Attic Fans-Do They Work?

Attic fans can be used to cool your liv­ing space any time it is cool­er out­side than inside your home.  Attic fans pull air in through an open win­dow or door while push­ing hot air out of your home through attic vents.

Ven­ti­la­tion fans are designed to cool the attic with the inten­tion of sav­ing ener­gy and the roof.  Because hot air is full of mois­ture, all the water hang­ing out in your attic is caus­ing con­den­sa­tion to build up.  Excess heat and con­den­sa­tion caus­es major dam­age to roofs and roof­ing materials.

When you use a fan, ener­gy is saved by reduc­ing the use of the air con­di­tion­er in the home.  You can use your air con­di­tion­ing and whole house fan at the same time.  How­ev­er, if it is cool­er out­side than inside it does­n’t make sense to use your air conditioning.

Some would debate the effec­tive­ness and safe­ty of attic fans.  Line-pow­ered fans have been shown in stud­ies to actu­al­ly cost more to oper­ate than the sav­ings they pro­duce.  Solar-pow­ered fans don’t draw near­ly as much air as line-pow­ered fans.  One par­tic­u­lar study found that by installing two solar attic fans in a 1000 square foot house saved about $50.00 per year in ener­gy costs.

A solar fan oper­ates com­plete­ly off solar ener­gy.  It pulls the out­side air in through exist­ing sof­fit vents.  It extracts the hot, humid air up through the fan and cre­ates a con­stant exchange of air in your attic.  Most attic fans oper­ate with a ther­mo­stat that auto­mat­i­cal­ly turns the fan on and off based on a tem­per­a­ture the home­own­er sets.  It is usu­al­ly rec­om­mend­ed to use a set­ting of 100–110 Fahrenheit.

Installing an attic fan may require a roofer to cut and seal the roof or an elec­tri­cian to con­nect a solar pow­ered fan.  If new vents are need­ed you may have to hire a carpenter.

Most fans will last 10–15 years.  Once it reach­es that age it may require motor replace­ment.  Wiring and ther­mo­stat issues can be fixed by an elec­tri­cian or oth­er type of HVAC contractor.

Attic fans can cost between $300-$600 installed.  You can con­tact your local HVAC con­trac­tor for more information.