The attic coffin you mention which is used to air seal and insulate pull down stairs scuttle hole or a whole house fan is good in theory but in practice is cumbersome to install.
Attic fan useless.
If the gaps in your ceiling are so big as to allow too much air through then fix the holes.
Even though a manufactured cover costs more it is far easier to install.
Get help with your home improvement projects.
Trying to solve the heat gain problem in your attic by using a fan is like lying out at the beach with a fan blowing over you and thinking you re not going to get a sunburn.
Attic fans suck air out of the attic to the outdoors.
Fans can cause increased loss of conditioned air.
You are spot on with your comment about thermostats.
But don t go crazy you need oxygen anyway.
Powerful fans that are exhausting air from your attic work best when they can get ample amounts of makeup or replacement air from outdoors.
Power vented attic fans are a true hazard vinyl is just gross no matter how you look at it fresh air intakes were a sad idea from conception.
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.
One static vent style is the turbine vent which uses wind to power its enclosed fan all it takes is a light breeze to rotate the blades and suck heat out of the attic view example on the home.
Mechanical attic ventilation fans may be powered in a variety of different ways.
The lack of soffit vents may cause the fans to draw air up from the inside of your home.
This radiant heat in turn heats up the rafters and everything else in the attic.
Most attic ventilators fitted to homes are powered off mains electricity.
Attic fans are typically used in warmer months when temperatures in an attic can exceed 120 f 49 c.
An attic fan does nothing to slow or stop radiant heat exchange.
As it turns out because the insulation slows heat from moving down into the living space homes with well insulated attics don t see a significant reduction in their cooling load when they add attic ventilation fans.
The only effective means are more insulation preferred or a radiant barrier up against the inside of the roof.
You need great soffit vents to supply the attic with all of the replacement air.
A fan may be installed in an attic for the different purpose of cooling a whole house venting hot air out via the attic.
Such fans are often called whole house fans.
Attic fans installed properly don t suck any more air out of your house than a normal bath fan.
If you stayed in a perfectly sealed house you would get sick and die.
It also requires no assembly.