We had a new roof put on this June. The old roof was cedar shake and it was removed. The new roof is "asphalt" composition shingle. Plywood was installed on the roof. Six turbines were installed on the roof with only 8 functioning vents (12 were installed, but 4 are in a "dead-end" vaulted ceiling roof. In addition, the vaulted ceiling area has a new ridge vent with very little free air below and no real connection to free attic space.
Our gas heating usage has gone up by 50% as measured by MCF even after controlling for temp/heating degree days. The gas company agrees that we have a problem. They inspected for leaks - found none. Are 8 to 12 small soffit vents sufficient for 6 turbines? Can these turbines draws so much as to pull hot air out of the heated part of the house? What would be the recommended number of 6 by 10 soffit vents for 6 12inch-diameter turbines? Do you have other recommendations?
Thanks so much, our pocket books ache for the higher usage/higher price gas.
I have asked the roofing contractor to recalculate the number of vents - there has been no reply as yet. I suspect they want to believe the 4 non-functioning vents work - but it appears to me that even 12 good vents are way too few. Thanks again.
You need to have more intake than exhaust. The minimum is to have an equal amount. Did your roofer pull a permit? Probably not. Your building dept will send an inspector to determine if the roofer did a job to code. Each city has different requirements. I am the installation manager of WeatherGard and would be more than happy to assist you. Email me at email@example.com