Unless your roofing system has insulation on the roofing deck and is designed without ventilation your furnace should not be heating your attic.
The attic door is very hot.
During the hot months many people leave their garage doors open in the day or there is even a screen door type covering for a garage.
A thick insulation between 14 to 18 inches will help reduce heat from entering your home.
Heat moves from hot places to cooler places.
The garage ceiling has a door to the attic.
Attic fans push out the hot air and pull in the cool air from the vents installed on your roof.
High temperatures inside your attic shorten the life span of shingles.
When it s hot outdoors it s hotter in your attic.
If not you may want to consider adding blown in insulation.
Set the garage door so it closes leaving about 1 foot gap at bottom also lets cats come and go as they wish.
Hopefully the ceiling cavity between the garage and the finished spaces was insulted.
To ensure that the attic fan is working properly you need to make sure that your attic is sealed up tight where it touches the ceiling of the top floor.
A hot attic is bad for several reasons.
Imagine how hot your house would be if it was 120 degrees outside.
Not the overabundance but the lack of insulation in the attic.
Be sure that the access door is well fitted and doesn t let air escape around the edges.
They can easily be 120f.
Central heating ac systems and ductwork are often in the attic.
And it can cause your air conditioner to work harder than it needs to and send your energy bills soaring with the temperature.
Lacking these i did the following.
An overheated attic can bake asphalt shingles on the roof and cause them to deteriorate.
Attics are very hot during the summer and cold in winter.
You would think that an attic fan sometimes called a powered attic ventilator or pav would keep the attic space cooler by exhausting hot air.
Excessive heat deteriorates items.
Another reason your attic is so hot is because of insulation.
The heat from the garage will absolutely contribute to high temperatures in the attic space above as well as the finished rooms.
The attic is a huge determinant in keeping your entire home cool so the first place to start cooling your home should be the attic.
An unventilated attic can reach 150 degrees in the heat of summer 50 degrees higher than it should be.
A pav does indeed blow hot air out of the attic but unfortunately it also sucks cool air from your living space into the attic through leaks in walls and ceilings.