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.
Do i need a solar attic fan.
An attic fan is installed on the slanted side of your roof or on one of the gable sides of your attic.
This fan moves 1 000 or more cubic feet of air per minute creating low pressure in your attic.
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.
Attic fans exhaust hot air from your attic to the outside.
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.
But they re much easier to install since no wiring is needed.
How many solar attic fans do i need.
Solar powered attic vent fans usually don t move as many cubic feet of air per minute cfm as hardwired fans.
That means you will need to double up your investment in this area.
Ok i would definitely not recommend an attic fan.
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.
However the utility of attic ventilation fans is actually quite a controversial topic.
Powered exhaust vents feature an electric or solar powered fan to create an effect similar to that of a turbine view example on amazon.
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.
Electric attic fans however often increase energy consumption and cancel out any savings unless the attic is not insulated at all.
The amount of solar attic fans a home needs will ultimately depend on many factors.
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.
To reduce that expense some homeowners buy an electric or solar attic ventilator.
You will probably need two solar attic fans to get the results you want.
The downside of attic ventilation fans.
This pressure balance improvement and the cooling provided by the air flow are most significant in the case of a leaky.
Good insulation reduces fan effectiveness.
If a cloud blocks the sunlight the fans slow or stop.
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.