The downside of attic ventilation fans.
Do i need a solar attic fan.
If your attic space is over 1 800 square feet you will need enough solar fans to move 8 000 cfm.
You will probably need two solar attic fans to get the results you want.
How an attic fan works.
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.
The ventilation that controls moisture from condensation and regulates the temperature in your attic relies on air circulation.
Purchasing an electric or solar attic fan may not provide the savings that homeowners expect.
These fans are designed to remove excess heat from your attic which in theory is supposed to lessen the load on the air conditioning in your home.
That means you will need to double up your investment in this area.
But they re much easier to install since no wiring is needed.
To determine the number of cubic feet per minute needed for a power vent fan multiply the number of square feet in your attic by 0 7.
Intense sunlight can create heat faster than one or two small fans can cool an area.
If a cloud blocks the sunlight the fans slow or stop.
An attic fan is installed on the slanted side of your roof or on one of the gable sides of your attic.
For the attic fans to work at peak efficiency they need to be on a south facing roof slope if you live in the northern hemisphere.
Attic fans exhaust hot air from your attic to the outside.
Because what happens is attic fans are so strong that they actually reach down into the conditioned space of your house and they do that by using the wall cavities and where the outlets and pipes come through the walls as places where they draw air from the inside of your house it.
Solar powered attic vent fans usually don t move as many cubic feet of air per minute cfm as hardwired fans.
You need that amount of air if not more to get any sort of cooling benefit from the fans.
Do you need an attic fan if you have a ridge vent.
Good insulation reduces fan effectiveness.
Adding roof ridge vents can reduce summer air conditioning costs prevent roof mildew and rot and keep your roof in better shape longer.
In a properly.
Because solar attic fans operate with a lower power output they are unable to move as much air as some of the other options that are available.