Standard 90.1-2007 (with errata but without addenda1) or USGBC approved equivalent.
Design the HVAC system components to maximize energy performance. Review compliance options for EA Credit 1.3 and determine the most appropriate approach. Option 1 provides a more prescriptive approach to recognizing energy-efficient HVAC design, while Option 2 is performance based.
1. Project teams wishing to use ASHRAE approved addenda for the purposes of this credit may do so at their discretion. Addenda must be appliedconsistently across all LEED credits.
This website discusses the step-by-step process for energy modeling.
A guide for achieving energy efficiency in new commercial buildings, referenced in the LEED energy credits.
Key forms for this credit include the following: Standard 90.1-2007: HVAC Compliance Documentation (PDF), part 1; Standard 90.1-2007: HVAC Compliance Documentation (PDF), part 2; Standard 90.1-2007: HVAC Compliance Documentation (PDF), part 3; Standard 90.1-2007: HVAC Compliance Instructions (PDF).
DOE tools for whole building analyses, including energy simulation, load calculation, renewable energy, retrofit analysis and green buildings tools.
This example narrative of HVAC system serving the tenant spaceTenant space is the area within the LEED project boundary. For more information on what can and must be in the LEED project boundary see the Minimum Program Requirements (MPRs) and LEED 2009 MPR Supplemental Guidance. Note: tenant space is the same as project space. and the building level system describes how the zones and controls were determined, and anticipated energy savings.
The full HVAC system plans and specifications shown in this example demonstrate compliance with credit requirements.
These examples of summary load calculations for the tenant spaceTenant space is the area within the LEED project boundary. For more information on what can and must be in the LEED project boundary see the Minimum Program Requirements (MPRs) and LEED 2009 MPR Supplemental Guidance. Note: tenant space is the same as project space. show assumptions and results at full- and part-load, and compliance with ASHRAE-55.
The following links take you to the public, informational versions of the dynamic LEED Online forms for each CI-2009 EA credit. You'll need to fill out the live versions of these forms on LEED
Online for each credit you hope to earn.
Version 4 forms (newest):
Version 3 forms:
These links are posted by LEEDuser with USGBC's permission. USGBC has certain usage restrictions for these forms; for more information, visit LEED Online and click "Sample Forms Download."
Documentation for this credit can be part of a Design Phase submittal.
For an office building project we will be using a PORTABLE AIR CONDITIONER to cool the IT room; the unit has a cooling capacity of 12,000 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. (Reference:
In order to comply with CI EAc1.3, do we need to add or list this equipment?
Could anyone please offer some clarification?
It is HVAC equipment so I think yes.
We are registed for commercial interior rating system , the system installed in our project is vrv system, in order to comply with optimize energy performance EAC1.3 , critical path supply duct pressure loss ,so should i calculate duct pressure losses for all ducted indoor units or only for fresh air indoor units despite that the fresh air unit is connected to vrv system .
Could you be more specific about which Option you are pursuing under this credit and where the item you are referencing is mentioned?
refering to optimize energy performance option 1 - equipment efficiency - it is mentioned in the requirments of this path to comply the advanced building core performance guid sections 1.4,2.9 and 3.10.
for this path mechanical system design calculations must be included, the load , fan sizing , critical path supply duct pressure loss.. so my question is should i calculate critical path supply duct pressure loss for all indoor units or only for fresh air units.
I think it is referring to all of the supply ducts.
I would like to know on how to comply CI EAc1.3 if using base build Chilled Water Fan Coil Units. What is the alternative to verify the efficiency compliance on Core Performance Guide if the chiller's efficiency is not available.
If the chiller's efficiency in not listed in Table 2.9.5 see note b in that table and then see the link at the bottom of the page for more chiller tables.
Thanks Marcus but how about Chilled Water Fan Coil Equipment Efficiencies since these are not covered under Core Performance Guide? Do we really need to collate the Landlord / Base Build systems together with the project's HVAC systems to comply with this credit requirement? Thanks in advance.
Chilled water fan coil units do not really have a rated efficiency. It is the efficiency of the chiller itself that is in CPG 2.9.
Yes it appears that way. The whole system design is what is addressed by sections 1.4 and 2.9.
The project is approximately 3.0 lack Sft which is G+10 floors and going for LEED CI rating. The 9 floors in the project is office space and remaining one floor is dedicated to labs / data centre. For Equipment efficiency credit – prescriptive approach, the project is meeting the advance building code for COP and IPLV of chillers. The project is going for Air-cooled chillers (7 nos) for labs/ data center and water-cooled centri for other floors i.e. office space. Below are the queries related to the same:
1. Due to the constant temperature in labs and data centre, is it recommended to opt for VFD’s in order to meet the requirement for equipment efficiency points? The temp maintained will be around 18 to 20 deg C
2. For Data centre space the project is also going for IRC(In-Row coolers). Does LEED have any specific reference to verify and check the parameters for IRC system w.r.t LEED for CI? Can In-Row Coolers be considered as PAC unit to meet the LEED CI requirements in Advanced Building Code?
3. Is "Zoning Control" applicable for:
a) data center floors
b) labs/ data center without windows(or windows without vision)
c)un-occupied areas in the floor?
1. The equipment efficiency strategies are prescriptive in nature so you just need to do the minimum requirement. Anything beyond that should be evaluated on its merits in the context of your project. As I recall the 3.10 VSD requirements refer to motors.
2. I don't think these systems are covered. If a system is not covered I do not think you can use the prescriptive approach.
3. These guidelines were clearly not written to cover a data center of lab space.
Off the top of my head it appears like you would need to follow the performance path.
Hi, I have a couple of questions regarding EAc1.3
1. Our HVAC design includes VRF systems that are compliant with sections 1.4 and 2.9 of the Core Performance Guide, but those systems don't have variable control of air (required by section 3.10) However, the standard has an exception if the fans motor horsepower are smaller than 5hp which is our case. Is that an allowable exception to be used for submittal review purposes?
2.We are trying to pursue the zoning and controls strategy; is it correct if we use occupancy sensors for independent offices, conference rooms, etc. that turn on and off the units based on occupancy but with no setback and with no demand-controlled ventilation strategies?
Thank you in advance
I can only comment on the second question. There are two LEED Interpretations on this topic (#10242 and #10263). The second requires demand controlled ventilation in conference rooms, but not individual offices. We've successfully appealed this on CI a project with a base building CAV system by pointing out this approach would increase rather than decrease energy, but this only works because the building has not installed variable frequency controls on the 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. drives.
Thank you Michael for your answer, I will check the leed interpretations immediately.
Id really appreciate if anyone can help me with the first question, is it necessary to have variable control of air in a VRF system if the fans motor horsepower are smaller than 5hp? Is that exception a valid path for submittal review purposes?
1. Yes fans smaller than 5 HP do not have to meet this criteria.
Thank you Marcus, that is good news
I've been working in a LEED CI: Retail for a small store in a mall.
I'm wondering to persue the option 1: zoning and controls for the project but i'm not sure if the sales floor of the store should be classed as a special occupancy that requires active controls for OA. Do you have any tips for that?
In case i have a single zone conditioned space that requires no active controls for OA. Would i still be eligible to earn these points?
I would need to check the Reference Guide to be sure but I think that the retail space would be a special occupancy. Since the space has highly variable levels of occupancy (like a conference room), it should have some controls beyond a thermostat. If you installed DCV on the single zone system it would probably qualify.
Thank you Marcus. It was very helpful.
Hi to all:
On regards Option 2, the Reference Guide is clear about the thresholds that must be achieved as HVAC systems annual cost savings, but it is not clear if those savings can be boosted by energy conservation measures as installing additional insulation, reducing LPDLighting power density (LPD) is the amount of electric lighting, usually measured in watts per square foot, being used to illuminate a given space., reducing miscellaneous loads, etc.
We are working on a tenant spaceTenant space is the area within the LEED project boundary. For more information on what can and must be in the LEED project boundary see the Minimum Program Requirements (MPRs) and LEED 2009 MPR Supplemental Guidance. Note: tenant space is the same as project space. where we didn't have any responsibility on the design of the envelope, but the Owner has allowed us to implement enhancements on the existing fenestration and roof insulation which will lead us to improve our HVAC energy savings.
According to the Reference Guide, it is recommended to model in the design case any reduction in the miscellaneous loads if the project is pursuing EAc1.4, which makes us think that the same logic applies to other load vectors as the mentioned above, but there is no statement that clearly indicates it.
Id appreciate your help; and if we can take credit of the envelope enhancements please confirm if the baseline should be either the original building envelope or the 90.1 envelope requirements.
Thanks in advance.
This credit only deals with HVAC energy savings. The other systems are held neutral in both models and the HVAC enhancements are isolated to determine the percent savings. So you do not get any credit for envelop, lighting, or process loads.
Thanks Marcus, but why is it suggested in the Reference Guide to take credit of the EAc1 energy reductions for modeling purposes just only in the proposed design if both cases should be held neutral?
Please be more specific with your Reference Guide citation if you want me to take a closer look.
To me it makes no sense to allow savings from other building systems for this credit which is about the HVAC systems. I am open to being shown my error so please be more specific about what you are seeing (page number, section, etc.) in the Reference Guide.
Hi, for the HVAC Equipment points (5), our project meets the requirements of sections 1.4 and 2.9 of the core performance guide but not 3.10 since the system is constant volume (as most VRF and inverter split unit types are). Does this mean we cannot score any points at all?
Correct, you must meet all three criteria to earn any points.
Thanks Marcus. Our only hope for the full 10 points is via the modelling route then, although 30% HVAC saving is quite challenging.
I want to know that is it mandatory to provide energy modeling for commercial interior project's for LEED submission,
Now my second question is that i am using a HAP 4.8 and eQUEST software for energy modeling but in these there is no option for LEED CI only LEED NC is avalable for base case so what we should do because aur project is LEED CI,
kindly Sir give us the solution of it for LEED CI and if you have a sample project of LEED CI with complete detail for LEED Submission then email
An energy model is not required for CI projects. It may be needed depending upon the option chosen for this credit but it is not required.
We are working for a CI project where the developer has provided a centralized HVAC system. We are following a prescriptive path for the HVAC compliance under EA Cr 1.3. In the LEED form we need to mention the pumps and fan details which should have variable frequency drive under criteria 3.10.
I wanted to know if these details will be only limited to the tenant spaceTenant space is the area within the LEED project boundary. For more information on what can and must be in the LEED project boundary see the Minimum Program Requirements (MPRs) and LEED 2009 MPR Supplemental Guidance. Note: tenant space is the same as project space. or we need to also list down the pump details of the common centralized system.
In general I believe that the only equipment covered is that within the tenant scope of work.
The 5 credits for zoning can be achieved based on the system installed within the tenant scope of works. The 5 points for system efficiency are awarded based on the Landlord base building system, even though it is beyond the "project boundary." There's a LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. on this - check the database for the details.
We have a project with both perimeter and interior offices. Every office has occupancy sensing devices that are connected to VAVs so that the HVAC system can adjust when the office is not occupied. Isn't this normally sufficient for active controls? To achieve this credit, are we also required to provide thermostatic control for each office as well? We are only able to put thermostats in approx. 50% of our offices.
These questions come up for us because of our preliminary design reviewer's comments. For this credit our reviewer has advised:
"1. Perimeter private offices require a separate thermal control for each space paired with an occupant sensing or CO2Carbon dioxide sensing device, which is used to set back the temperature setpoint or airflow to the space when the space is unoccupied. Provide documentation to demonstrate that all perimeter private offices have been provided with active controls that are capable of sensing space use and modulating the HVAC system in response to space demand, such as demand controlled ventilation or occupancy responsive HVAC controls. 2. Interior private offices require a separate thermal control for each space. Provide documentation confirming that a separate thermal control is installed for each interior private office."
So, I don't know if they just didn't see the occupancy sensors on the drawings OR if they are saying that we need to provide something beyond that... By 'thermal control' for the interior private offices are they likely referring to providing a thermostat in each office?
LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. 10263 has the description of control devices now required in each type of space: http://www.usgbc.org/leed-interpretations?keys=10263&=Search
Every private office, both perimeter and interior, will need its own temperature control in order to qualify for this credit. The only argument you might have is if your project was registered before LI 10263 was published, in which case make sure you also look at LI 10242 to make sure you comply with those requirements. (assuming you registered after it was published)
This credit has become very difficult to achieve due to all of the control requirements, but there aren't many other ways for a tenant fit-out to affect energy use of the base building HVAC systems.
I am working on a small building that is pursuing LEED CI. The building is comprised of two tenant spaces, office and restaurant/dining. The office space (pursuing LEED CI) is completely finished and occupied while the restaurant/dining is unfinished shell space. The restaurant/dining area does include Base Building HVAC equipment, plumbing and lighting for permit.
I would like to model the building using the Option 2 Baseline method. However, since the restaurant/dining is unfinished I am unsure how to model this space for lighting. Can I assume ASHRAE 90.1 values per Section 11 or should I use the Base Building lighting power densities which only include emergency lightingEmergency lighting as defined by the Illuminating Engineering Society of North America is lighting designed to supply illumination essential to the safety of life and property in the event of failure of the normal supply.? Your feedback is welcome.
You model it the same as the Baseline allowance.
Marcus, thank you for your response. Now that I read my question, I'm not sure I was clear in which space I had the question. It is the restaurant/dining space that I was unsure of.
If I use Base Building (Core and Shell) lighting it will only include emergency lightingEmergency lighting as defined by the Illuminating Engineering Society of North America is lighting designed to supply illumination essential to the safety of life and property in the event of failure of the normal supply. as the space is not built out. The other option, which I used in the LEED submission is to use the "not to exceed" LPDLighting power density (LPD) is the amount of electric lighting, usually measured in watts per square foot, being used to illuminate a given space. value listed in the Tenant Lease Agreement.
Perhaps it was my answer which was not clear.
Baseline means according to Appendix G/Section 11.
If you have a lighting design or a not to exceed LPDLighting power density (LPD) is the amount of electric lighting, usually measured in watts per square foot, being used to illuminate a given space. in the lease agreement then you can use those values to claim savings. However, for this credit under Option 2 I think you are supposed to hold all of the non-HVAC modeling inputs neutral (i.e. the same) to determine the HVAC percentage only. The procedure is in the Reference Guide.
Hello - We are in the process of certifying an interior fit-up which utilizes a number of small "huddle rooms" which are enclosed spaces roughly the size of a private office, but furnished with occasional/lounge furniture for informal discussion (rather than a more formal conference table/chair setup). ASHRAE, Core Performance, and Local Code do not provide an specifics on how to treat Huddle Rooms w/r/t EAc1.3 Option 1 Zoning and Controls. They have been treated, conditioned, and controlled as open spaces due to their size, and expected utilization/occupancy of 2-4 persons at a time for short periods of time. In other words, they often share zones or controls with nearby spaces.
Our LEED Reviewer has requested that each Huddle Room be classified as a conference room requiring individual controls per room.
Question: Is there a formal LEED interpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. or other document that outlines the exact treatment of Huddle Rooms as they pertain to EAc1.3 Option 1? Has any other project team successfully pursued this credit and NOT provided individual controls for rooms like these?
While I don't have experience with any projects using Huddle Rooms, as an outsider looking in I don't think you will be able to get this without the individual control.
What you have created with the Huddle Room is an enclosed space with a different load profile from the open office outside. Like it or not, these rooms still behave much like a conference room thermally, in that it is a more densely occupied space than the surrounding open office. The fact that they are used sporadically only serves to strengthen the argument that they should be controlled separately from the surrounding area. The intent of the credit is to ensure as much energy savings as possible given the limited impact most CI projects can have on the central HVAC system. Thus the requirement to turn off as much as possible when it isn't in use.
I am not a LEED official, but this is how I would interpret the issue. You can always ask further questions of your reviewer, or try to get them on the phone to plead your case.
They are the same size as offices, so if they were reclassified as offices, could we still pursue the credit, all else being equal?
They will still need separate thermal controls if they are renamed as offices. Check out LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. #10263 to see what constitutes active controls for different types of spaces: http://www.usgbc.org/leed-interpretations?keys=10263&=Search
Thanks Terry. This is one of the most cost prohibitive credits in the LEED Reference Guide.
I am working on a multi-story office fitout for a single tenant, and we received a review comment on our submission regarding EAc1.3 asking us to "provide documentation that all conference rooms have been provided with demand control ventilation PLUS thermostat setback." The reviewer then refers to LI#10242 and LI#10263 for further guidance.
Looking at LI#10242, the Ruling states "...active controls typically regulate the required outdoor air flow for ventilation, such as using demand controlled ventilation with CO2Carbon dioxide sensors in each private office and specialty occupancy space, OR (emphasis added) regulate temperature set point based on occupancy..."
In the subsequent LI#10263, the Ruling gives specific guidance for densely occupied spacesDensely occupied spaces are areas with a design occupant density of 25 people or more per 1,000 square feet (40 square feet or less per person)., requiring "a separate thermal control for each space paired with a CO2 or occupant sensing device, which is used for demand control ventilation AND (emphasis added) to set back the temperature setpoint to the space when the space is unoccupied."
My question is, does the later LI override the former? That difference between OR and AND is a big one, as the newer LI is adding a third requirement for densely occupied spaces (separate thermal zones, CO2-based DCV, AND occupancy sensors to force temperature setback). We have successfully submitted other tenant fitouts under this same rating system using just individual zone temperature sensors and CO2 sensors driving DCV, so to get this comment on our review was a shock. (Just when you think you understand the requirements...)
I'm also not certain how to use a CO2 sensor as an occupancy sensing device, as alluded to in the LI#10263 text. I suppose we could set some limit on CO2, perhaps a little below our limit for returning the damper to thermal control from DCV control, that would initiate temperature setback. That seems a little cumbersome though. We do have occ. sensors for our lights, but unfortunately they do not have the spare contacts required for connection to the HVAC control system.
I'm also not sure I'm on board with temperature setback during "occupied" hours in conference rooms. If we allow the temperature to rise to 80 deg F because the conference room is unoccupied, the next group to come into the room is going to be uncomfortable and the system may not be able to bring the temperature down to occupied setpoint quickly enough. I see this control causing a lot of headaches for building maintenance.
Thanks in advance for your time and advice.
We have just had this credit denied in final review because we do not meet the requirements of LI#10263. A previous project (same tenant, same floor) was registered before LI#10263 but reviewed afterwards - the review comments at that time specifically said that we did not need to incorporate the LI#10263 requirements but would have to for future projects.
My question relates to the requirement for DCV control in our project which has a CAV system. Our occupancy sensors turn off the fan-coil in the room when it is unoccupied which - we believe - results in the maximum energy savings possible. Is there a reason how DCV would contribute to the credit intent of increasing energy conservation in a CAV system? Cutting off fresh air to the conference rooms when unoccupied would simply redirect the air to other spaces without reducing power consumption. Indeed, an (admittedly very, very small) amount of additional energy would be required to modulate the dampers. Should we appeal this?
We received a review comment back, on Energy Modeling report use to document EA cr1.3, that stated the following: "The Proposed design air cooled chiller COP for office is indicated 2.5 does not comply with the requirements of ASHRAE 90.1-2007, Section 18.104.22.168 which requires the minimum efficiency requirement of air cooled chiller per Table 6.8.1.C. This will preclude the project from using Alternate Baseline method"
The reviewer goes on to recommend using the Baseline method of modeling instead. My question is if the design chiller COP used in the model was too low to meet the requirements, couldn't we just simply rerun the model using the min. efficiency COP from Table 6.8.1.C. ...which should generated even better savings? Am I missing something here?
Chiller efficiency is "mandatory" provision (6.4) which specify the minimum for each cooling epuipment. Failing to comply will lead to not meet requirement of credit EAp2 which is a prerequisite.
I am not sure with or have heard of the "alternate baseline method". Also waiting to see other comments.
Sorry, I believe to reviewer meant to say "Alternative" Baseline Method
The project can demonstrate the installed equipment meets the mandatory requirements, I believe the low COP value of 2.5 was entered in error during the modeling. It just concerns me that the reviewer's solution was to change to the "Baseline Method", rather than correct the input data for the model. Is it a case of once you've submitted a design chiller COP, are you stuck with it; so changing the existing model is not an option? Or is it because since the project is just a portion of an existing building, the Baseline Method is more applicable?
You can change the model and simulate again. Simply write the narrative to explain the reviewer about the input mistake. However, please make sure the matching COP with the comissioning data EAp1 and EAc3.
Thanks for your help Jatuwat!
I've found some of the USGBC review comments confusing and I'm not entirely sure they will accept us simply changing the COP number. One of their comments seemed to question if the model was consistent with ASHRAE 90.1.2007 requirements at all.
Unfortunately I do not have a lot of experience with energy modeling; can you recommend any resources that would help me understand them better?
Download the Advance Energy Modeling Guide for LEED from the USGBC web site.
If you are concerned about changing the COP provide additional documentation (product literature perhaps) to verify the correct COP.
Hello. We're trying to decide if pursuing energy modeling under Option 2's Path 1 would be worth the effort. The project is a tenant fit out of the 23rd and 24th floor in one of the two 24 floor attached buildings the central plant serves. The HVAC design adds a few terminal units and one split system to serve a server room in the project scope but no major changes are made to the central plant. I understand that the entire two building complex and the central plant would have to be modeled in both the Baseline and Proposed Cases. The local HVAC modifications' efficiencies are only slightly better than ASHRAE 90.1 prescriptive values. The design does not meet the Option 1 requirements.
Given this, is there a way to estimate if 15% HVAC energy cost improvement is demonstrable or not before the data collection and modeling effort is taken up? It seems like a tall order especially if only two floors of the 48 or so floors are undergoing modest improvements.
Thanks for your attention.
Hi, we have 2 buildings on our site pursuing two separate certifications. One is an office building and the other a data centre (one client). A portion of the office has some of the data centre equipment (command room) and is fed off a central system that serves the main data centre. Electricity for that room is also off the main data centre distribution board. Is it possible to model the energy use of the data centre portion of the office block with the main data centre and exclude it from the office model? (Even though it is housed in the office block)
The reason for doing this would be to simplify the model so that we don't have to try and apportion energy use from different parts of the data centre.
Chilufya, I'm sorry for the slow response—have you figured out a solution to this?
My take would be that this would be very tricky in terms of managing these two projects as separate LEED certifications with overlapping energy models. The onus would be on you to show that you can do this is a way that is robust and makes real sense in terms of LEED.
Would it make any sense to put the data center portion of the office building in the LEED boundary for the data center?
Hi Tristan, thanks for your response. I will suggest that and see how it affects the rest of the credits being targeted.
We have an open office 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. project that is only pursuing the "Appropriate Zoning and Controls" portion of Option 1. I just had a few questions regarding how different space types are handled:
Copy Rooms (> 85 sqft): Do these rooms need their own active control? Are they compliant if the active controls and VAV box are intended for an adjacent conference room, but the copy room simply has a supply diffuser?
Storage Rooms: Similarly, is it sufficient that these rooms simply have a supply diffuser that provides air based upon the active controls in an adjacent private office? Do they need to be zoned separately?
Quiet Zones: We are planning on active controls in these spaces, which serve as a larger "enclosed" office for upwards of eight people. Are active controls necessary here?
Thanks for the help!
I do not think that a very small copy room or storage necessarily needs separate controls. Not sure about the quiet zones, sounds like they probably do.
I have read Interpretation #10134 and 10135, but based on some of the comments below, I would like some additional confirmation. Does new system-level mechanical equipment that serves 60% of the space need to be installed (to pursue item 1 or 2 in #10134), or can this apply to existing systems serving new zone-level equipment (i.e. 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. reheat boxes)? Otherwise item 3 will have to be pursued, meaning that existing equipment will have to meet all relevant criteria.
Steve, you must install air-handlers supplying 60% of the flow or heating/cooling equipmentThe equipment used for cooling room air in a building for human comfort. supplying 60% of heating/cooling capacity to pursue the first two options under Intepretation #10134. If the scope of work for the LEED CI fitout only includes new ducts and 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. boxes, then you have to show that existing or base-building equipment meets the requirements in the CPG.
We are a bit confused as to the meaning of space fan and pump sizing? Could anyone please offer some clarification?
Could you please indicate where these terms have been referenced for context?
It is on the online form, under Equipment Efficiency, under section 1.4-Mechanical System Design Criteria
Which version of the form?
This section of Core Performance deals with designing the mechanical systems. There are a series of steps outlined in this section which must be followed and then documented to demonstrate compliance. What needs to be done is documented in the Core Performance document which you need to have a copy of to be able to demonstrate compliance.
We are looking at Option 1 - Equipment Efficiency under Core Performance Guide
The reason is that all mechanical systems are in the basebuild and we were wondering whether the kW of the tenant spaceTenant space is the area within the LEED project boundary. For more information on what can and must be in the LEED project boundary see the Minimum Program Requirements (MPRs) and LEED 2009 MPR Supplemental Guidance. Note: tenant space is the same as project space. fan and pump sizing should be included or left blank? The system is a chilled ceiling system.
Now I see it. Only those components within the tenant scope of work need to be included. Anything within the base building systems that is already in place does not need to be addressed. This line clearly indicates tenant fan and pump sizing. If the fans and pumps are already there and are not part of the tenant scope of work leave it blank or indicate NA.
Thanks a lot Marcus! Much appreciated! Does the same apply for Table EAc1.3-1 under Criteria 2.9 regarding variable speed control?
I think the same principle applies - if it is not in the tenant scope of work you do not have to demonstrate compliance.
Another one I can´t quite get my head around.
Our client will be the sole tenant in a small commercial building. The owner has provided a VRF system complete with the condensers and evaporators (the space has never been occupied).
Our preliminary review suggests that the system will comply with the ASHRAE and NBI requirements.but if the tenant does nothing more than install proper zone ductwork and controls can they achieve the Equipment Efficiency portion of this credit?
Senior Sustainability Manager
Onsite renewable energy recognized under SSc1 Option 2, Path 11, can add to energy savings if you choose to perform energy modeling under EAc1.3.
If you choose to perform energy modeling, your documentation will serve both EAp2 and EAc1.3.
Reducing lighting power density can reduce energy use for cooling, improving results from the energy modeling.
Reducing lighting energy use can reduce energy use for cooling, improving results from energy modeling.
Reducing equipment energy use can reduce energy use for cooling, improving results from energy modeling.
While not contributing to EAc1.3, enhanced commissioning helps you realize the operational benefits of your energy-efficient design.
Good zoning and controls, and an energy model, all help with ongoing monitoring of energy-using systems to improve performance over time.
This prerequisite establishes minimum airflow requirements for the space; EAc1.3 helps to optimize the delivery of that airflow.
IEQc1 requires additional sensors that improve on the controls used to achieve EAc1.3.
This credit provides an opportunity to further enhance IAQ above the requirements of EAc1.3.
Do you know which LEED credits have the most LEED Interpretations and addenda, and which have none? The Missing Manual does. Check here first to see where you need to update yourself, and share the link with your team.
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