Table 1. Minimum ventilation area
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LEED CREDIT
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Credit language
© Copyright U.S. Green Building Council, Inc. All rights reserved.
The indoor air quality procedure defined in ASHRAE Standard 62.1–2010 may not be used to comply with this prerequisite.
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Continuous ventilation |
Intermittent ventilation |
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Single-sided |
0,35 m² / person |
1,05 m² / 10 m² room area |
Cross-ventilation |
0,2 m² / person |
0,6 m² / 10 m² room area |
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Learn more about The Cost of LEED v4 »Frequently asked questions
My building has 80 AHUs providing ventilation to building spaces. Do I have to do the ventilation calculations and conduct outdoor air measurements for each one? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
What if after our Preliminary Review we have to revise the ventilation rate procedure calculations and find that we need to make corrections to the system in order to meet the prerequisite? Can we redo the outside air testing after making corrections? Would we need to update the performance period for all credits accordingly? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
What if our systems do not meet the required outside air when systems are tested at worst-case conditions? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
Our building has a single fan that supplies outside air to multiple AHUs. Do we need to perform outside air testing at the supply fan or at all AHUs? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
We have a VAV system where single AHUs serve multiple zones. Do we need to take outside air measurements at each VAV box? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
What happened to the IEQ Space Matrix that was available to version 2009 projects? What should I reference to determine how spaces in my building should be categorized for this prerequisite? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
How do I find whether my project is located in a non-attainment area for particulate matter or exceeds the prerequisite ozone requirements? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
The outdoor air intake for our ventilation system is not accessible, and it’s not possible to measure the outdoor airflow directly. How can we determine the outdoor airflow for this system? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
Our system cannot provide enough outdoor air to meet ASHRAE 62.1-2010 due to design limitations. How much outdoor air must we provide to meet Case 2 instead? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
Addenda
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May we use a more current version of ASHRAE 62.1 and ASHRAE 55?
Yes, for ASHRAE 62.1, LEED v4.1 projects may use ASHRAE 62.1-2019 or ASHRAE 62.1-2020 in lieu of ASHRAE 62.1-2016 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Enhanced Indoor Air Quality Strategies. The same standard must be used for both credits.
LEED v4 projects may use ASHRAE 62.1-2013, ASHRAE 62.1-2016, ASHRAE 62.1-2019, or ASHRAE 62.1-2020 in lieu of ASHRAE 62.1-2010 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Enhanced Indoor Air Quality Strategies. The same standard must be used for both credits.
LEED 2009 projects may use ASHRAE 62.1-2010, ASHRAE 62.1-2013, or ASHRAE 62.1-2016, ASHRAE 62.1-2019, or ASHRAE 62.1-2020 in lieu of ASHRAE 62.1-2007 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Increased Ventilation. The same standard must be used for both credits.
For ASHRAE 55, LEED v4.1 projects may use ASHRAE 55-2020 in lieu of ASHRAE 55-2017 for EQ Credit Thermal Comfort.
LEED v4 projects may use ASHRAE 55-2013 in lieu of ASHRAE 55-2010 for EQ Credit Thermal Comfort.
LEED 2009 projects may use ASHRAE 55-2010 or ASHRAE 55-2013 in lieu of ASHRAE 55-2004 for EQ Credit Thermal Comfort- Design.
**Updated 7/10/2020 to include ASHRAE 62.1-2016 and ASHRAE 62.1-2019 as applicable standards.**
**Updated 7/25/2023 to update to include LEED v4.1 and ASHRAE 2022/2020 standards**
We are working to certify a 30 year old office tower. While we have copies of original mechanical design drawings and schedules, the building systems have experienced a number of retrofits over the years, and the as-built documentation is sparse. The ASHRAE 62.1-2007 ventilation rate procedure calculations for multiple zone systems rely on precision understanding of the ventilation zones (areas served by each terminal unit), zone airflow rates and VAV terminal unit minimum flow settings, and the system airflow rates. The extent to which the building must be surveyed and the systems tested to provide a high level of confidence in the VRP calculation inputs would be onerous and cost prohibitive. Without this survey information, the inputs to the calculator rely heavily on engineering judgement.
Can we instead use this simpler ventilation rate procedure calculation, to determine how much outdoor air should be supplied to the building?
Ventilation required in IP units = (0.06 cfm/sf x gross building area (in sf) ) + ( 5 cfm per person x building occupancy )
and ventilation required in SI units: = (0.3 L/s*m2 x gross building area (in m2)) + (2.5 L/s per person x building occupancy)
Yes, for office building projects, the proposed simplified calculation may be used. Other project types should use the appropriate Rp value from 62.1-2007, Table 6-1. Projects with multi-zone systems utilizing this simplified calculation approach should provide a supplemental narrative and may document the ventilation calculations as single zone systems within the EQ Minimum IAQ Performance Calculator.
The measured outdoor airflow rate for the building should be equal to or greater than the value calculated.
**Update for 1.11.19
A separate calculation must be performed for each air handling unit serving the project.
Documentation toolkit
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© Copyright U.S. Green Building Council, Inc. All rights reserved.
The indoor air quality procedure defined in ASHRAE Standard 62.1–2010 may not be used to comply with this prerequisite.
|
Continuous ventilation |
Intermittent ventilation |
---|---|---|
Single-sided |
0,35 m² / person |
1,05 m² / 10 m² room area |
Cross-ventilation |
0,2 m² / person |
0,6 m² / 10 m² room area |
In the end, LEED is all about documentation. LEEDuser’s Documentation Toolkit, for premium members only, saves you time and helps you avoid mistakes with:
My building has 80 AHUs providing ventilation to building spaces. Do I have to do the ventilation calculations and conduct outdoor air measurements for each one? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
What if after our Preliminary Review we have to revise the ventilation rate procedure calculations and find that we need to make corrections to the system in order to meet the prerequisite? Can we redo the outside air testing after making corrections? Would we need to update the performance period for all credits accordingly? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
What if our systems do not meet the required outside air when systems are tested at worst-case conditions? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
Our building has a single fan that supplies outside air to multiple AHUs. Do we need to perform outside air testing at the supply fan or at all AHUs? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
We have a VAV system where single AHUs serve multiple zones. Do we need to take outside air measurements at each VAV box? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
What happened to the IEQ Space Matrix that was available to version 2009 projects? What should I reference to determine how spaces in my building should be categorized for this prerequisite? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
How do I find whether my project is located in a non-attainment area for particulate matter or exceeds the prerequisite ozone requirements? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
The outdoor air intake for our ventilation system is not accessible, and it’s not possible to measure the outdoor airflow directly. How can we determine the outdoor airflow for this system? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
Our system cannot provide enough outdoor air to meet ASHRAE 62.1-2010 due to design limitations. How much outdoor air must we provide to meet Case 2 instead? The answer to this question is available to LEEDuser premium members. Start a free trial » (If you're already a premium member, log in here.) |
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---|---|---|
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May we use a more current version of ASHRAE 62.1 and ASHRAE 55?
Yes, for ASHRAE 62.1, LEED v4.1 projects may use ASHRAE 62.1-2019 or ASHRAE 62.1-2020 in lieu of ASHRAE 62.1-2016 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Enhanced Indoor Air Quality Strategies. The same standard must be used for both credits.
LEED v4 projects may use ASHRAE 62.1-2013, ASHRAE 62.1-2016, ASHRAE 62.1-2019, or ASHRAE 62.1-2020 in lieu of ASHRAE 62.1-2010 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Enhanced Indoor Air Quality Strategies. The same standard must be used for both credits.
LEED 2009 projects may use ASHRAE 62.1-2010, ASHRAE 62.1-2013, or ASHRAE 62.1-2016, ASHRAE 62.1-2019, or ASHRAE 62.1-2020 in lieu of ASHRAE 62.1-2007 for EQ Prerequisite Minimum Indoor Air Quality Performance and EQ Credit Increased Ventilation. The same standard must be used for both credits.
For ASHRAE 55, LEED v4.1 projects may use ASHRAE 55-2020 in lieu of ASHRAE 55-2017 for EQ Credit Thermal Comfort.
LEED v4 projects may use ASHRAE 55-2013 in lieu of ASHRAE 55-2010 for EQ Credit Thermal Comfort.
LEED 2009 projects may use ASHRAE 55-2010 or ASHRAE 55-2013 in lieu of ASHRAE 55-2004 for EQ Credit Thermal Comfort- Design.
**Updated 7/10/2020 to include ASHRAE 62.1-2016 and ASHRAE 62.1-2019 as applicable standards.**
**Updated 7/25/2023 to update to include LEED v4.1 and ASHRAE 2022/2020 standards**
We are working to certify a 30 year old office tower. While we have copies of original mechanical design drawings and schedules, the building systems have experienced a number of retrofits over the years, and the as-built documentation is sparse. The ASHRAE 62.1-2007 ventilation rate procedure calculations for multiple zone systems rely on precision understanding of the ventilation zones (areas served by each terminal unit), zone airflow rates and VAV terminal unit minimum flow settings, and the system airflow rates. The extent to which the building must be surveyed and the systems tested to provide a high level of confidence in the VRP calculation inputs would be onerous and cost prohibitive. Without this survey information, the inputs to the calculator rely heavily on engineering judgement.
Can we instead use this simpler ventilation rate procedure calculation, to determine how much outdoor air should be supplied to the building?
Ventilation required in IP units = (0.06 cfm/sf x gross building area (in sf) ) + ( 5 cfm per person x building occupancy )
and ventilation required in SI units: = (0.3 L/s*m2 x gross building area (in m2)) + (2.5 L/s per person x building occupancy)
Yes, for office building projects, the proposed simplified calculation may be used. Other project types should use the appropriate Rp value from 62.1-2007, Table 6-1. Projects with multi-zone systems utilizing this simplified calculation approach should provide a supplemental narrative and may document the ventilation calculations as single zone systems within the EQ Minimum IAQ Performance Calculator.
The measured outdoor airflow rate for the building should be equal to or greater than the value calculated.
**Update for 1.11.19
A separate calculation must be performed for each air handling unit serving the project.