Entry Type ID Date Applicable Rating System Primary Credit Inquiry (LIs) Ruling (LIs) Related Addenda/LIs Related Resources Campus Applicable Internationally Applicable Country Applicability Reference Guide (Addenda) Page (Addenda) Location (Addenda) Description of Change (Addenda) "Reference Guide Correction" "100000634" "2009-10-27" "Homes" "EQc7: Supply Air Filtering" "None" "None" "Homes, 2008 edition" "311" "Part B" "[Add ""OR"" between 7.2 and 7.3]" "Rating System Correction" "100000668" "2010-01-01" "Homes" "EQc7: Supply Air Filtering" "None" "None" "Homes, 2008 edition" "95" "Under B. Nonducted HVAC Systems," "there should be an ""OR"" between 7.2 and 7.3." "Reference Guide Correction" "100000635" "2009-10-27" "Homes" "EQc7: Supply Air Filtering" "None" "None" "Homes, 2008 edition" "313" "Column 1, 1st paragraph" """Homes with nonducted HVAC systems that use heat- or energy-recovery ventilators are also exempt, although air filters of some kind are strongly recommended."" change to ""Heat- or energy-recovery ventilators are currently exempt from Prerequisite EQ 7.1, although air filters of some kind are strongly recommended.""" "LEED Interpretation" "1899" "2007-09-05" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "Because system is non-ducted w/ exhaust ventilation, there are no filtering requirements for this project. If however the project chooses to install a MERV 8, 10, or 13 stand alone filtration system (whether ducted or non-ducted) are they entitled to the points?" "A stand-alone filtration system does not qualify for any points in LEED for Homes unless it can be demonstrated that the system is a permanent fixture of the home, and that the filtration system will accommodate the entire home. Updated 10/1/13 for rating system applicability. " "None" "None" "LEED Interpretation" "2162" "2008-05-17" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "For EQ 7.2 and EQ 7.3, is there a requirement related to the size of the air filter housing? If a 1-inch housing is used and a MERV-10 air filter is installed, the occupant will likely replace it with a lower MERV-rated filter. " "There is no requirement related to the size of the air filter housing. Updated 10/1/13 for rating system applicability. " "None" "None" "X" "LEED Interpretation" "2440" "2008-12-08" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "If a home has a separate heating/cooling system and supply ventilation system, are MERV-8 filters required for both? Is it acceptable to have air filters on either?" "MERV-8 filters are required for both the heating and cooling distribution, as well as for any mechanically supplied outside air. Updated 10/1/13 for rating system applicability. " "None" "None" "LEED Interpretation" "2573" "2009-06-13" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "Is exemplary performance credit available for the use of air filters that are MERV-18 or better?" "No - although the use of MERV-18 air filters is welcome, no ID credit should be awarded for their use. Updated 10/1/13 for rating system applicability. " "None" "None" "X" "LEED Interpretation" "2713" "2009-11-18" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "It is very difficult to find a MERV-rated filter for HRVs. Can homes with only HRVs (and non-ducted HVAC) get an exemption for IEQ 7.1 B?" "Heat recovery ventilation (HRV) or energy recovery ventilation (ERV) systems do not need to have MERV-8 air filters. If a home includes a forced-air AHU and an HRV, the AHU must still meet the prerequisite in EQ 7.1. Updated 10/1/13 for rating system applicability. " "None" "None" "LEED Interpretation" "2714" "2009-11-18" "Homes" "EQc7: Supply Air Filtering" "Are hydronic fan coil systems considered forced-air systems, or nonducted systems?" "Hydronic fan coil systems should be considered forced-air systems, and are subject to EA 7.1, section A. Please see EQ 07-13 regarding exemptions for systems with limited ductwork." "None" "None" "LEED Interpretation" "2800" "2010-05-18" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "This project is using the Trane CleanEffects filter. It includes both an electronic and media filter, and it claims to be more effective than a HEPA filter. According to the marketing, it has a ""clean air delivery rate"" that is much higher than 5"" media filter. However, it\'s hard to find a MERV rating. This is a very popular product - how do we handle this?\n\nFurther input from the Green Rater on another project:\nI did some research on the Trane Clean effects and have convinced myself of the following: It is most likely closest to a MERV 15 filter. Below is my reasoning: \nThe test data that they utilize to determine its CADR was done by very well respected scientists. The full study is here:\nhttp://www.trane.com/Residential/Downloads/EHE_study.pdf. If you look at page 23 of that study, they give a chart with particle removal efficiencies for different particle size ranges. You will note that the removal efficiency for all particles between 0.3 microns and 20 microns are above 90%.\n\nThis can then be overlayed on MERV charts. One can be found here: http://www.allergyclean.com/article-understandingmerv.htm. The smallest group of particles (E1 on that chart - 0.3 to 1 micron) are the hardest to filter. A MERV 15 filter is 85-95% efficient at removing them. The clean effects is 90% efficient. A MERV 13 filter (USGBC\'s highest category) is >75%, so we are well over that.\n\nThe only other remaining question is whether the air speed during the test matches up with allowable test speeds for the MERV test. The test allows speeds ranging from 118 to 748 fpm, and you are supposed to report your MERV based on the speed, though you never see that. From digging in the report, the flow rate through the filter was 1273 cfm. I don\'t know the exact cross sectional area of the filter, but it\'s probably about 4 sf. This would be 318 fpm, which is nicely mid-range\nat least. If we bracket worst case, 118 fpm would be a 10.8 sf filter (I know it\'s not that big), and 748 fpm would be a 1.7 sf filter (I know it\'s not that small). " "There is no industry consensus about how to evaluate the performance of electronic air cleaners. Therefore, until or unless ASHRAE or some other independent institution develops a verifiable, repeatable test for both short-term and long-term performance of electronic air cleaners, they cannot be used to satisfy the prerequisite in LEED for Homes, with one exception: if an electronic air cleaner includes a media filter that is MERV rated, this is acceptable. This reverses an earlier project-specific ruling related to Trane CleanEffects filters. Updated 10/1/13 for rating system applicability. " "None" "None" "LEED Interpretation" "2804" "2010-06-07" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "Can a project earn 1 ID point for testing of particulates and VOCs?" "A project may be able to earn 1 ID point for testing of particulates and VOCs, but a detailed ID Request must be submitted outlining a) what tests will be performed; b) who will perform the tests; c) when the tests will be performed; and d) what the relevant thresholds are for each test, and the justification for the threshold. Updated 10/1/13 for rating system applicability. " "None" "None" "LEED Interpretation" "5363" "2009-09-15" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "Does EQ 7.1 apply to non-ducted forced-air systems such as PTACs, mini-split systems, or hydronic fan coil systems?" "As per the language in Section 6.7 of ASHRAE 62.2-2007, non?ducted units and units with less than 10 feet of ductwork, such as PTACs and mini?splits, are exempt from this prerequisite. Updated 10/1/13 for rating system applicability. " "None" "None" "X" "LEED Interpretation" "5403" "2009-08-03" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "The Rating System does not explicitly prohibit bypass systems; should they be disallowed?\n\nThis CIR is based on a project in Canada with a bypass filtration system with a MERV-18 air filter. According to the project team: ""With respect to Rodeo LEED Plantinum Certifications, the HEPA bypass filter works as follows: In continuous fan operation mode the continuous air handler moves aprox. 450 cfm. The Bypass HEPA system operates at 300 cfm. In my 20 years of designing residential mechanical systems, I have never put a HEPA directly into the air stream because it creates too much of a pressure drop. The bypass HEPA has no pressure drop and cleans 100% of the air in the house in less than two passes.""\n" "EQ 7.1 requires ""air filter housings must be airtight to prevent bypass or leakage."" Having a bypass is not acceptable unless both the bypass and primary return include a MERV-8 air filter. If there are multiple returns with different MERV-rated filters, the worst-case MERV rating can be used for the purposes of satisfying EQ 7. If the project wants credit for a weighted average approach, a full explanation of the weighting method must be submitted with some third-party reference supporting the validity of the claim. Updated 10/1/13 for rating system applicability. " "None" "None" "LEED Interpretation" "5411" "2007-02-15" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "How should HEPA filters be treated in EQ 7?" "True HEPA filters should have MERV ratings listed on the equipment that can be used to satisfy IEQ 7. Updated 10/1/13 for rating system applicability. " "None" "None" "X" "LEED Interpretation" "5412" "2007-02-15" "Homes, Mid-rise" "EQc7: Supply Air Filtering" "How should electronic air filters / electronic air cleaners be treated in EQ 7?" "Electronic filters do not have a MERV equivalency, since MERV was developed for mechanical filtration only and there is no consensus based standard for testing electronic filtration efficiency. Filtration characteristics differ substantially between mechanical filtration and electronic filtration, so there is no established MERV equivalency for electronic filtration. Electronic filters or electronic air cleaners cannot be used to satisfy EQ 7 unless the product also includes a MERV-rated media filter. Updated 10/1/13 for rating system applicability. " "None" "None" "X" "LEED Interpretation" "10386" "2014-04-02" "Homes, Mid-rise" "EQ 7: Air Filtering: " "Can international projects use filters rated by CEN Standard EN 779-2002? " "CEN Standard EN 779-2002 rates filtration media. Projects outside the U.S. may use filters with either MERV or CEN ratings. Filters with a class F5 or higher rating are equivalent to a MERV 8 and MERV 10 and filters with a class F7 or higher rating are equivalent to a MERV 13. Additional information on the European Committee for Standardization’s Standard EN 779-2002 can be found on their website: http://www.cen.eu" "None" "None" "X"