Most “vented” attics aren’t vented at all, and temps get as high as 150 degrees
F. I don’t advise ridge vents. Attics with ridge vents still get really, really
hot. I read somewhere that convection currents in attics don’t start working
effectively until at least 125 degrees F. That’s hotter than I want my attic.
Frank James Graffagnino, a NASA engineer, installed ridge vent in 2004 at his
home in Friendswood. After studying the temperature sensing data, he found that
that the ridge vent took about 10 degrees off of the peak temperature in the
attic, dropping it from 141 to 130. You can see more at his website
So I don’t recommend ridge vent at all. Being that this is a renewable energy
group, the absolutely best solution is a solar powered attic vent. (Don’t
confuse this with the older AC powered attic vent. Night/day difference.) A
high quality solar powered DC attic fan is about 2x the price of ridge vent, but
will really ventilate the attic. Several people have told me that it will drop
the attic temperature to about 5 degrees above outdoor temperature. That really
cools it down. I installed a solar powered attic fan 1 year ago. My kwh usage is
down 6.3% from last year. An additional benefit is that the increased
ventilation can keep humidity from building up in the attic.
Several manufacturers offer quality solar powered fans with long guarantees. You
might check out www.atticbreeze.net or http://breezemaster.net/ Travis Hipp,
the engineer behind Attic Breeze, answers the question of how much ventilation
is needed at http://www.atticbreeze.net/Ventilation%20Requirements.htm Your
roofer should be able to install the fan. No electrical hookup is needed.
Another poster was absolutely correct in that intake air is vital. Air will
follow the path of least resistance. If you don’t have enough soffit intake, a
powered attic fan can pull conditioned air from your house right into the attic.
Not a good idea. The way to check if you have enough intake is, while the attic
ventilator fan is running, to use an incense stick around attic doors or scuttle
holes. If the smoke is being pulled into the attic, you don’t have enough soffit