Indoor Environmental Quality
Target: 17 points
Indoor air quality is critical to the comfort and longevity of a home. Mold has become a problem in homes as they become tighter.
combustion Venting
All combustion processes in the house are sealed combustion with combustion intake and exhaust air power vented to or from outside the building.
Moisture Control
The central HVAC system has controls to allow it to act in a dehumidification mode.
Distribution of Space Heating and Cooling
Room by room heating and cooling loads were calculated using ACCA Manual J and the room-by-room duct flow rates were calculated using ACCA Manual D. The LEED rater tested the room-by-room flows to assure the HVAC system provided the maximum occupant comfort with the greatest efficiency.
Outdoor Air Ventilation & Local Exhaust
Because the shell of the building is extremely tight a whole building energy recovery ventilation (ERV) system draws air from all bathrooms and the master bedroom. The system operates with a proportional demand controller that assures that the total building air exchange meets the ASHRAE 62.2-2007 requirements. In addition, the controls allow extra timed ventilation from bathrooms as required.
Air Filtering
A MERV 10 filter was installed in the air return system.
Contaminant Control
All permanent ducts were sealed during construction to minimize contamination. The HVAC contractor installed a temporary furnace in order to provide heat during the cold weather construction and avoid filling the ducts with construction dust.
A shoe removal and storage area is located on the screen porch by the primary entrance into the house to minimize carry-in contamination.
A whole house vacuum was installed. It will exhaust directly outdoors.
Radon Protection
The house is located in an EPA Radon Zone 1 area. Potential radon gas is bled off through the gravel bed located below the seal basement floor to a natural draft radon stack that penetrates the house roof. A future electrical connection and location for an in-line fan in the radon stack has been provided in the event of a radon problem.
Garage Pollutant Protection
The garage is detached eliminating potential garage related pollution problems.