Roof Vents That Can Be Closed

[W]

Does any vendor make roof vents whose vent openings can be shut from inside an attic?

Our residential roof is a 6/12 sloped roof with composite tiles. We have four exit vents on the sloping roof, which have rectangular cut outs in the roof about 15" x 6" dimension. There is a sheet metal cover on these and they slop down to guard against rain, with vent opening on the down side.

Recently we installed an attic ventilation fan on top of the roof that replaces one of these vents. The problem is this fan is pushing air out the attic, but air is rushing back in through the other three exit vents. The air coming through those vents is hot air from the roof, so it just cycles hot air in and out of the attic.

We could just tape off the three remaining vents, but I would really prefer to find a replacement vent whose louvered opening could be dialed to different levels of open. Does such a product exist?

[PeterD]

There may be multiple problems. Consider that your 'intake' air must come from somewhere and that location (vent) may be too small, forcing the roof vents to supply air.

If this were my project, I'd see if I could make the roof vents 'one way' that is make a flap that closed when they were not venting outwards. I'm sure something could be tossed together without too much trouble.

[W]

We already sized the intake vents around the perimeter of the roof and we have about 150% coverage to the actual requirement.

You are right that is a much better design. Do you have any ideas on where to buy it? Can we buy from you?

[PeterD]

Uh, no I don't sell this kind of stuff... (sorry).

Generally I'd guess you may have to fabricate what you need, I've no idea what the roof vents are really like (underneath, for example) but I can imagine it should not be terribly difficult to come up with something that will work.