Exhaust Ventilation Systems

Teral-aerotech Exhaust ventilation systems work by depressurizing the building and reducing the inside air pressure below the outdoor air pressure, they extract indoor air from a house while make-up air infiltrates through leaks in the building shell and through intentional, passive vents. Exhaust Ventilation System.

Teral-aerotech Exhaust ventilation systems are most applicable in cold climates. In climates with warm, humid summers, depressurization can draw moist air into building wall cavities, where it may condense and cause moisture damage. Teral-aerotech Exhaust ventilation systems are relatively simple and inexpensive to install. Typically, an exhaust ventilation system is composed of a single fan connected to a centrally located, single exhaust point in the house.

A preferable option is to connect the fan to ducts from several rooms (especially rooms where pollutants tend to be generated, such as bathrooms). Adjustable, passive vents through windows or walls can be installed to introduce fresh air rather than rely on leaks in the building envelope. However, passive vents may be ineffective because larger pressure differences than those induced by the ventilation fan may be needed for them to work properly.

Teral-aerotech ventilation exhaust fans installed in the bathroom but operated continuously represent an exhaust ventilation system in its simplest form. One concern with exhaust ventilation systems is that they may draw pollutants, along with fresh air, into the house. For example, in addition to drawing in fresh outdoor air, they may draw in the following:

• Radon and molds from a crawlspace
• Dust from an attic
• Fumes from an attached garage
• Flue gases from a fireplace or fossil fuel–fired water heater and furnace