That's a big attic--is that the floor area, or the roof area (both faces)?
I have an attic of about that floor area, w/ a crappy mushroom fan. I
insulated between the joists w/ fiberglass, covered by 1/8" paneling, which
made all the difference in the world.
And, essentially no other venting. The teeny ones that were there were
covered, and instead I crack the attic door/ladder to vent the warm air
rising to the top floor from the house.
The fan is on a thermostat.
A small A/C, about 6,000 btu, makes the space entirely inhabitable in the
summer, ditto a small dehumidifier in the winter.
In the winter, I put a piece of paneling over the fan opening.
I personally don't understand the hyper-venting of attics. At least not in
the context of good insulation.
Mr. P.V.\'d (formerly Droll Troll), Yonkers, NY
Click to see the full signature.