Ventilation System

The building envelope is the first place to start in building an energy-efficient home or building. The House on Third Street employs a building system designed to eliminate air infiltration. While this prevents cold and heat from entering the structure, it also prevents the fresh air we need to breathe from entering as well. 

To compensate of this, an energy efficient heat recovery ventilation system (1) is used to bring fresh air into the home. The equipment uses the air being exhausted from the home to warm the fresh air being brought into the home.

Because the heat exchange is only about 50% efficient, during the winter the incoming air will typically be cooler than the interior air temperature. If the ventilation system were to ran all the time, there would be a constant flow of cooler air into the home and the heating system would have to operate longer to compensate for it, even when we are not home.

To avoid this, a C02 switch, which is located on the living room wall, monitors the CO2 levels in the home and automatically turns the ventilation system on and off. Humans produce CO2, which means when we aren’t home, no CO2 is being produced and the systems doesn’t operate. When we are home the system only operates when the CO2 levels rise above 1880 parts per million, and turns off when CO2 levels are reduced to about 1300 parts per million.

To go a step further a Whole House HEPA Filter sytem (2) is used to remove allergens and bacteria from the air before the air enters the heat exchange ventilation system.

Note: