This credit requires compliance with a varied group of items that cumulatively help keep pollutants out of the indoor air. These requirements include self-closing doors on janitors' closets, MERV 13 filtration on mechanical equipment, and entryway trackoff systems. Compliance will require the coordination of team members—including the mechanical engineer, architect, plumbing engineer, and contractor—and also impact project design and operations. The basic requirements are:
- Permanent entryway walk-off systems at least 6 feet long at all regularly used, entryways that are directly connected to the outdoors including, exterior-to-interior entrances and entrances from covered parking garages. (Roll-out mats are acceptable only if maintained on a weekly basis.)
- Designated exhaust of all hazardous gas and chemical use areas—including garages, housekeeping, janitors’ closets, laundry areas, science labs, art rooms, workshops, copy and printing rooms, and prep rooms.
- An exhaust rate of 0.5 CFM/SF, with no air recirculation, in hazardous gas and chemical use areas.
- Self-closing doors on all spaces outlined above.
- Deck-to-deck partitions or hard-lid ceilings on all spaces outlined above.
- MERV 13 filtration for all return and outside air intakes in mechanically ventilated spaces that are regularly occupied.
Keep dirt out!
In addition to tobacco smoke, covered in EQp2, one of the greatest sources of indoor pollutants is the dirt and other contaminants brought into buildings on people’s shoes. This material is tracked through the building interior, increasing the need and frequency for cleaning, and the wear on interior finishes. Dust can also be introduced into ventilation systems and distributed throughout a building, negatively effecting indoor air quality.
Fairly straightforward, but some pitfalls
While it takes a lot of coordination to meet the many credit requirements, this is generally a low-cost credit. The most significant impact may come if MERV 13-compatible air-handling equipment is not initially specified, as redesigning mechanical systems can be costly. MERV 13 filtration results in an energy-use trade-off. While MERV 13 filters offer a greater level of air filtration and, consequently, increased indoor air quality, they also increase resistance to airflow and fan energy loads. If you can separate space conditioning from ventilation and use radiant systems for all or most of the space conditioning, you can minimize this energy penalty.
Multifamily and hotel
Multifamily residential and hotel projects may have difficulty achieving this credit due to the MERV 13 filtration requirement. These projects often do not have base-building HVAC systems; they use PTACs instead, which generally cannot be fitted with MERV 13 filters. If a project has forced air systems and MERV-13 filtration is not used, then you cannot pursue or achieve this credit. Naturally ventilated buildings do not have to meet the MERV 13 filtration requirement, as air filtration will not be part of system design.