However if your attic has blocked soffit vents and is not well sealed from the rest of the house attic fans will suck cool conditioned air up out of the house and into the attic.
Attic fans do they work.
Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
Any home with an attic space walk in or crawl space that is unheated in the winter needs an attic fan to expel dollar robbing heat collected during summer days.
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.
Some can have manual switches while others use a thermostat to turn them on and off automatically.
How does an attic fan work.
The problem with this design as argued by energy professionals is that attic fans also pull the conditioned air from your home into the attic.
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 fans exhaust hot air from your attic to the outside.
Attic ventilation fans help cool air your attic by pushing out the stifling hot air from inside the attic and bringing in cool air from outside.
This action cools the area down and gets rid of any excess humidity.
Once the warm air is out intake vents pull cool and dry air from your living space into the attic.
It allows hot air to escape in the summer and can also help reduce the chances of ice damage in the winter by allowing a natural flow of outdoor air to ventilate the attic.
Intake vents located at the lowest part of the roof under the eaves allow cool.
This is where an attic fan can help.
Attic fans come with different models.
A mechanical fan working in an attic space equipped with adequate ventilation openings can move hot air out and increase the flow of air through the attic.
When the attic gets too hot it turns on automatically.
Ideally this will lower the high temperatures that have built up in your attic.
The benefits of an attic fan.
This air is then exhausted through the fan to the outside.
It fits in with the shingles and is water proof.
This pressure balance improvement and the cooling provided by the air flow are most significant in the case of a leaky ceiling.
How an attic fan works.
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.
While a simple vent is sometimes used to allow for the passive flow of air it s also possible to add a powered attic fan commonly called an attic power ventilator.
Attic fans are intended to cool hot attics by drawing in cooler outside air from attic vents soffit and gable and pushing hot air to the outside.