I was thinking of installing some sort of roof vent directly over my unfinished attic to vent out some of the heat and moisture in summer. I live in NY. My house was originally a ranch and then the original owner had a second story put on the house (40 years ago). From what I can tell by living here for the past 15 years the upstairs level was not constructed very well with regards to energy efficiency and/or insulation. There does not seem to be any soffit vents, other than the few small ones I added myself in the past few years. The attic, which I can walk into as the previous owner put plywood down, has a small double-hung window at one end which I always leave open for ventilation. Above this window is the small typical louvered aluminum vent.
Two years ago I had a new roof (asphalt shingles) put on. There was a fair amount of water damage to the underlying exterior plywood which the roofers replaced as they went along. I have no doubt that part of the damage was caused by poor/no ventilation.
I should also note that the previous owner, for some reason although the attic is not finished, placed foil-faced insulation under all the roofing in the attic. Not sure why he did this and I also think that this is not a good idea in winter as it probably traps moisture right at the roof wood. I have seen some frosty areas on the attic roof wood on occasion.
In summer the upstairs living areas get really hot. I do have central a/c up there but it cannot keep pace with the afternoon heat of the sun and does not cool the upstairs until after the sun goes down. This leads me to believe that there is little, if any, remaining insulation under the roof but above the living areas.
I was originally thinking of installing a powered roof vent but I hear that sometimes the pressure from the vented air can suck air conditioned air from surrounding rooms and out the roof. So now I'm not sure about doing this. Perhaps installing some non-powered roof vents or a turbine would help but without soffit vents to allow air in under the eaves it would probably not help much.
I want to get a qualified energy audit person/company in to my house for additional ideas. Any thoughts on all this?
Thanks, Walter