Proper attic venting?


Old 08-18-20, 08:51 AM
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Proper attic venting?

I believe my one attic isnít vented properly. I was looking up replacement replacement attic fans cause mine is very very loud and noticed most attics are vented very differently.

this is my addition attic. About 600sqft
no vented soffit
no ridge vent

small gable opening on one side and a fan out the roof. Is this proper? Should the table intake be bigger or have a fan too?

my other attic has vented soffit and a ridge vent which seems to be the most popular way. It also has a gable vent too. Should that be closed up?
Old 08-18-20, 08:56 AM
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If you have a powered vent you need more open inlet air for air to enter the attic than the opening size for the fan. If your inlet area is too small the fan will draw a vacuum in the attic and can start drawing conditioned air up from the home. The amount of open area needed to let cool air into the attic will depend on the fan you choose. A bigger fan with more capacity will need more open area for the inlet.
Old 08-19-20, 06:50 PM
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Thank you for the replay. Hopefully you can help me a bit more. I got some more information today.

The actually square footage is closer to 500

i have one plastic gable vent that is 12x21

not sure how much cfm for the fan. Itís a master flow. 1/5hp 1050rpm 15Ē wide.

I also have vented soffit but the insulation covers it and doesnít have that foam piece to circulate the air up.

I would love to get rid of the fan when I put a new roof. Seems like thereís only negative things said about them.

im just trying to make my house more efficient. So Iím looking for help to make what I have now work better. Should I add another gable vent on the other side? Or suck it up and put the baffles in? Cause I think the fan is way over powered for the space

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