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PolarBear44
12-04-04, 05:41 PM
I need some advice on ventilating an attic that has a hip roof with no overhang. The problem surfaced when a new central ac was installed. The ac will not cool the house below 79 degrees on a hot day. The hvac tech came back and checked his system and said it is working properly. he pointed out the roof type and said that was the problem. I had seven vents installed when the new roof was installed a few years ago.they are the small box type spead out near the peak of the roof away from the street. He said because there are no soffit vents, thus no air intake, that the vents near the peak are not efficient. The only place I can add intake is over the partially covered front porch. Would it be wise to install a power supply fan here to introduce the needed supply air. I could just put a screen in the porch ceiling, but I'm thinking that forced air would create some turbulance to help move air from all corners of the house. Any advice would be helpful

homebild
12-08-04, 04:36 PM
Without at least an equal amount of ventilation allowing air into the attic as you have vents trying to exhaust the attic, there is little in the way of new vents, powered turbined, or other that will help cool the attic.

Nevertheless, if you house it THAT warm that the AC won't cool the house, you likley have a greater problem with too little insulation than not enough ventilation.

Check your local codes to find out how many inches of attic insulation is required for your locale. Most regions today recommend at minimum 10-14 inches of attic insulation for proper energy conservation.

You can increase the passive ariflow to your hip roof by adding ridge vents to hips as well as ridges.

Ed Imeduc
12-19-04, 11:58 AM
Say lots of work. But if you can get to the fascia board there. There are small round aluminum vents. That you take and drill the hole for them and just tap them in the hole. Now in the attic you would have to put the foam rafter vents in over the insulation so the air would get into the attic over the insulation. Like said go for as 12" insulation up there.

ED ;)