When I replaced my roof 2 years ago, they installed a ridge vent but kept my two 12x20 gable vents (passive), along with 10 circular soffit vents (2" diameter) with foam baffles in between all rafters.
During those two years, I noticed larger than usual ice dams after snow storms and wondered why.
Prior to the new roof, I had installed two layers of insulation (perpendicular) with little to no ice dams.
After reading some posts here and researching the topic, I was prepared to install larger, square soffit vents and close up my two gable vents.
But then, I read the article from airvent.com (http://www.airvent.com/pdf/literature/PAVbooklet.pdf
, page 11) which talked about how "a roll vent with an internal baffle does not pull air from the attic" whereas their product which has "an externally baffled vent pulls air from the attic from both sides of the ridge vent".
I have a ridge vent with internal baffles.
Can some pros weigh in as to the legitimacy of this information and what I should do to improve my air flow?
I plan on replacing those small soffit vents either way.
Have you used those "externally baffled" ridged vents? What did your customers say? Would it be fairly easy for a DIYer to remove the existing one and replace it with this one?
Or should I install some gable fans and keep the existing setup?