Do Attics Need Fans

That s an opening right.

Do attics need fans.

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. Intake vents located at the lowest part of the roof under the eaves allow cool. Much of that heat then conducts downward and finds its way into the house. Electric attic fans however often increase energy consumption and cancel out any savings unless the attic is not insulated at all.

And if your attic is depressurized it s going to want to suck air up from anywhere it can find. Open your windows before you turn on the fan. 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 s that air conditioned air and it ll pull it right up into the attic and exhaust it outside. Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation.

But the problem with attic fans is that your house has all types of little gaps in it that connect the attic to the inside that can hinder attic ventilation. In the late evening or early morning the fan is turned on to exhaust hot air from the house. The main work of an attic fan is to regulate the heat level of the attic by removing hot air out of the attic and pushing it outside providing needed ventilation. Cooler outdoor air enters through open windows lowering the indoor temperature.

Ventilation fans or powered attic ventilators are designed to cool the attic pushing out the hot attic air and rushing in a flow of cool outside air. That said air resistance and interference such as vent grates reduces the area of true ventilation. Think about the framed wall and the outlet for example. A whole house fan is usually installed on the attic floor near the center of your house.

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. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.