At a roofing supplier to day, they had a display and demonstration of a green energy Solar Attic Vent.
No power to hook up, they state no fire hazard.
They are using them more and more and more here. I am actually thinking about getting a couple for my roof.
Mechanical attic ventilation is a poor idea no matter how it is powered. Negative pressure in the attic is never good under any circumstances.
There is no negative pressure as the soffit vents provide the intake air and the fans, solar, turbine, or otherwise, allow for a flow of air in the attic.
I can tell you on our roof, when I installed the ridge vent, the temperature dropped at least 20 degrees in our attic.
Have you ever found attics that had insulation blocking any air intake from soffit vents. I do, regularly.
I also find vents on both sides of a ridge where the wind is pulling air out on one side and sucking in air through the other since wind, being less smart than the contractor, can only travel in one direction at a time.
Negative pressure in attics is not impossible.
I never said it wasn’t, but, it would take an extraordinary set of circumstances to occur…if the home were built properly.
If the home were built properly … it would not need a mechanical vent in the attic.
Agreed!
I’ve looked at getting one for a porch attic that was unvented (I have an old home). I ended up adding passive vents because the solar ones are extraordinarily expensive. I like them, though. They spin slowly and work great.
Built my home in 2004. It is now 104 degrees outside, and my A/C is not running. Attic is about the same temp. Reason?
I have a triple car garage with a side exit door that has a storm door. I keep that door open slightly when I am home. I also have a 30 inch square louver vent in the center of my 10 foot garage ceiling. I open it in the summer, and close it in the fall and winter. Along with proper one-side roof vents and plenty of eave vents, the heat just rushes out the attic.
During storms, however, I have to make sure the over-head doors and side doors are closed. One time during a storm the wind sucked several items off my work bench. Sometimes, too much of one thing is too much a good thing.
For the most part the solar powered attic fans (any attic fan) are snake oil.
JJ