Hello experts,
What’s the real story behind ventilating an attic? I’ve heard baffled ridge vents are the way to go when properly balanced with soffit vents because it’s total roof venting at the hottest part of the roof. But I’ve also heard a temperature and humidity controlled electronic fan is better because there is less chance of leaking. What’s the real truth? The ShingleVent II seems to get all the press as the way to go in ridge vents, is that really true or just good marketing?
Darge
Replies
You're looking for experts and truth? You may have taken the wrong exit off the electronic superhighway!
What's the slope of your roof? What's the roofing material? What climate are you in? How's your insulation. Have you sealed all air leaks into the attic?
Properly installed ridge vents seem to have very few leak problems. Power ventilators may have their place, but I prefer to let nature do the work whenever possible.
Al Mollitor,Sharon MA
MOJO,
"What's the slope of your roof? What's the roofing material? What climate are you in? How's your insulation. Have you sealed all air leaks into the attic?"
All good, AND NECESSARY questions, and a point that I passed on to one of the folks at Taunton that detailed info is important, and mentioning this (being detailed vs. vague)should possibly be in the welcome page.
Jon
I'm operating from memory but in the late 70s the Department of Energy financed a study and made a few interesting discoveries. Some became common knowledge. Like the effectiveness of the soffet and ridge vent combination. This was deemed to be the vent system with the best cost/ benefit ratio.
Other conclusions were reached like turbine vents were no better than a simple hole or trough of an equal open area. Power vents were determined to be less cost effective than the soffet and ridge vent configuration assuming sufficient insulation on the ceiling.
Other points seem to have either eluded builders or been swamped by other factors, like street appeal and salability. Simple fact being that a stark white roof will save money on AC. The same roof tends to visually advance and to make the body of the house look smaller. Conversely a dark roof can keep you AC struggling but it recedes visually and so makes the body of the house seem much larger.
Given the same cost people tend to buy the house that appears larger. No matter that the plans show them to be identical in terms of floor space. The increased energy costs only become apparent after the check has cleared.
Baffeled ridge vents are no more likely to leak than a fan unit, do a better job, and require no maintenance. Fan units tend to fail after 5 years or so.
We've had Shingle Vent for the past ten years and never had any leaks due to it. When you go up into the attic you can see (from the spots on the insulation) that a little "spitting" blew through from time to time, but no more than we got with the old mushroom vents.
I just found this fantastic article over on Roofing Contractor.com it covers most aspects of the ridge vent.
Adam