Add "or USGBC approved equivalent" to the end of the first sentence of the third bullet.
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Credit language
© Copyright U.S. Green Building Council, Inc. All rights reserved.
Requirements
3 points mandatory for projects registered on or after April 8, 2016.
Whole building energy simulation (1-24 points)
Demonstrate a percentage improvement in the proposed building performance rating compared with the baseline building performance rating. Calculate the baseline building performance according to Appendix G of ANSI/ASHRAE/IESNA Standard 90.1-2007 (with errata but without addenda1) using a computer simulation model for the whole building project. Projects outside the U.S. may use a USGBC approved equivalent standard2. The minimum energy cost savings percentage for each point threshold is as follows:New Buildings |
Existing Building Renovations |
Points |
|---|---|---|
12% |
8% |
1 |
14% |
10% |
2 |
16% |
12% |
3 |
18% |
14% |
5 |
20% |
16% |
7 |
22% |
18% |
9 |
24% |
20% |
11 |
26% |
22% |
13 |
28% |
24% |
14 |
30% |
26% |
15 |
32% |
28% |
16 |
34% |
30% |
17 |
36% |
32% |
18 |
38% |
34% |
19 |
40% |
36% |
20 |
42% |
38% |
21 |
44% |
40% |
22 |
46% |
42% |
23 |
48% |
44% |
24 |
- Compliance with the mandatory provisions (Sections 5.4, 6.4, 7.4, 8.4, 9.4 and 10.4) in Standard 90.1-2007 (with errata but without addenda1) or USGBC approved equivalent.
- Inclusion of all the energy costs within and associated with the building project.
- Comparison against a baseline building that complies with Appendix G of Standard 90.1-2007 (with errata but without addenda1) or USGBC approved equivalent. The default process energy cost is 25% of the total energy cost for the baseline building. If the building’s process energy cost is less than 25% of the baseline building energy cost, the LEED submittal must include documentation substantiating that process energy inputs are appropriate.
1Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.
2 Projects outside the U.S. may use an alternative standard to ANSI/ASHRAE/IESNA Standard 90.1-2007 if it is approved by USGBC as an equivalent standard using the process identified in the LEED 2009 Green Building Design and Construction Global ACP Reference Guide Supplement.
Pilot ACPs Available
The following pilot alternative compliance path is available for this credit. See the pilot credit library for more information. EApc95: Alternative Energy Performance Metric ACPWhat does it cost?
Cost estimates for this credit
On each BD+C v4 credit, LEEDuser offers the wisdom of a team of architects, engineers, cost estimators, and LEED experts with hundreds of LEED projects between then. They analyzed the sustainable design strategies associated with each LEED credit, but also to assign actual costs to those strategies.
Our tab contains overall cost guidance, notes on what “soft costs” to expect, and a strategy-by-strategy breakdown of what to consider and what it might cost, in percentage premiums, actual costs, or both.
This information is also available in a full PDF download in The Cost of LEED v4 report.
Learn more about The Cost of LEED v4 »Frequently asked questions
See all forum discussions about this credit »Addenda
1/15/2016 – Updated: 4/7/2016
Form Update
Campus Applicable
No
Internationally Applicable:
No
10/1/2012 – Updated: 2/14/2015
Global ACP
Description of change:
Campus Applicable
No
Internationally Applicable:
Yes
10/1/2012 – Updated: 2/14/2015
Global ACP
Description of change:
Add "Projects outside the U.S. may use a USGBC approved equivalent standard." Before the last sentence of the first paragraph.
Campus Applicable
No
Internationally Applicable:
Yes
11/1/2011 – Updated: 2/14/2015
Reference Guide Correction
Description of change:
In the text "ASHRAE Advanced Energy Design Guide for Small Office Buildings, 2006," replace 2006 with 2004
Campus Applicable
No
Internationally Applicable:
No
10/1/2012 – Updated: 2/14/2015
Global ACP
Description of change:
Add the following footnote to the bottom of the page: "Projects outside the U.S. may use an alternative standard to ANSI/ASHRAE/IESNA Standard 90.1-2007 if it is approved by USGBC as an equivalent standard using the process located at www.usgbc.org/leedisglobal"
Campus Applicable
No
Internationally Applicable:
Yes
10/1/2012 – Updated: 2/14/2015
Global ACP
Description of change:
Add "or USGBC approved equivalent" to the end of the first bullet.
Campus Applicable
No
Internationally Applicable:
Yes
10/1/2012 – Updated: 2/14/2015
Global ACP
Description of change:
Add "or USGBC approved equivalent" after the parenthetical in the third paragraph after the bulleted list.
Campus Applicable
No
Internationally Applicable:
Yes
7/2/2018
LEED Interpretation
Inquiry:
Our project is located in California. To pursue Option 1: Whole Building Simulation, is there a methodology for documenting additional energy performance for LEED v4 projects regulated by Title 24-2016?
Ruling:
Project Type1
Additional Percent Savings
NC-Office
7%
NC-Retail (except restaurant/grocery)
8%
NC-School
7%
NC-Health Care
0%
NC-Restaurant/Grocery
0%
NC-Hospitality
8%
NC-Warehouse
0%
NC-Multifamily
8%
NC-All Other
0%
CS-Office
5%
CS-Retail (except restaurant/grocery)
7%
CS-School
5%
CS-Health Care
0%
CS-Restaurant/Grocery
0%
CS-Hospitality
7%
CS-Warehouse
0%
CS-Multifamily
7%
CS-All Other
0%
CI-Office
6%
CI-Retail (except restaurant/grocery)
7%
CI-School
6%
CI-Health Care
0%
CI-Restaurant/Grocery
0%
CI-Hospitality
7%
CI-Warehouse
0%
CI-Multifamily
7%
CI-All Other
0%
Campus Applicable
No
Internationally Applicable:
No
10/1/2012
LEED Interpretation
Inquiry:
Many projects in Europe are connected to highly efficient district energy systems. However, the EAp2/EAc1 Option 2 guidance provided in the "Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction" (DESv2) document is not well-suited for the complex interconnected district energy systems with multiple fuel sources that are common in Europe. Many European countries already make use of the Primary Energy Factor (PEF) as a means of evaluating district energy performance and building energy performance. Is there an alternative compliance path available to document EAp2/EAc1 credit for the district energy system using the Primary Energy Factor in lieu of the DESv2 Option 2 compliance path?
Ruling:
An alternative EAp2/EAc1 compliance path is available to document the energy performance for complex interconnected district energy systems in Europe using the Primary Energy Factor and the greenhouse gas emissions associated with these systems. The Sweden Green Building Council developed an approved method, "Treatment of European District Energy Systems in LEED" (available November 1, 2012), which may be used in lieu of EAp2 Option 2 of the "Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction" guidance. This compliance path is currently available for projects located in Europe only. The guidance is located at Note: The "Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction" (DESv2) is Optional Guidance for LEED 2009 projects. However, project teams that use the guidance must apply all relevant portions of the guidance. The alternative compliance path outlined in the "Treatment of European District Energy Systems in LEED" may only be used to replace Option 2 of the EAp2/EAc1 Energy Modeling Path defined in the DES v2 guidance. Project teams that opt to use the "Treatment of European District Energy Systems in LEED" method must comply with all other applicable requirements of the DES v2 guidance such as those defined for EA Credit 3, EA Credit 4, EA Credit 5, etc. Applicable Internationally; only for projects located in the Europe region.
Campus Applicable
No
Internationally Applicable:
Yes
10/1/2013
LEED Interpretation
Inquiry:
A centrifugal chiller, manufactured in Brazil, is specified for the project. The chiller is not AHRI certified and there is no laboratory in Brazil that can do this test. Since there is no laboratory in Brazil that can do this test, to comply with section 6.4.1.4 Verification of Equipment Efficiencies of ASHRAE 90.1-2007 Standard, would the equipment fall under option d (if no certification program exists for a covered product, the equipment efficiency ratings shall be supported by data furnished by the manufacturer)? Can this equipment be used in the project?
Ruling:
A supplier’s claims regarding energy efficiency would not be considered sufficient to document compliance with EA Prerequisite 2 (Minimum Energy Performance) and EA Credit 1 (Optimize Energy Performance) for a centrifugal HVAC unit that has not been tested and certified by a 3rd party in accordance with AHRI Standard 550-590. However, if the project team can provide documentation that the efficiency has been tested by a third party using an equivalent standard for HVAC efficiency, this testing would be sufficient in lieu of the AHRI Standard 550-990 testing. Any differences in test conditions and the resulting adjustments to the efficiency values claimed in the energy model would need to be described in the project submittal documentation. Alternatively, the project team may use the supplier’s claims regarding energy efficiency if the commissioning scope of work includes field testing of the equipment efficiency for the range of full- and part-load design conditions under which the building will operate; any adjustments related to altitude, etc. must be accounted for in the commissioning testing. In this case, the energy modeling documentation must include details about the commissioning functional testing method to confirm the performance of the chiller at full and part load operation. If the LEED submittal is provided as a split design / construction phase submittal, and the commissioning agent determines that the equipment efficiency does not meet or exceed the efficiency values claimed by the supplier, the energy documentation must be resubmitted at the construction phase with the values measured by the commissioning agent.
Campus Applicable
No
Internationally Applicable:
Yes
7/1/2014
LEED Interpretation
Inquiry:
There is significant confusion, and seemingly contradictory LEED Interpretations on the required methodology for addressing “purchased” on-site renewable energy, and/or purchased biofuel that is not considered on-site renewable energy within the LEED energy model. For renewable fuels meeting the requirements of Addendum 100001081 (November 1, 2011) or other purchased renewable fuels, how should purchased on-site renewable energy be treated in the LEED energy model? How should purchased bio-fuels (meaning it I not fossil fuel but is used in a similar manner to bio-fuel) be treated in the energy model?
Ruling:
For any on-site renewable fuel source that is purchased (such as qualifying wood pellets, etc.), or for biofuels not qualifying as on-site renewable fuel sources that are purchased, the actual energy costs associated with the purchased energy must be modeled in EA Prerequisite 2: Minimum Energy Performance and EA Credit 1: Optimize Energy Performance, and the renewable fuel source may not be modeled as "free", since it is a purchased energy source.
For non-traditional fuel sources (such as wood pellets) that are unregulated within ASHRAE 90.1, use the actual cost of the fuel, and provide documentation to substantiate the cost for the non-traditional fuel source. The same rates are to be used for the baseline and proposed buildings, with the following exception: If the fuel source is available at a discounted cost because it would otherwise be sent to the landfill or similarly disposed of, the project team may use local rates for the fuel for the baseline case and actual rates for the proposed case, as long as documentation is provided substantiating the difference in rates, and substantiating that the fuel source would otherwise be disposed of.
When these non-traditional fuel sources are used for heating the building, the proposed case heating source must be the same as the baseline case for systems using the non-traditional fuel source, and the project team must use fossil fuel efficiencies for the Baseline systems, or provide evidence justifying that the baseline efficiencies represent standard practice for a similar, newly constructed project with the same fuel source.
Updated 8/7/17 for rating system applicability.
Campus Applicable
Yes
Internationally Applicable:
Yes
7/2/2018
LEED Interpretation
Inquiry:
Our project is subject to ASHRAE Standard 90.1-2013 for code compliance. To pursue Option 1: Whole Building Simulation, is there a methodology for documenting additional energy performance for LEED v4 projects regulated by ASHRAE Standard 90.1-2013?
Ruling:
Yes, projects applying Option 1: Whole Building Simulation, and regulated by ASHRAE Standard 90.1-2013 may document additional energy performance improvement under LEED v4 EA credit Optimize Energy Performance as described below. The Appendix G modeling method must be used for the LEED submission, even if the Energy Cost Budget method is used to document local code compliance.
Projects may calculate the Equivalent ASHRAE 90.1-2010 Performance improvement as:
Equivalent performance Improvement = % better than ASHRAE 90.1-2013 + Additional Percent Savings
Where Additional Percent Savings is shown in Table 1:
Table 1: Additional Percent Savings for ASHRAE 90.1-2013
Project Type1 Additional Percent Savings
NC-Office 5%
NC-Retail (except restaurant/grocery) 5%
NC-School 6%
NC-Health Care 3%
NC-Restaurant / Grocery 3%
NC-Hospitality 5%
NC-Warehouse 1%
NC-Multifamily 3%
NC-All Other 2%
CS-Office 3%
CS-Retail (except restaurant/grocery) 3%
CS-School 6%
CS-Health Care 1%
CS-Restaurant / Grocery 2%
CS-Hospitality 3%
CS-Warehouse 0%
CS-Multifamily 1%
CS-All Other 1%
CI-Office 3%
CI-Retail (except restaurant/grocery) 4%
CI-School 6%
CI-Health Care 2%
CI-Restaurant / Grocery 3%
CI-Hospitality 4%
CI-Warehouse 0%
CI-Multifamily 1%
CI-All Other 2%
1 Mixed use buildings shall use the weighted average Additional Percent Savings based on the gross enclosed floor area associated with each building type. Unfinished spaces not submitted in the CS rating system shall use the CS values. Data center space must always be considered “All Other”.
Campus Applicable
No
Internationally Applicable:
No
10/1/2012
LEED Interpretation
Inquiry:
Many projects in Europe are connected to highly efficient district energy systems. However, the EAp2/EAc1 Option 2 guidance provided in the "Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction" (DESv2) document is not well-suited for the complex interconnected district energy systems with multiple fuel sources that are common in Europe. Many European countries already make use of the Primary Energy Factor (PEF) as a means of evaluating district energy performance and building energy performance. Is there an alternative compliance path available to document EAp2/EAc1 credit for the district energy system using the Primary Energy Factor in lieu of the DESv2 Option 2 compliance path?
Ruling:
An alternative EAp2/EAc1 compliance path is available to document the energy performance for complex interconnected district energy systems in Europe using the Primary Energy Factor and the greenhouse gas emissions associated with these systems. The Sweden Green Building Council developed an approved method, "Treatment of European District Energy Systems in LEED" (available November 1, 2012), which may be used in lieu of EAp2 Option 2 of the "Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction" guidance. This compliance path is currently available for projects located in Europe only. Note: The "Treatment of District or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction" (DESv2) is Optional Guidance for LEED 2009 projects. However, project teams that use the guidance must apply all relevant portions of the guidance. The alternative compliance path outlined in the "Treatment of European District Energy Systems in LEED" may only be used to replace Option 2 of the EAp2/EAc1 Energy Modeling Path defined in the DES v2 guidance. Project teams that opt to use the "Treatment of European District Energy Systems in LEED" method must comply with all other applicable requirements of the DES v2 guidance such as those defined for EA Credit 3, EA Credit 4, EA Credit 5, etc. Applicable Internationally; only for projects located in the Europe region.
Campus Applicable
No
Internationally Applicable:
Yes
4/1/2013
LEED Interpretation
Inquiry:
The purpose of this inquiry is to determine if our approach for energy modeling required by credits EAc1 and EAc5 is acceptable. Our project is a 215,800 square foot patient room and administration office addition to an existing hospital. The LEED boundary for the LEED certification includes the new addition only. A boiler and chiller plant provides heating and cooling to the existing hospital and is located within the existing building. The boiler and chiller plant equipment will be demolished and a new, larger boiler and chiller plant will be built within the new attached addition, and will serve both the new addition and existing hospital. The new building addition within the LEED boundary will be served by its own air handling units with hot- and chilled- water coils served from the new mechanical plant which is also within the LEED boundary. We would like to confirm that the following approaches are acceptable: 1) Exclude the existing building which is outside of the LEED boundary from the energy models; and 2) Model the new addition in the budget and proposed design models with a mechanical plant that is appropriately sized for the addition only, and use in the models the efficiencies of the plant equipment that is sized to serve the entire hospital. The equipment sized for the new addition only is in the same size category referenced in ASHRAE 90.1 Section 6 as equipment sized to serve the entire building, so the efficiencies would be the same.
Ruling:
"The proposed modeling approach of sizing the plants within the model for the new addition only is not acceptable. However, since the new mechanical plant located within the LEED Project Boundary is intended to serve both the LEED project building and the remaining existing portion of the building, the plant would effectively be a district thermal energy plant. Therefore, the project team is encouraged to utilize the Treatment of District or Campus Thermal Energy in LEED v2 and LEED 2009 Design & Construction (DESv2.0).
Per the DES guidance, the proposed building heating and cooling are to be modeled using a virtual plant, with average efficiencies that are determined using either the monitoring or modeling methods described in Appendix C. Note that the DES Guidance indicates that when the building housing the thermal energy plant is itself seeking LEED certification, then the project shall treat the DES equipment as downstream equipment for certain prerequisites and credits (including commissioning credits: EAp1 & EAc3, refrigerant credits: EAp3 & EAc4, and measurement and verification: EAc5). However, for the energy model, the district energy equipment shall be modeled as upstream equipment, and the project is recommended to use modeling Option 2, which is allowed even if the minimum point floor from Table 1 is not reached for the project. Although the existing portion of the building does not have to be modeled explicitly, some form of modeling of the district plant and the total load from all buildings (or portions of the building) anticipated to be connected to that plant is required in order to calculate the average efficiency. Generally, some form of load calculation, and identification of predicted load profiles is used when sizing a central plant, and identifying the central plant equipment that will be installed. This data can be used to develop a simple central plant energy model, where the loads from all of the buildings are modeled using the combination of a process load on the plant and a schedule. As stated in Appendix C, average efficiencies may be determined annually, seasonally, monthly, hourly, or for each utility block, as long as the same time scale and method used (either monitoring or modeling) to derive the average efficiency for heating or cooling is consistent for all related district thermal systems that are part of the LEED project. Please note that this means the schedules modeled for this plant model may be as complex as hourly schedules with predicted variations for each hour of the year, or as simple as an annual average load on the district plant assumed for the whole time the plant is anticipated to be operating on an annual basis. For EA Credit 5: Measurement and Verification, clarification should be provided to identify how the energy loads (including thermal loads) for the new addition will be metered separately from the energy loads for the existing building.
Note: This interpretation ruling does not address whether the building addition qualifies with the (Guidance for Certifying Attached Buildings Separately) which is also contained in Version 2 of the LEED 2009 MPR Supplemental Guidance Document.”
Applicable Internationally."
Campus Applicable
Yes
Internationally Applicable:
Yes
7/1/2015
LEED Interpretation
Inquiry:
Is there an adjusted point scale and minimum point threshold where applicable for LEED v2009 projects using ASHRAE 90.1-2010?
Ruling:
**July 1, 2016 update:This ruling has been revised to address the LEED 2009 minimum point requirement released 4/8/2016.**
Yes, LEED v2009 projects that demonstrate compliance using ASHRAE 90.1-2010 may utilize the adjusted point scale as shown in the Related Resource "ASHRAE 90.1-2010 Adjusted Point Scale for LEED v2009 Projects", subject to the following limitations:
• All mandatory provisions associated with ASHRAE 90.1-2010 (or an approved alternative standard) must be met in order for the project to use this compliance path.
• The ID+C thresholds shown are only relevant for projects using the Alternative Compliance Path described in LEED Interpretation 10412 that replaces the LEED 2009 requirements for EAp2, EAc1.1, EAc1.2, EAc1.3, and EAc1.4 with a Performance compliance path. All other ID&C projects would use the standard points available from EAc1.1 through EAc1.4 to comply with the 4-point minimum requirements.
• The CS 2009 EAp2-c1 ACP (http://www.usgbc.org/resources/cs-2009-eap2-c1-acp) may not be used in conjunction with this ASHRAE 90.1-2010 ACP. The project team must either use ASHRAE 90.1-2007 Appendix G with the CS 2009 EAp2-c1 ACP or use ASHRAE 90.1-2010 Appendix G without the CS 2009 EAp2-c1 ACP.
For projects that register on or after April 8th, 2016 and are subject to the mandatory Optimize Energy Performance point minimum:
If the project complies with all LEED v4 Minimum Energy Performance requirements for the relevant LEED v4 rating system, the project shall be considered to satisfy the LEED 2009 EA Prerequisite: Minimum Energy Performance mandatory minimum EAc1 points requirements (applicable for projects registered on or after April 8th, 2016), regardless of number of points achieved when applying this LEED Interpretation. The points documented under EAc1: Optimize Energy Performance shall be as shown in the ASHRAE 90.1-2010 Adjusted Points Scale for LEED v2009 for projects following the Performance Path, and zero for projects following a Prescriptive path.
Campus Applicable
No
Internationally Applicable:
Yes
4/2/2014
LEED Interpretation
Inquiry:
Clarification is requested regarding whether garage demand control ventilation may be modeled for credit. Garage Ventilation is not addressed by ASHRAE 90.1 – 2007, Appendix G, therefore if savings is claimed it must be modeled as an Exceptional Calculation Measure (ECM). Garage demand control ventilation is increasingly becoming standard practice in newly constructed buildings. In order to take credit for this measure as an ECM, it must be demonstrated that the proposed design goes beyond standard practice.
Ruling:
ECMs must be approved by the Rating Authority. As the Rating Authority for LEED projects, the GBCI will accept an ECM for garage demand control ventilation under the following circumstances:
1) Baseline case shall meet the requirements of ASHRAE 90.1-2010, Section 6.4.3.4.5 Enclosed Parking Garage Ventilation. Baseline fan volume shall be based on the minimum required ASHRAE 62.1 parking ventilation rates of 0.75 cfm / square foot. Baseline system fan power shall be calculated at 0.3 watts per CFM.
2) Proposed case shall reflect the actual design. Evidence shall be provided documenting that demand control ventilation strategies are sufficient to automatically detect contaminant levels of concern in parking garages (for example, Carbon Monoxide, Particulates, VOCs, etc. and NO2) and modulate airflow such that contaminant levels are maintained below specified contaminant concentration as identified in ASHRAE 62.1-2010 Addendum d. Evidence shall also be provided that contaminant sensors are placed in space in an appropriate manner for detection of contaminant in question, included in the building commissioning plan upon installation, and then calibrated yearly following installation.
The contaminants of concern that must be monitored may be limited to CO if a narrative is provided justifying how the controls will also help to limit NO2, VOCs and PM2.5 concentrations. The narrative should address how the parking garage minimum exhaust flow rate and/or the minimum fan run time (if applicable) are maintained, and provide clarification that other contaminant levels are expected to remain low based on that design. Note that NO2 would also be expected to be monitored in garages where more than 20% of the vehicles are anticipated to be diesel-fueled.
Note: though it does not need to be addressed specifically in the narrative, the project team must confirm compliance of all ASHRAE 62.1 mandatory measures, including the measure addressing “Buildings with Attached Parking Garages” requiring limitation of vehicular exhaust into adjacent spaces. .
3) If other activities occur in the garage area, the ventilation for these uses shall be in addition to garage vehicle ventilation.
4) Proposed case shall be modeled such that a minimum air flow of 0.05 cfm/square foot is maintained.
5) A narrative shall describe all Baseline and Proposed case assumptions included for this measure, and the calculation methodology used to determine the projected savings. The narrative and energy savings should be reported separately from the other efficiency measures in the LEED Form.
6) No more than a 75% fan energy savings shall be claimed for this measure.
UPDATED on 01/05/18 for rating system version applicability and in Section (2) to clarify that not all contaminants of concern must be continuously monitored.
Campus Applicable
No
Internationally Applicable:
Yes
4/1/2012
LEED Interpretation
Inquiry:
Can we take credit for a demand ventilation system for an automotive service area?Essentially we propose to model the service area in the Baseline Cases at 100% outside air at 1.5 CFM/sq.ft. during occupied periods to meet ASHRAE 62.1. We plan to model the service area in the Proposed Case with typical storage ventilation rate. See rationale below to validate our assumptions.We further propose to model this energy efficiency measure in the standard credit energy models (not as an exceptional calculation) as part of the Baseline and Proposed Cases in order to accurately account for the differences in ventilation load. The differences are based on outside air conditions which change throughout the year and they also impact the supply air unit and fan sizes. The simulation program must size the equipment for the Baseline Case at the peak load and model it use 8760 hours in the year. ASHRAE 62.1 lists a specific minimum ventilation rate for automotive service areas at 1.5 CFM/sq. ft. Ventilation reduction controls are not stated in Ashrae 62.1, nor are they mandated in ASHRAE 90.1-2007. The governing Mechanical Code (International Mechanical Code) optionally permits the use of approved automatic detection devices to control the required ventilation fans and/or make-up air systems. Large make-up air systems providing 100% outside air are still readily available and utilized in order to meet the mandated code. We have utilized the following assumptions for modeling energy usage:Baseline Case - The exhaust ventilation system is modeled to operate at 1.5 CFM/sq.ft. during occupied hours per occupancy schedule. The modeling software automatically sizes the air conditioning system to operate as a 100% outside air system as the total CFM requirement exceeds the design load amount. The unoccupied fan cycle does not include the ventilation and only operates to maintain unoccupied thermostat set point.Proposed Case - The exhaust ventilation system is modeled to be non-operational at any time. We make this assumption based on calculation and witnessed operation at like facilities with the identical control system in place. We have calculated carbon monoxide production based upon maximum estimated daily vehicle round trips through the service area. Eighteen service stalls with an average of 3 vehicles per day and 1 minute round trip drive time yields an estimated total vehicle drive time in the service area to be 54 minutes. The average modern vehicle with catalytic converter produces approximately 150 CFM of exhaust airflow at idle to slow speed containing approximately 1,000 PPM of carbon monoxide. 150 CFM X (0.1%) = 0.15 CFM of carbon monoxide production. The requirement to engage the exhaust ventilation system is 50 PPM of carbon monoxide. The volume of the space is 236,900 cu.ft. and would require 11.845 cu.ft. of carbon monoxide to engage the system. This would require 78.97 minutes of continuous operation without any dilution in a facility this size which exceeds the estimated maximum vehicle operation time of 54 minutes by 30%. The air conditioning equipment serving the area provides 800 CFM outside air and is equivalent to a complete air change twice a day and therefore doubling the daily total required operation time to 157.94 minutes. Operation of vehicles for diagnostic testing is excluded as there is a separate tailpipe extraction system in place to remove all exhaust during testing. Calculations are no substitute for actual conditions. We have interviewed service managers as to the operations of the emergency exhaust system controlled with a CO monitor system. The feed back is overwhelming that the emergency system is never engaged during normal operation. The technicians in these facilities have been trained in the control systems operations and do not desire to have their "conditioned" air purged from the building due to excessive operation of the vehicles within the space.
Ruling:
A project team cannot be awarded credit for demand controlled ventilation in an automotive service area, due to concerns over contaminants, and possible effects on indoor evironmental quality. As there is no current accepted methodology, the potential human health risks outweigh the energy savings.
Campus Applicable
No
Internationally Applicable:
No
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Requirements
3 points mandatory for projects registered on or after April 8, 2016.
Whole building energy simulation (1-24 points)
Demonstrate a percentage improvement in the proposed building performance rating compared with the baseline building performance rating. Calculate the baseline building performance according to Appendix G of ANSI/ASHRAE/IESNA Standard 90.1-2007 (with errata but without addenda1) using a computer simulation model for the whole building project. Projects outside the U.S. may use a USGBC approved equivalent standard2. The minimum energy cost savings percentage for each point threshold is as follows:New Buildings |
Existing Building Renovations |
Points |
|---|---|---|
12% |
8% |
1 |
14% |
10% |
2 |
16% |
12% |
3 |
18% |
14% |
5 |
20% |
16% |
7 |
22% |
18% |
9 |
24% |
20% |
11 |
26% |
22% |
13 |
28% |
24% |
14 |
30% |
26% |
15 |
32% |
28% |
16 |
34% |
30% |
17 |
36% |
32% |
18 |
38% |
34% |
19 |
40% |
36% |
20 |
42% |
38% |
21 |
44% |
40% |
22 |
46% |
42% |
23 |
48% |
44% |
24 |
- Compliance with the mandatory provisions (Sections 5.4, 6.4, 7.4, 8.4, 9.4 and 10.4) in Standard 90.1-2007 (with errata but without addenda1) or USGBC approved equivalent.
- Inclusion of all the energy costs within and associated with the building project.
- Comparison against a baseline building that complies with Appendix G of Standard 90.1-2007 (with errata but without addenda1) or USGBC approved equivalent. The default process energy cost is 25% of the total energy cost for the baseline building. If the building’s process energy cost is less than 25% of the baseline building energy cost, the LEED submittal must include documentation substantiating that process energy inputs are appropriate.
1Project teams wishing to use ASHRAE approved addenda for the purposes of this prerequisite may do so at their discretion. Addenda must be applied consistently across all LEED credits.
2 Projects outside the U.S. may use an alternative standard to ANSI/ASHRAE/IESNA Standard 90.1-2007 if it is approved by USGBC as an equivalent standard using the process identified in the LEED 2009 Green Building Design and Construction Global ACP Reference Guide Supplement.
