How Many Attic Fans Should I Have

You place the fans on the gable walls of your attic.

How many attic fans should i have.

Attic ventilation fans whether hard wired or powered by their own solar panels seem like a low cost and effective way to help keep your house cool. Dwight barnett is a certified master inspector with the american. For particularly dark or steep roofs we recommend a slightly higher rating. Powered attic ventilator fans designed to cool your attic by drawing the hot and humid air out of the attic and bring in a flow of chilly air from outside.

These include the following. The downside of attic ventilation fans. Also the devices have benefits like protecting your roof from damage which might be brought about by the heat and humid moving around the attic thus damaging the insulations and. The air being exhausted must be replaced by outside air drawn through vents under the eaves in the soffit.

Attic fans reduce heat dramatically. Now take that number and divide it by 750. Any whole house fan that you buy should have this figure listed somewhere on the packaging. Attic vent fans are commonly rated from 800 to 1 600 cfm making one fans suitable for attics of up to around 2 200 square feet.

Hvi recommends a ratio of 60 to 40 for soffit ventilation to gable or ridge ventilation. Attic fans perform this ventilation by pushing hot air out into the environment while also pulling fresh cool air into the attic. As a general rule unless a homeowner has a highly qualified person to evaluate their house i think its safe to say that attic fans should be avoided. So if your fan is rated at 1500 cfm you will need about two feet of totally open space in your attic.

Powered attic ventilators should provide at least 10 air changes per hour. Like so many other plug in solutions attic fans certainly have the potential to make things worse rather than better. Attic x 0 7 700 cfm minimum fan rating add an additional 20 cfm x 1 20 if you have a steep roof and 15 cfm x 1 15 for a dark roof. The result is a cooler attic space with plenty of air exchange.

With square foot living space at a premium many homeowners turn to their attics for a little extra room. With an attic fan many attics have a temperature that is the same as the outside air or just a few degrees warmer. If the home already has a fan roof vents or gable vents these should be blocked and sealed from the attic side of the home. Multiplying the total square footage of the attic by 0 7 will provide the rate required.

Your article does a great job of outlining how this happens. When the attic becomes part of the home to be heated and cooled open wall gable vents and.