A friend of mine says attic fans are helpful only when there is no a c in a home and that all it will do it cool the attic.
Are attic fans necessary with central air.
Rooftop fans and gable fans.
If installed anyway they won t work properly.
Intake vents located at the lowest part of the roof under the eaves allow cool.
Also note that when the ac is on stack effect causes a house to pull air from the attic.
Now if you did have central air conditioning i would tell you not to install an attic fan and here s why.
How does an attic fan work.
If i have central air do i need to replace the broken attic fan.
Because typically attic fans are so strong that not only do they take the hot air out of the attic but they reach down into your house and take the cool air out of the house as well.
Attic ventilation fans offer mechanical ventilation using a fan to draw in cool outside air and force out warm moist air.
I have a shop in my attic for some of my hobbies and it get s very hot in the summer.
Most homes already have some passive attic venting built in.
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 you can install attic fans which will continuously replace the stagnant air with fresh outdoor air preventing your attic from turning into an oven.
This pressure balance improvement and the cooling provided by the air flow are most significant in the case of a leaky ceiling.
Some homes cannot accommodate the amount of attic ventilation that the older traditional style whole house fans require.
There are two basic types of attic fans.
Air is drawn in through the attic fan and air is expelled through the roof vent system to keep your attic cooler and drier preventing ice and moisture issues throughout the winter.
The ventilation that controls moisture from condensation and regulates the temperature in your attic relies on air circulation.
Cool air enters the attic through soffit vents in the eaves.
Oh an attic fan will do that.
I have large attic with ridge vents and screened vents at either end of the attic to maintain air flow.
Three years ago i replaced my hvac system and updated my central air.
In a properly designed passive system air enters through the soffit.
Can i put a small swamp cooler or ventless a c unit up there to cool it only to use while i am in my shop maybe an hour or two a couple times a week.
Exhausting moderate amounts of attic air as solar fans do can counteract this reducing infiltration my calculations show it to be about right for a vented attic but either do the calculations or measure the pressures.
I am thinking that in addition to cooling the attic the attic fan.
Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
Building codes often require about 1 foot of attic ventilation for every 750 cfm airflow.
