Energy Efficiency - Fresh Air Supply
Pierce Homes Energy Program

Since all Pierce Energy Efficient homes are tightly sealed for outside air infiltration, we design fresh air systems to dilute/exhaust inside air contaminants to insure a more healthy indoor air quality.  Indoor contaminants and odors are generated from cooking, fabric and wood outgassing, insectides and other cleaning materials.  A balanced air exchange system is designed for each home, where fresh make-up air is provided to prevent the home from reaching a negative pressure state.   The following photo shows the device that controlls both the air handler fan as well as a damper in the return air circuit.



This separate control system is installed to cycle the air handler fan on the HVAC unit periodically to insure an adequate supply of filtered fresh air.  This control system is designed to only cycle the air handler fans when the evaporator coils in the air-conditioning system have dried from the previous run cycle.  This is to prevent additional humidity from being introduced into the air-conditioned space.  The photo below shows the electrically activated damper in the return air circuit that modulates the fresh air coming into the HVAC unit and which is controlled by the controller shown above.

The above photos show how fresh air is introduced into each Pierce EFL home.  Means are also provided, as shown in the photo below, for exhausting stale and polluted air from the home, typically in the kitchen, utility room and each bath room. All exhaust fans in Pierce EFL homes are vented to the exterior of the home and designed so the home remains under positive pressure to minimize exterior pollutants from being drawn into the home and to prevent the backdrafting of combustion appliances.