Rating System

LEED BD+C: New Construction, LEED O+M: Existing Buildings, LEED ID+C: Commercial Interiors, LEED BD+C: Core and Shell, LEED BD+C: Schools

Rating System Version

v3 - LEED 2008, v2 - Schools 2007, v2 - LEED 2.2, v2 - LEED 2.0

Inquiry

Our project is a new 7-story, 120-unit, residential building for retired seniors in Massachusetts. The apartments will have operable windows in the living rooms and bedrooms, with openable areas significantly greater than 4% of the floor area, and kitchens that are permanently open to the living rooms. However, some apartments will be deeper than 25 feet. (The worst case scenerios would likely be 29 feet deep for a non-corner unit or 38 feet deep for a corner unit.) Furthermore, some units will have interior bathrooms and walk-in closets that are not permanently open (as defined by ASHRAE 62.1 2004) to the spaces with windows. The living units will have heat pumps with air handlers that offer heating, cooling, or fan-only mode. The air handlers will intake return air, rather than outside air, but the air intake will be within 25 feet of the operable windows, meaning a portion of the air would be fresh when the windows are open. The air handlers would then distribute ducted supply air to each major room, not including bathrooms and walk-in closets. Also, the public corridors will be positively pressurized providing make-up air to the apartments via door under-cuts. The bathrooms will have occupant-controlled exhaust fans. 1. Is it possible that this design as-is meets the outdoor air ventilation requirements of ASHRAE 62.1 2004? If so, with such a complex air delivery model, how do we perform the calculations, if any, to prove this for LEED? 2. If it sounds like our design does not meet ASHRAE 62.1 2004, could either of the following solutions bring us into compliance? And again how would we perform the calculations, if any? a. Installing occupant-controlled paddle fans on the ceilings of the rooms with windows. b. Installing continuous bathroom exhausts (or bathroom exhausts on a timer) to draw fresh air deeper into the space. The bathrooms are usually located at the furthest points from the operable windows. 3. If none of the above solutions sound like they meet ASHRAE 62.1 2004, do you have any suggestions other than making the living units less than 25 feet deep? By the way, we would like to keep the units negatively pressurized with respect to the public corridors to meet the Environmental Tobacco Smoke prerequisite. One final question. Under ASHRAE 62.1 2004 are apartment kitchens required to be exhausted to the outdoors? If so, is there any way the bathroom exhausts could satisfy this requirement?