NC-v4 EAp2: Minimum energy performance

  • A high bar, but still achievable

    This prerequisite is a big one, not only because it’s required for all projects, but also because it feeds directly into EAc2: Optimize Energy Performance, where about a fifth of the total available points in LEED are at stake.

    From the beginning, teams should recognize that the baseline requirements are fairly stringent. Some measures that may have previously contributed to design-case efficiency are now being required just to meet this prerequisite.

    Key updates with ASHRAE 90.1

    ASHRAE 90.1-2010 has introduced a number of new requirements compared to the 2007 standard, including increased efficiencies requirements for envelope, HVAC equipment and lighting; enhanced interior lighting control requirements (occupancy sensors, light level reduction and daylight controls); new exterior lighting and parking garage lighting control requirements; and new automatic shut-off requirements for 50% of receptacles in offices and computer classrooms.

    With these changes, however, comes a helpful update to the prerequisite documentation that will make the review process go more smoothly for both project teams and 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). reviewers. An updated Energy Performance Calculator is required documentation for your LEED submittal.

    It performs a series of self-checks in the background to flag potential issues, allows the energy modeler to do a step-by-step quality assurance review, and maybe most importantly helps the reviewer to better understand the model, all of which should significantly reduce the quantity of back-and-forth comments and responses required between the modeler and GBCI reviewer. Read more about the calculator, including an overview of how to use it, here on LEEDuser.

    What’s New in LEED v4

    • ASHRAE 90.1-2007 has been updated to ASHRAE 90.1-2010.
    • Process energy no longer has to make up 25% of the overall building energy for your baseline and proposed simulation models.
    • USGBC now requires you to achieve prerequisite compliance without accounting for the cost of generating renewable energy onsite.
    • For data centers, USGBC requires that building power and cooling infrastructure provides 2% of the required 5% energy cost reductions.
    • For Option 2, LEED now includes a prerequisite that the standard for compliance uses the 50% savings version of the AEDG instead of the 30% savings version of the AEDG. This represents an expected savings of 50% over ASHRAE 90.1–2004.
    • To achieve the prerequisites for Options 2 and 3, your project must follow ASHRAE 90.1–2010 mandatory and prescriptive requirements.

    FAQs

    Our proposed design has insulation R-values that are below those prescribed by ASHRAE 90.1-2010. Can we still meet the prerequisite?

    Yes, the R-value of the building envelope is not mandatory. You can install lower R-values. You are only required to meet the mandatory provisions and earn the minimum percent savings.

    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, but there is a greater burden of proof on the project team to demonstrate savings in process energy. As a default, process energy should be modeled the same in both baseline and design case.

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

    No. The energy cost offset from onsite renewable energy sources can no longer be used to earn the prerequisite. Additionally, it is usually more cost-effective to invest in energy savings in the building.

     

  • EA Prerequisite 2: Minimum energy performance

    Intent

    To reduce the environmental and economic harms of excessive energy use by achieving a minimum level of energy efficiency for the building and its systems.

    Requirements

    Option 1. Whole-building energy simulation

    Demonstrate an improvement of 5% for new construction, 3% for major renovations, or 2% for core and shell projects in the proposed building performance rating compared with the baseline building performanceThe annual energy cost for a building design, used as a baseline for comparison with above-standard design. rating. Calculate the baseline building performance according to ANSI/ASHRAE/IESNA Standard 90.1–2010, Appendix G, with errata (or a USGBC-approved equivalent standard for projects outside the U.S.), using a simulation model.

    Projects must meet the minimum percentage savings before taking credit for renewable energy systems.

    The proposed design must meet the following criteria:

    Document the energy modeling input assumptions for unregulated loads. Unregulated loads should be modeled accurately to reflect the actual expected energy consumption of the building.

    If unregulated loads are not identical for both the baseline and the proposed building performance rating, and the simulation program cannot accurately model the savings, follow the exceptional calculation method (ANSI/ASHRAE/IESNA Standard 90.1–2010, G2.5). Alternatively, use the COMNET Modeling Guidelines and Procedures to document measures that reduce unregulated loads.

    OR

    Option 2. Prescriptive compliance: ASHRAE 50% Advanced Energy Design Guide

    Comply with the mandatory and prescriptive provisions of ANSI/ASHRAE/IESNA Standard 90.1–2010, with errata (or a USGBC-approved equivalent standard for projects outside the U.S.).

    Comply with the HVAC and service water heating requirements, including equipment efficiency, economizers, ventilation, and ducts and dampers, in Chapter 4, Design Strategies and Recommendations by 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., for the appropriate ASHRAE 50% Advanced Energy Design Guide and climate zone:

    • ASHRAE 50% Advanced Energy Design Guide for Small to Medium Office Buildings, for office buildings smaller than 100,000 square feet (9 290 square meters);
    • ASHRAE 50% Advanced Energy Design Guide for Medium to Large Box Retail Buildings, for retail buildings with 20,000 to 100,000 square feet (1 860 to 9 290 square meters);
    • ASHRAE 50% Advanced Energy Design Guide for K–12 School Buildings; or
    • ASHRAE 50% Advanced Energy Design Guide for Large Hospitals. Over 100,000 square feet (9 290 square meters)

    For projects outside the U.S., consult ASHRAE/ASHRAE/IESNA Standard 90.1–2010, Appendixes B and D, to determine the appropriate climate zone.

    OR

    Option 3. Prescriptive compliance: Advanced BuildingsTM Core PerformanceTM Guide

    Comply with the mandatory and prescriptive provisions of ANSI/ASHRAE/IESNA Standard 90.1-2010, with errata (or USGBC approved equivalent standard for projects outside the U.S.).

    Comply with Section 1: Design Process Strategies, Section 2: Core Performance Requirements, and the following three strategies from Section 3: Enhanced Performance Strategies, as applicable. Where standards conflict, follow the more stringent of the two. For projects outside the U.S., consult ANSI/ASHRAE/IESNA Standard 90.1-2010, Appendixes B and D, to determine the appropriate climate zone.

    3.5 Supply Air Temperature Reset (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.)

    3.9 Premium Economizer Performance

    3.10 Variable Speed Control

    To be eligible for Option 3, the project must be less than 100,000 square feet (9 290 square meters).

    Note: Healthcare, Warehouse or Laboratory projects are ineligible for Option 3.

    Pilot ACPs Available

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

    EApc92: Advanced Buildings™ New Construction Guide
    EApc95: Alternative Energy Performance Metric
    EApc107: Energy Performance Metering Path

    Alternative Compliance Paths (ACPs)

    Canada ACP - NECB

    Projects in Canada may instead demonstrate a percentage improvement in the proposed building performance rating compared with the baseline according to the National Energy Code for Buildings (NECB) 2011. The same percentage cost improvement in energy performance is required to meet the Prerequisite, and the same points for cost percentage improvement in energy performance are applicable for the Credit.

    The following conditions (where applicable) must be met. Note that unless otherwise noted, CanQUEST (the Canadian energy modelling software based on eQUEST that performs NECB 2011 compliance runs) does not implement many of these conditions correctly and would require corresponding modifications to the Reference case.

    1. Comply with mandatory requirements of ASHRAE 90.1-2010
    2. ASHRAE 90.1-2010 mandatory requirements must be met, in addition to the performance path limitations referenced in the NECB 2011 Sections 3.4.1.2, 5.4.1.2 and 6.4.1.2. In cases where ASHRAE and the NECBC reference requirements concerning the same item, the more stringent requirement shall be adhered to.

      The following exceptions apply:

    • ASHRAE 90.1-2010 mandatory items 6.4.3.9, 9.4.1.2b, 9.4.1.4, 9.4.1.5, 9.4.3

  • Apply fenestration area convention similar to ASHRAE 90.1-2010
  • Maintain the same FWR (as defined by NECB, including doors) for the Reference as exists in the Proposed Design, up to the prescribed maximum. If the Proposed Design’s FWR exceeds the prescribed FWR, scale down the fenestrations in the Reference case accordingly.

  • Apply skylight area convention similar to ASHRAE 90.1-2010
  • Maintain the same SRR for the Reference as exists in the Proposed Design, up to the prescribed 5% maximum. If the Proposed Design’s SRR exceeds 5%, scale down the skylights in the Reference case accordingly.

  • Model proposed and reference outside air similar to ASHRAE 90.1-2010
  • Proposed and reference (baseline) outside air rates shall be modeled as per ASHRAE 90.1 – 2010 (G3.1.2.6).

  • Apply ASHRAE kitchen exhaust demand ventilation requirements
  • Provide for the same demand ventilation requirements as described in ASHRAE Appendix G3.1.1.d.

  • Apply ASHRAE’s chiller heat recovery requirements
  • Provide for the same chiller heat recovery requirements as applies to ASHRAE.

  • Apply supply air temperature reset controlled based on warmest zone
  • Reset the minimum supply air temperature to satisfy the cooling requirements of the warmest zone, as stipulated in NECB Section 5.2.8.8. Note that this control setting is already corrected in CanQUEST for the Reference case.

  • Account for uninsulated structural penetrations if they exceed 2% of net wall area
  • The 2% allowance may be applied, but based on the net opaque wall area, not the entire building envelope area.

  • Follow ASHRAE/LEED rules for renovations to existing buildings
  • Model existing components consistent with ASHRAE and LEED provisions.

  • Account for all anticipated energy use in building
  • Fully account for all energy end-uses in the energy performance modelling.

  • DES Systems are to be modeled according to Option 1, Path 1 or Option 1, Path 2 as indicated in the LEED v4 Reference Guide
  • The following exceptions apply:

    • Option 1, Path 1 - Do not apply ASHRAE 90.1-2010 requirements for purchased heating and cooling. Under this ACP, purchased heating and cooling (as applicable) are modeled as cost-neutral in the baseline and proposed case. Local rates for purchased heating (fossil fuel based) and cooling are used to establish the purchased heating and cooling costs. The energy model's scope accounts for only downstream equipmentThe heating and cooling systems, equipment, and controls located in the project building or on the project site and associated with transporting the thermal energy of the district energy system (DES) into heated and cooled spaces. Downstream equipment includes the thermal connection or interface with the DES, secondary distribution systems in the building, and terminal units. Drift water droplets carried from a cooling tower or evaporative condenser by a stream of air passing through the system. Drift eliminators capture these droplets and return them to the reservoir at the bottom of the cooling tower or evaporative condenser for recirculation., plus purchased heating and cooling. NECB clause 8.4.3.6 does not apply for LEED projects.
    • Model baseline systems in accordance with NECB requirements, with DX coils replaced with chilled water coils if purchased cooling is present and fossil-fired furnaces replaced with hot water coils if purchased heating is present.
    • Option 1, Path 2: Do not apply ASHRAE 90.1-2010 requirements for baseline systems. Model baseline systems in accordance with NECB requirements for onsite generated equipment (i.e. assume building is not connected to a DES and the proposed building is modeled with a virtual plant according to LEED v4 Reference Guide requirements).

240 Comments

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R2M Solution Srl R2M Solution Srl
Jul 20 2017
LEEDuser Member
252 Thumbs Up

occupancy sensor in big offices

I read in paragraph 9.4.1.2 b. that "an occupant sensor or a timer switch shall be installed (...) in: (...) 6. office spaces up to 76.2m2".
Does it mean that for bigger offices (i.e. 100m2) no occupant sensor is needed? It sounds strange.

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Marcus Sheffer LEED Fellow, 7group Jul 20 2017 LEEDuser Expert 70262 Thumbs Up

No. Keep reading. Larger office space would come under 9.4.1.2c.

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R2M Solution Srl R2M Solution Srl Jul 20 2017 LEEDuser Member 252 Thumbs Up

"For spaces not included in 9.4.1.2b, each control device shall be activated either manually by an occupant or automatically by sensing an occupant".
It seems that an automatic control that turns lighting off when the occupants are not present is not requested, is it?

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Marcus Sheffer LEED Fellow, 7group Jul 20 2017 LEEDuser Expert 70262 Thumbs Up

Yep no occupant sensor is required as manual control are allowed. In larger, open office areas this makes sense most of the time because those spaces are rarely unoccupied. Occupancy sensors can also be used for compliance.

Whether they are needed or not also depends on the compliance path chosen for 9.4.1.1. Also note that plug in lighting may be affected by 8.4.2.

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R2M Solution Srl R2M Solution Srl Jul 20 2017 LEEDuser Member 252 Thumbs Up

Thanks.
TABLE G3.2 can be applied for big offices where occupancy sensors are installed, correct?

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Marcus Sheffer LEED Fellow, 7group Jul 20 2017 LEEDuser Expert 70262 Thumbs Up

Yes that gives you the LPDLighting power density (LPD) is the amount of electric lighting, usually measured in watts per square foot, being used to illuminate a given space. credit you can claim to demonstrate the energy savings associated with occupancy sensors.

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James Duggan Mr Noel Lawler Consultnig Engineers
Jul 20 2017
Guest

Ireland Climate Zone

Project Location: Ireland

Hi all,
Could anyone clarify if Ireland is in 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. 5A or 5C?

Thanks in advance

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Marcus Sheffer LEED Fellow, 7group Jul 20 2017 LEEDuser Expert 70262 Thumbs Up

According to ASHRAE Standard 169 the Ireland locations listed are either 4A or 5A.

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Quentin Jackson Sustainable Design Leader Aurecon
Jul 18 2017
LEEDuser Member
59 Thumbs Up

Compliance with ASHRAE 90.1 - 2010 - Air Tightness Query

Project Location: Australia

Hi there,

I'm working on stadium in Australia. For compliance with ASHRAE 90.1-2010, the window systems (frame + glazing) have to comply with the mandatory provisions (5.4) in ASHRAE 90.1-2010.

Specifically, 5.4.3.2 Fenestration and Doors, 'shall be determined in accordance with AAMA/WDMA/CSA 101/I.S.2/A440, NFRCNational Fenestration Rating Council (NFRC) is a non-profit organization that provides uniform, independent rating and labeling used to measure and compare energy performance of windows, doors, skylights, and attachment products. 400, or ASTMVoluntary standards development organization which creates source technical standards for materials, products, systems, and services E283'.

The architect has selected window systems which the air permeability has been tested according to EN 1026/12207 class 2 (we have received the certificate showing this).

Is the EN standard acceptable for compliance? As the stadium is in Australia, it has to pass our local codes and we only need compliance with ASHRAE 90.1-2010 to get the LEED rating. If the EN standard is not acceptable, how should we proceed?

Thanks!

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Marcus Sheffer LEED Fellow, 7group Jul 19 2017 LEEDuser Expert 70262 Thumbs Up

It sounds like that is the locally acceptable equivalent standard so it should be fine for LEED.

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Jess Scanlon Building Performance Engineer PAE Engineers
Jul 06 2017
Guest
2 Thumbs Up

District Energy for Partial Building Load

Project Location: United States

I am modeling a new building on a university campus following LEEDv4 Option 1, Whole Building Energy Simulation.
Heat Recovery Chillers are providing 44% of the cooling load of the building and the rest of the load is provided by campus chilled water.
Heat recovery from the chillers is the primary heating source for the building with campus steam providing what cannot be met by heat recovery.

Which path from the LEEDv4 Reference Guide for District Energy Systems should be followed for HVAC systems that use campus systems for partial loads?

How is the ASHRAE 2010 Appendix G baseline modeled when the proposed model uses partial energy from a district energy system? Does the baseline model need to be modeled with 44% on-site equipment with DESDistrict energy system: a central energy conversion plant and transmission and distribution system that provides thermal energy to a group of buildings (e.g., a central cooling plant on a university campus). It does not include central energy systems that provide only electricity. back up energy as well same as the proposed model?

Thanks!

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Marcus Sheffer LEED Fellow, 7group Jul 07 2017 LEEDuser Expert 70262 Thumbs Up

You would only model the campus sources according the the DESDistrict energy system: a central energy conversion plant and transmission and distribution system that provides thermal energy to a group of buildings (e.g., a central cooling plant on a university campus). It does not include central energy systems that provide only electricity.. You can use either DES option to model them.

The baseline is according to G3.1.1 and the DES guidance. Since the primary heat source is heat recovery that sounds like other to me so use that column from G3.1.1A. If you use DES Option 1 then the campus systems are purchased energy, if Option 2 then model the baseline as described there. If there is some sort of conflict in the baseline system choice then ask again with more specifics.

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Jess Scanlon Building Performance Engineer, PAE Engineers Jul 10 2017 Guest 2 Thumbs Up

If the campus system is only picking up peak loads and is not the primary fuel source, do I still model the baseline and proposed as if the campus system was the primary and only fuel source?

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Marcus Sheffer LEED Fellow, 7group Jul 10 2017 LEEDuser Expert 70262 Thumbs Up

No but it is a fuel source which is likely from fossil fuels. The question is whether your system is electric/other or fossil fuel/hybrid. After thinking this through some more I think it is hybrid assuming the fuel source for the district steam is a fossil fuel.

I considered splitting the systems and having separate baseline systems but there is no justification for that in Appendix G or the DESDistrict energy system: a central energy conversion plant and transmission and distribution system that provides thermal energy to a group of buildings (e.g., a central cooling plant on a university campus). It does not include central energy systems that provide only electricity..

I also considered whether it would be electric/other but since there are fossil fuels contributing to the heating it becomes hybrid. I also think it is not fair to be comparing the system you describe to electric resistance heat in terms of a reasonable accounting for the savings.

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Shenhao Li Atkins
Jul 05 2017
Guest
525 Thumbs Up

Energy Model for Ice Rink

Project Location: China

Hello,

We have a speed skating oval project. Should the energy used for ice rink modeled as process load? We think this will be the major energy consumption. Can we consider the energy saving of this load? If it can be, how to model the baseline chiller?

Thanks!

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Marcus Sheffer LEED Fellow, 7group Jul 05 2017 LEEDuser Expert 70262 Thumbs Up

Yes it is a process load.

You can claim savings through an exceptional calculation. Under this method you must justify the baseline as standard industry practice for an new facility in your area.

If the chiller used is the same type as can be used for space conditioning you can use the efficiency in Table 6.8.1 for the baseline.

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Shenhao Li Atkins Jul 05 2017 Guest 525 Thumbs Up

Thank you Marcus!

The window wall ratio also need to adjust to 40% maximum?

And the energy used for ice rink will be affected by building envelope which are not same for baseline and proposed case. So this process load won't be the same for two models.

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Marcus Sheffer LEED Fellow, 7group Jul 06 2017 LEEDuser Expert 70262 Thumbs Up

Yes.

The process load must be the same but that does not mean that the energy use must be the same. In most cases it is the same but in some situations other interactive strategies produce savings and that is OK. So you model it identically and make sure to thoroughly explain any savings to the reviewer.

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Shenhao Li Atkins Jul 07 2017 Guest 525 Thumbs Up

Thank you!

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Todd Tewksbury Mechanical Engineer Bala Consulting Engineers, Inc
Jun 22 2017
Guest
18 Thumbs Up

Virtual DES Energy Rates

Project Location: United States

When modeling district cooling and heating systems using Option 1, Path 1: ASHRAE 90.1-2010 Appendix G, the LEED Reference Guide instructs the following:
"If tariffs or rates are not available from the district plant serving the project, such as for campus or military plants, calculate the rates based on the virtual electric and fossil fuel rates from the model."

The Reference Guide does not elaborate as to how this is done.

Without actual utility rates, we reference EIA for our virtual electric and natural gas rates, which we plug in to the model economics to show energy cost.
Back in LEED 2009, the District Energy Systems Guidance document provided formulas to calculate the virtual rate of district chilled water, steam, and hot water based on the virtual electricity and/or gas rates.

Are these formulas still applicable for LEED v4 projects?

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Marcus Sheffer LEED Fellow, 7group Jun 23 2017 LEEDuser Expert 70262 Thumbs Up

Those formulas and complete instructions on how to calculate the rate is in the online version of the Reference Guide. Do you have a paper copy? If it is not there then maybe in an addenda?

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Todd Tewksbury Mechanical Engineer, Bala Consulting Engineers, Inc Jun 26 2017 Guest 18 Thumbs Up

Thank you for the tip, Marcus. The formulas were added to the addendum document about two months ago.

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Hanh Truong Green Building Consultant Artelia
Jun 15 2017
Guest
13 Thumbs Up

Energy modeling for LEED BD+C: Core & Shell

Project Location: Vietnam

Dear all,

We have a project targeting LEED BD+C: Core & Shell. My question is how to model whole-building energy simulation? Do we need to take into account the energy consumption of tenant spaces? We currently don't have information for lighting at tenant areas.
Thank you for your time and support

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Billy Condor Engineer Jun 19 2017 Guest 46 Thumbs Up

You must follow appendix G (table 3.1) of ASHRAE 90.1-2010, it mentions how to model the whole building including core and tenants spaces, for HVAC equipment, lighting system, etc.
For instance, if you currently don't have information for lighting at tenant areas (as usual at C&S projects), table G3.1-6c says: "Where lighting neither exists nor is specified, lighting power shall be determined in accordance with the Building Area Method for the appropriate building type.", therefore for tenant areas, set Lighting Power Densities according to Table 9.5.1 for Baseline and Proposed models.

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R2M Solution Srl R2M Solution Srl
Jun 07 2017
LEEDuser Member
252 Thumbs Up

mandatory for air leakage in Europe

Project Location: Italy

How can you demonstrate the compliance with the mandatory provisions relative to air leakage of the envelope (both walls and fenestrations) of ASHRAE 90.1-2010 (par. 5.4.3.1.2, 5.4.3.1.3, 5.4.3.2) in Europe? Do you use European standards (e.g. EN 1026 and EN 12207)?

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Marcus Sheffer LEED Fellow, 7group Jun 09 2017 LEEDuser Expert 70262 Thumbs Up

There is no specific documentation required for LEED to demonstrate compliance with the mandatory provisions. Design professionals are assumed to be ensuring compliance with them. These particular provisions are not quantitative so demonstrating compliance would be simply a statement from the professionals involved that the project complies. I am not familiar with the European Standards on the subject.

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Jean Marais b.i.g. Bechtold DesignBuilder Expert Jun 09 2017 LEEDuser Member 11109 Thumbs Up

This section does not require test results, so I would accept if your construction documents (tender documents) list that these works must be done to a standard that describes the proceedures (like taping, etc.) that are also required by 5.4.3.1.2 & 3.

The materials and assemblies listed in 5.4.3.1.3 are already acceptable and really do cover most of those that one uses. Non-listed materials and assemblies usually have published values for air permeance albeit to other testing proceedures. I would be able to do a rough conversion from, for example a different pressure differential of 50 Pa, to what the flowrate would be at 75 Pa (as required by ASHRAE). If I think that the rate is safely better than the requirement, I will use my "engineering judgement" to say that it meets the requirement. As no proof is required, I would challange any challenger to proove me wrong.

As mentioned before, you are not required to show a datasheet where the material or assembly lists it's results from being tested to the american standard...only that you undersign that it would comply if tested.

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Edgar Arevalo
Jun 06 2017
Guest
68 Thumbs Up

Parametric Rotation Runs for Baseline model of Existing Building

Project Location: United States

Since the energy model is based off of an existing building. Do I still need to perform parametric rotational runs (0 deg, 90 deg, 180 deg, and 270 deg) for a baseline model based on the existing structure?

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Marcus Sheffer LEED Fellow, 7group Jun 06 2017 LEEDuser Expert 70262 Thumbs Up

Existing structures are not required to be rotated.

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Edgar Arevalo Jun 06 2017 Guest 68 Thumbs Up

Thank you.

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Jean-Baptiste SARFATI Environmental adviser - LEED AP ID+C OASIIS
May 31 2017
Guest
64 Thumbs Up

Climate Zone for Morocco

Project Location: Morocco

Hi,

I'm working on a pre-assessment for a project in Morocco and would like to see the minimum wall insulation.
I checked in ASHRAE 90.1-2010 but Morocco is not listed in Table B3 International Climate Zones.

Does anyone already had this issue and now what climate zone is appropriate for Morocco ?

Thank you for your help.

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R2M Solution Srl R2M Solution Srl May 31 2017 LEEDuser Member 252 Thumbs Up

Look for the .stat file in the EnergyPlus weather database. The .epw files can be used also in other software (e.g. in IES-VE).
Best Regards

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Jean-Baptiste SARFATI Environmental adviser - LEED AP ID+C, OASIIS May 31 2017 Guest 64 Thumbs Up

Thank you for your answer. The datas will be useful to make the calculation in the future.
But for the moment I'm looking 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. of Morocco (1B, 2A, 3A, 3B ?). I need it to check the insulation thickness needed on the project.

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Jean Marais b.i.g. Bechtold DesignBuilder Expert May 31 2017 LEEDuser Member 11109 Thumbs Up

A word of warning. The climate zones generated in the .stat files are based on the statistical yearly weather file AND DO NOT always correspond to those listed in Standard 90.1. THEY MAY NOT ALWAYS BE THE SAME and you have to use those in Standard 90.1, if listed.

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Jean-Baptiste SARFATI Environmental adviser - LEED AP ID+C, OASIIS May 31 2017 Guest 64 Thumbs Up

Thank you for your answer.
If it is not listed do you know where I could find it ?

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Jean Marais b.i.g. Bechtold DesignBuilder Expert May 31 2017 LEEDuser Member 11109 Thumbs Up

Well then you need to calculate it. HOF lists the Heat./Cool. Degree-Days (HDD / CDDA measure of how hot a location was over a period of time, relative to a base temperature. In this report, the base temperature is 65 degrees Fahrenheit, and the period of time is one year. The cooling degree-day is the difference between that day's average temperature and 65 degrees if the daily average is greater than 65; it is zero if the daily average temperature is less than or equal to 65. Cooling degree-days for a year are the sum of the daily cooling degree-days for that year. 18.3) for Morroco for 11 different locations. Google CZTables.pdf to see the calculation proceedure at the end.

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Jean-Baptiste SARFATI Environmental adviser - LEED AP ID+C, OASIIS May 31 2017 Guest 64 Thumbs Up

I received an answer from ASHRAE :

Table B-4 includes a chart to let you determine 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. based on HDD and CDDA measure of how hot a location was over a period of time, relative to a base temperature. In this report, the base temperature is 65 degrees Fahrenheit, and the period of time is one year. The cooling degree-day is the difference between that day's average temperature and 65 degrees if the daily average is greater than 65; it is zero if the daily average temperature is less than or equal to 65. Cooling degree-days for a year are the sum of the daily cooling degree-days for that year. of the location. The degree day information can be found in ASHRAE Standard 169 or the ASHRAE Handbook. From the ASHRAE Standard 169-2013, most Moroccan cities appear to be climate zone 3 or 2:

Morocco (MAR) Zoning
AGADIR 3B
AGADIR AL MASSIRA 2B
AL HOCEIMA 3B
BENI-MELLAL 3A
CASABLANCA 3A
ERRACHIDIA 2B
ESSAOUIRA 3C
FES-SAIS 3A
MARRAKECH 2B
MEKNES 3A
MIDELT 3B
NADOR-AROUI 3B
NOUASSEUR 3A
OUARZAZATE 2B
OUJDA 3B
RABAT-SALE 3A
SAFI 3A
TANGER (AERODROME) 3A
TAZA 3A
TETUAN/SANIA RAMEL 3A

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Muzammal Abbas LEED AP (BD+C) MEP Engineer Pakistan Green Building Council
May 24 2017
Guest
90 Thumbs Up

Proposed Case-Process Load

Project Location: Pakistan

Hi,

Is there any limitations in LEED V4 regarding process energy that it should be minimum 25% (In proposed case) of the baseline energy cost for the building.

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Marcus Sheffer LEED Fellow, 7group May 24 2017 LEEDuser Expert 70262 Thumbs Up

No this specific percentage has been removed. Projects will however be evaluated based on whether the process loads included in the model are accurately addressing all energy use within the the building.

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Alexandra Mazzoni AIA
May 23 2017
Guest
2 Thumbs Up

Minimum Energy Performance

Project Location: France

Hello,
I have a question regarding equivalent standards : Is there an USGBC approved equivalent standard for projects located in France ?

Many thanks in advance for your assistance.

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Marcus Sheffer LEED Fellow, 7group May 24 2017 LEEDuser Expert 70262 Thumbs Up

I am not aware of equivalency being granted for any French or EU standards.

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Aaron Luthien
May 10 2017
Guest
401 Thumbs Up

Waste Heat from Landfill Gas Plant

Project Location: Germany

Hello all,

We have an office project which utilizes waste heat from the neighbor landfill gas plant. The plant and office is owned by the same company. The plant produces electricity from landfill gas from nearby landfill (200 meters away) and delivers it to the grid. The office will use the waste heat generated during the electricity production for heating and cooling purposes. All cooling and heating energy will be provided by waste heat. The waste heat from the plant is not going to serve any other buildings and there is more than enough heat for the building.

We believe that this strategy should contribute to the energy efficiency and renewable energy credits since landfill gas is accepted as renewable energy resource and waste heat is utilized. However, we are not sure how to document it. Do you have any experience about it?

I appreciate any advise.

Thank you!

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Marcus Sheffer LEED Fellow, 7group May 24 2017 LEEDuser Expert 70262 Thumbs Up

There are probably some variables which would enable you model this a few different ways.Here is what I would probably do.

I would model the baseline according to Table G3.1.1A using the column for purchased heat. I would model the proposed as designed. I would use the same fuel rates for both models. Then zero out the energy cost for heating and cooling in the proposed by counting all the waste heat as a renewable energy source.

You should provide some sort of narrative justification for the baseline and use some local fuel rates. You could probably justify natural gas or purchased energy for heating. Also provide a narrative justification for treating the fuel source as renewable.

I think this is the simplest way to do it. There may be some other variations that would work but essentially you want renewable credit for the fuel source.

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Aaron Luthien May 26 2017 Guest 401 Thumbs Up

Marcus, thanks a lot! I will try to do as you described.

Thanks!

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R2M Solution Srl R2M Solution Srl
May 09 2017
LEEDuser Member
252 Thumbs Up

Existing Equipment

Project Location: Italy

The 90.1-2010 User's Manual states:
"In some cases, a complete HVAC system already exists (...) the proposed building and baseline building models are the same and are based on the existing HVAC system".
Is that statement valid also for the ventilation air flow rates (i.e., is exception c. of G3.1.2.6 not valid?)?

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Marcus Sheffer LEED Fellow, 7group May 10 2017 LEEDuser Expert 70262 Thumbs Up

That is correct if the existing system remains unchanged. The existing system is modeled identically. It must, however, also comply with ASHRAE 62,1. So if is does not comply it must be modified to do so. If it is modified then G3..1.2.6 (c) is valid.

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Nicole Isle Chief Sustainability Strategist Glumac
Apr 27 2017
LEEDuser Member
38 Thumbs Up

Baseline window Visible Light Transmittance (VLT)

Hi Marcus,
Do you know if USGBC has taken a position on what the baseline window VLT should be? Now that daylighting is included in the baseline, this plays a much bigger role than it did in v3. I don't see anything about this in 90.1-2010.
Thanks as always!

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Marcus Sheffer LEED Fellow, 7group Apr 27 2017 LEEDuser Expert 70262 Thumbs Up

ASHRAE 90.1-2013 addresses this issue as a ratio of 1.1 VLT/SHGCSolar heat gain coefficient (SHGC): The fraction of solar gain admitted through a window, expressed as a number between 0 and 1.. I assume that would be used. I'll see what I can find out.

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Marcus Sheffer LEED Fellow, 7group Apr 27 2017 LEEDuser Expert 70262 Thumbs Up

I am not aware of any particular ruling on this issue. Typically if the standard is silent you would model it the same as the Proposed VLT.

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Jean Marais b.i.g. Bechtold DesignBuilder Expert Apr 28 2017 LEEDuser Member 11109 Thumbs Up

Some modeling programs are set up to model real life physics. Just like energyplus has a hard time to model a large window with rediculous SHGCSolar heat gain coefficient (SHGC): The fraction of solar gain admitted through a window, expressed as a number between 0 and 1. (unless you have almost more frame than glass), some combinations of VLT, SHGC and U-Values are just not going to occur due to that irritable real life factor that we try our best to describe with modern physics. Bottom line is that, although Markus is right, it might not always be possible to use the same VLT with a different window. That ratio approach sounds good to me. We just need LEED to accept it for 90.1-2010.

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Cory Duggin Energy Project Engineer, TLC Engineering for Architecture Apr 28 2017 LEEDuser Member 176 Thumbs Up

The ratio of 1.1 VLT/SHGCSolar heat gain coefficient (SHGC): The fraction of solar gain admitted through a window, expressed as a number between 0 and 1. is what I have successfully used on LEED projects, and to my knowledge it is the only reference 90.1 makes to VLT.

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Sarah Sachs Buro Happold
Apr 26 2017
LEEDuser Member
322 Thumbs Up

Account for local and utility central energy plants

Project Location: United States

We are building an addition to an existing building that has a central plant that is outside of our LEED boundary. However, we also have a contract to improve the performance of the central plant. We are purchasing steam from Con Edison. Under LEED, we are allowed to either Option 1 Path 1, where by we assign costs to all purchased energy, or Option 1 Path 2, whereby we account for the central plant. Is it possible to use Path 2 to account for the central cooling plant, which is owned by the project owners, without accounting for the central heating plant, which is owned by ConEdison? In this scenario, we would still use the purchased rate of steam to price our heating energy.

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Marcus Sheffer LEED Fellow, 7group Apr 26 2017 LEEDuser Expert 70262 Thumbs Up

I think you could apply different options to the different plants. So you could do Option 1 for heat and Option 2 for cooling.

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Sefa Sahin
Apr 26 2017
Guest
8 Thumbs Up

Sea Water Cooled Chiller Modeling

Project Location: Turkey

Dear All,

Our project building is located in Istanbul/Turkey. Cooling will be provided by centralised two chillers. There is not a cooling tower. The project building location is very close the sea and this chillers will be fed by the sea-water condenser system.
There is a titanium plate type heat exchanger between sea-water and chiller condenser water. Sea water condenser flow and return temperatures 22C(71.6F) and 27C(80.6F).
Chiller condenser water flow and return temperatures 29C(84.2F) and 23C(73.4F). In addition, condenser total water flow rate is 340 kg/hr at 250 kPa.
How can sea-water condenser system be modeled in eQuest?

Thank you,
Best Regards.

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Marcus Sheffer LEED Fellow, 7group Apr 26 2017 LEEDuser Expert 70262 Thumbs Up

I think this would be possible with some type of water cooled condenser. Without going into the program and trying to figure it out I can't give you a step-by-step set of instructions. For LEED if it can't be modeled directly a work around would be required. If it is required make sure to follow G2.5 and provide a thorough narrative describing the work around.

You might also consider posting your question on the eQUEST users forum at onebuilding.org. Someone there would be more likely to have an answer to your question.

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R2M Solution Srl R2M Solution Srl
Apr 15 2017
LEEDuser Member
252 Thumbs Up

Demolished and rebuilt envelope

Project Location: Italy

If the envelope is demolished and then rebuilt with the same shape does Table G3.1 part 5., baseline, point f apply? It states: "For existing building envelopes, the baseline building design shall reflect existing conditions prior to any revisions that are part of the scope of work being evaluated."
Best Regards

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Marcus Sheffer LEED Fellow, 7group Apr 17 2017 LEEDuser Expert 70262 Thumbs Up

No, it becomes new construction. It is no longer existing when it this torn down.

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Quentin Jackson Sustainable Design Leader Aurecon
Apr 13 2017
LEEDuser Member
59 Thumbs Up

Energy Modelling - Australia

Project Location: Australia

We have a Green Building Council in Australia that has a very advanced energy simulation methodology that achieves the same outcomes as the ASHRAE 90.1 process outlined in LEED. It is also well aligned to local requirements for demonstrating compliance with local codes. Our project (a stadium) now needs to create numerous energy models to essentially demonstrate the same thing by different methodologies creating an inordinate amount of extra work for no useful output.

It wouldn't be hard to use the Green Building Council of Australia's energy modelling methodology and adjust the points scale to match LEED and thus allow Australian projects to follow the GBCA Method instead of ASHRAE 90.1.

Has anyone successfully done this in other countries - to use a more appropriate local methodology instead of ASHRAE 90.1 get the LEED energy points? If so keen to understand how we can develop a conversion process to convince the USGBC to agree! (would save a huge amount of modelling work whilst ensuring the outcomes are still met).

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Marcus Sheffer LEED Fellow, 7group Apr 13 2017 LEEDuser Expert 70262 Thumbs Up

It has been done in a few places. The process is spelled out in this document - http://www.usgbc.org/resources/leed-reference-guide-green-building-desig... - I have not seen one specific to v4 but I think the process would be the same.

It is a pretty involved process which is usually undertaken by a governmental entity or nonprofit with funding to do so. Here is the process:

The following process is used to determine the equivalency of a local standard to ANSI/ASHRAE/IESNA Standard 90.1–2010.
1. A group interested in determining equivalency of a particular standard should email a request to USGBC through commonlanguage@usgbc.org.
2. USGBC will collaborate with the group to establish a method for creating an equivalency study and a timeline for completion.
3. The group will conduct the study.
4. USGBC will review the study and bring its recommendation to the LEED International Roundtable with approval by the LEED Steering Committee.
5. Typically, the group putting forward the standard will cover the cost of the study and USGBC review.
6. Priority of USGBC review will be determined based on market transformation potential and representation of the country on the LEED International Roundtable.
7. Approval of equivalency will be determined by the LEED Steering Committee and communicated to the group.
8. Upon approval by the LEED Steering Committee, the equivalency will be made available to projects through a USGBC-administered 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..

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Martin Meehan Principal Meehan Associates
Apr 11 2017
LEEDuser Member
455 Thumbs Up

Air Barrier for Existing Building

Hi all,

This query follows on a similar theme to the previous topic.

We are working on an existing building that is intending to improve the envelop performance by internally adding insulation to all external walls.
There will be no other alterations to the envelope.

1) Given that we are altering and thermally improving the existing external wall - do we have to also install an air barrier per 5.4.3.1.2?
2) Are the other envelope elements that remain unchanged such as the floor/roof exempt from air barrier requirements?

Thanks!

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Marcus Sheffer LEED Fellow, 7group Apr 11 2017 LEEDuser Expert 70262 Thumbs Up

I think you do what is accessible during construction. So implement everything you can. You would not be required to significantly alter the wall assembly to install any component that you cannot physically install without a major disassembly of the walls.

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Alex Parella Architect_LEED AP
Mar 30 2017
LEEDuser Member
169 Thumbs Up

ASHRAE installations mandatory provisions in Major Renovations

Dear all,

We intend to certify and existing office building, which is going to be retrofitted with the following criteria:

-No intervention in the envelope
-Partial replacement of the HVAC (both production and distribution systems) and lighting/electrical.

In principle, the envelope ASHRAE mandatory requirements should only be met by the modified elements.

Does the same principle apply for the HVAC and lighting installations?
Or should they be totally renewed in order to fulfill the ASHRAE mandatory requirements?

thanks in advance

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Marcus Sheffer LEED Fellow, 7group Mar 31 2017 LEEDuser Expert 70262 Thumbs Up

I agree that you only need to meet the mandatory provisions relative to the items you change. Any unchanged system components are modeled identically.

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Alex Parella Architect_LEED AP Apr 01 2017 LEEDuser Member 169 Thumbs Up

Thanks Marcus,

Another question arises from your answer:

The modeling procedure for the Envelope of Existing buildings in the Baseline is totally explicit in Apendix G:

"f. Existing Buildings. For existing building envelopes, the baseline building
design shall reflect existing conditions prior to any revisions that are part of
the scope of work being evaluated."

Do the systems follow the same logic? That means, modeling the "baseline" systems according the current state.
Or should they be settled following "TABLE G3.1.1A Baseline HVAC System Types"?

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Marcus Sheffer LEED Fellow, 7group Apr 01 2017 LEEDuser Expert 70262 Thumbs Up

No. Unchanged lighting and HVAC is modeled identically. If you change it then the baseline is Appendix G.

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Alex Parella Architect_LEED AP Apr 03 2017 LEEDuser Member 169 Thumbs Up

Thanks Marcus

Last question:

The current HVAC system is going to maintain its typology, but almost all the units will be replaced by more efficient ones (VRV and generation). The pipelines won't be replaced.

We interpretate that:

-All these replaced units have to fulfill the ASHRAE requirements.

-We can simulate our current HVAC system typology in both, the "baseline" and the "proposed", only changing the efficency and specific parameters (required by ASHRAE) of the replaced units.
(instead of using the generic reference system for the "baseline" defined in the Appendix G)

Is that right?

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K Nakamura
Mar 14 2017
Guest
105 Thumbs Up

Elementary School

Project Location: United States

Is there any special considerations for a project registered (v2.2) and designed 10 years ago is now being constructed. V2.2 and v2009 have expired so we need to register it for v4. However, since it was designed to ASHRAE 90.1-2004, it does not comply with ASHREE 90.1-2010.

Thank you.

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Marcus Sheffer LEED Fellow, 7group Mar 15 2017 LEEDuser Expert 70262 Thumbs Up

Does it comply with 90.1-2007?

Probably your only option would be to upgrade your registration to LEED 2009. If the project was registered already you should be able to transfer the registration. I would think USGBC would let you. It can't hurt to ask.

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Mark Benson
Mar 10 2017
Guest
400 Thumbs Up

Using different energy rates between CHP Proposed and Baseline

Project Location: United States

I know that the 90.1 and the LEED Reference Guide generally tell you to use the same utility rate structures for both the Proposed and Baseline models. But what happens when the Proposed model uses Full Accounting of DESDistrict energy system: a central energy conversion plant and transmission and distribution system that provides thermal energy to a group of buildings (e.g., a central cooling plant on a university campus). It does not include central energy systems that provide only electricity. and includes DES-CHPCombined heat and power (CHP), or cogeneration, generates both electrical power and thermal energy from a single fuel source.-supplied electricity and steam, while the Baseline uses On-site Boilers and grid-tied electricity? The DES is charged $0.45/therm while a new gas service at the Baseline Project Building would be charged $0.73/therm due to inherently different rate structures).

I've provided a link below to a CHP LEED Calculator (provided by the EPA CHP Partnership) which instructs the user to use $0.45/therm in the Proposed model since it is a special price for CHP gas and $0.73/therm in my Baseline model (See Inputs tab, rows 14 and 17). Is this acceptable from a USGBC perspective? Thanks!

http://epa.gov/chp/documents/chp_leed_calculator.xlsm

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Marcus Sheffer LEED Fellow, 7group Mar 13 2017 LEEDuser Expert 70262 Thumbs Up

The rates must be identical for LEED. The Baseline system in this case is a virtual DESDistrict energy system: a central energy conversion plant and transmission and distribution system that provides thermal energy to a group of buildings (e.g., a central cooling plant on a university campus). It does not include central energy systems that provide only electricity. so it must use the same rate as the Proposed case.

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Jul 24 2017
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