The decision to use house ventilation is typically motivated by concerns that natural ventilation won't provide adequate air quality, even with source control by spot ventilation. Whole-house ventilation systems provide controlled, uniform ventilation throughout a house. These systems use one or more fans and duct systems to exhaust stale air and/or supply fresh air to the house.
There are four types of systems:
1.Exhaust ventilation systems work by depressurizing the building and are simple and inexpensive to install.
2.Supply ventilation systems work by pressurizing the building, and are also relatively simple and inexpensive to install.
3.Balanced ventilation systems, if properly designed and installed, neither pressurize nor depressurize a house. Rather, they introduce and exhaust approximately equal quantities of fresh outside air and polluted inside air.
4.Energy recovery ventilation systems provide controlled ventilation while minimizing energy loss. They reduce the costs of heating ventilated air in the winter by transferring heat from the warm inside air being exhausted to the fresh (cold) supply air. In the summer, the inside air cools the warmer supply air to reduce ventilation cooling costs.
Ventilation is not an effective cooling strategy in hot, humid climates where temperature swings between day and night are small. In these climates, however, natural ventilation of your building (often required by building codes) will help to reduce your use of air conditioning, and attic fans may also help keep cooling costs down.