Attic Ventilation

[stouto]

I am getting ready to reroof my home. I have researched attic ventilation on the internet and I am totally confused about ventilation requirements.

My home is a single story ranch with 2076 sq. feet of heated area and a two-car garage (529 sq. ft). It has 14-soffit vents (7X14 inches each), four gable vents (18X22 inches each), and three roof power vents.

My contractor suggested that I cover the power vent openings in the roof and install a ridge vent. Would this be a better method for attic ventilation than the power vents? Also, would the gable vents have an adverse effect on the ridge vent cooling?

Any suggestions would be greatly appreciated. Thank you.

[dennism]

The confusion problably stems from some giving a simple, one size fits all solution, to a fairly complicated subject.

Try these links for a little more info and see if that helps with your decision.

Can I use a powered attic vent with a ridge and soffit vent.?

Roof Ventilation Short Circuit

Roof Ventilation

[stouto]

Thanks Dennism. Good info. It looks like any combination of vent systems should work ok on my home. Do you know the source of the info?
Jess from Georgia.

[roofing101]

Hello, If your power vents are working ; DONT REMOVE THEM!!!! they work much better than any ridge vent will ever work. 3 power vents in a roof is alot are you sure they are power? or "can's" which are alum , square, about 12"x12" ? If they are power then you might need some more soffit vent for intake; it sould be 50/50; but you can never over vent the soffit, but under venting is bad beacuse it slows the cooling and makes the fans work harder. hope this helps! if you go with a ridge vent use shinlge vent2 from airvent it works the best. airvent.com

[Ed Imeduc]

The good books say 1 sq ft for every 150 sq ft of attic of attic 1/2 in at the over hang and 1/2 out at the ridge.
For the power fan attic sq ftX0.7= the cfm of the fan. I too say forget the ridge vent. Rain can blow in and snow can block them. Turbine ones are bad also FL has outlawed them

[roofing101]

Originally Posted by roofing101

Hello, If your power vents are working ; DONT REMOVE THEM!!!! they work much better than any ridge vent will ever work. 3 power vents in a roof is alot are you sure they are power? or "can's" which are alum , square, about 12"x12" ? If they are power then you might need some more soffit vent for intake; it sould be 50/50; but you can never over vent the soffit, but under venting is bad beacuse it slows the cooling and makes the fans work harder. hope this helps! if you go with a ridge vent use shinlge vent2 from airvent it works the best. airvent.com

Also I forgot the Gable vents should be coverd no matter which vent you go with. the vent power or ridge needs to pull air from the eve's, but wont if you have the gable vents open... thanks