The project intends to meet the permanent entryway system and exhaust system requirements of the credit criteria. The project is requesting an interpretation of the acceptability of the method proposed to meet the MERV 13 filtration requirement. The project HVAC system is a dual path HVAC system: Outside air for ventilation is provided by 100% fresh air air-handlers with heat recovery from exhaust air. These air handlers will be equipped with MERV 13 filtration or better as well as other features for achieving high efficiency. Zone conditioning will be provided by fan coils receiving a mixture of return air from the space and fresh air from the air handlers described above. In this respect, the fan coils provide a similar function to that of fan powered terminal units on a conventional variable air volume system and similar to that system, MERV 13 filtration is not possible on the zone fan coil level. The design team believes that the design meets the intent of the credit for filtration since all outside air introduced into the building will be filtered to the high standard of MERV 13.
The CIR inquiry indicates that the project receives 100% of its outside air through air handling units that are equipped with MERV 13 filtration, as required by EQc5. Additional fan coil units are located within the building to provide supplemental zone conditioning. The fan coil units supply a combination of the minimum ventilation outdoor air plus air recirculated from the room. Since the fan coil units recirculate room air, they must have MERV 13 filters, which are available on the market. Therefore, the design, as described, does not appear to meet the intent of the credit.
**Updated January 1, 2014
NOTE: UPDATED CREDIT LANGUAGE FOR 2009 STATES THAT "PARTICLE FILTERS OF AIR CLEANING DEVICES SHALL BE PROVIDED TO CLEAN THE OUTDOOR AIR AT ANY LOCATION PRIOR TO ITS INTRODUCTION TO OCCUPIED SPACES". REQUIREMENT FOR FILTRATION ON RETURN AIR IS NO LONGER APPLICABLE TO ANY VERSION OR ANY RATING SYSTEM.