Attic fans and whole-house fans are two very different pieces of equipment that serve entirely different purposes in a building. These differences are often a point of confusion among consumers, since some contractors use the terms interchangeably. The purpose of an attic fan is to regulate the temperature in the attic of a building, while a whole-house fan is meant to cool the entire building.
An attic fan is an exhaust fan for the attic, installed at roof level or at a gable end. It works throughout the day to transfer heat from the attic to the outdoors. As that heat is exhausted by the attic fan, fresh, cooler air is drawn in through roof vents, preventing the accumulation of excessive heat in the attic space through a more efficient ventilation process. This does have an indirectly positive effect on home cooling, however, since without the ventilation provided by the attic fan, the heat in the attic can radiate down into your living spaces.
A whole-house fan, on the other hand, is designed to provide more efficient ventilation to the entire building. It is installed in the ceiling of a building to draw hot air within the building into the attic to be forced out through the roof vents. As that hot air is exhausted, cool air is drawn in through open windows. These fans are used to provide natural cooling within the building when outdoor air is cooler that the indoor temperature and can significantly reduce the need for air conditioning.
Attic fans, as part of an efficient attic ventilation system, can significantly reduce the heat load in a building, enhancing energy efficiency. However, if the building is not properly insulated, attic vents are obstructed or there aren’t enough of them to create sufficient air flow, an attic fan may work against energy efficiency by drawing conditioned air from the occupied space into the attic. For this reason, it’s important to have your attic fan installed by a qualified HVAC professional.
For more information on attic fans, whole-house fans or any other home comfort concerns, please contact us at NisAir Air Conditioning & Heating. Family owned and operated since 1973, we take pride in providing excellent service to our valued customers throughout Martin, Palm Beach and Indian River counties.