Do Attic Fans Work Well

Energy professionals will tell you that they do more harm than good.

Do attic fans work well.

As a certified licensed home inspector it is not correct to say too much ventilation is bad for an attic unless rain moisture is getting in. Attic ventilation fans help cool air your attic by pushing out the stifling hot air from inside the attic and bringing in cool air from outside. Theory behind attic fans is they work on the principle of drawing hot air out of the attic and pushing it outside through the gable or roof levels. Strong attic fans can actually back draft furnaces or water heaters by pulling combustion gases out of their burnersand into the home.

Cold air is drawn in from outside through the soffit vents or roof. Much of that heat then conducts downward and finds its way into the house. Do not use mechanical means electric attic fans. This prevents hot air from seeping into your home and driving up the temperature in the living space which reduces the load on your air conditioner.

But the house is incredibly comfortable. Using a fan to blow hot air out of the attic doesn t address the radiant heat flow from the roof to the attic floor. Powered attic ventilators or attic fans just as they sound are designed explicitly for placing or installing in the attics. Trying to solve the heat gain problem in your attic by using a fan is like lying out at the beach with a fan blowing over you and thinking you re not going to get a sunburn.

Venting a homes attic is a very important best building practices will say 50 at the ridge and 50 at the soffits unobstructed. Attic fans are intended to cool hot attics by drawing in cooler outside air from attic vents soffit and gable and pushing hot air to the outside. Manufacturers of attic fans as well as hvac companies will tell you otherwise. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

Intake vents located at the lowest part of the roof under the eaves allow cool. We do have very low electric bills despite the attic fans running from noon to midnight on hot days thermostat controlled and the tamarack running all night as well. A retrofit example that works. Principal research scientist danny parker of the florida solar energy center has tested solar attic fans and says the gable end models work the best since they move considerably more air than roof mounted mushroom top units you can install pv fans yourself if you have good carpentry skills but it s not necessarily an easy job.

Here is some information so you can decide whether an attic fan is right for your home. Good attic ventilation is excellent for preventing moisture and condensation but it is usually not enough for cooling in the summertime.