attic venting question


  #1  
Old 02-19-04, 11:00 AM
skratka
Visiting Guest
Posts: n/a
attic venting question

I have just moved into a ranch and want to vent the attic. The roof is old but is holding up well.

The attic has a few "boxes" poking through the top of the roof near the sides of the top ridge for passive venting but I want to put in an electric attic fan.

Do I have to cut open the roof or can I just install a fan to vent out through one of the existing openings?

Thanks
Steve
 
  #2  
Old 02-19-04, 01:46 PM
Ed Imeduc's Avatar
Member
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 17,505
Upvotes: 0
Received 1 Upvote on 1 Post
If you look you can get a attic fan with the tstat on it that would go on the roof just like the button vents you have now. Dont forget you also want vents in the overhang around the home also. ED
 
  #3  
Old 02-20-04, 07:52 AM
skratka
Visiting Guest
Posts: n/a
Thanks for the quick repsonse.
I have been reading all the usefull threads on this site and trying to put together all the information.

Are you saying that I may be able to mount a fan and have it vent out the existing vent? I would prefer not to have to start with tar, shingles and flashing but am worried about clearance and would cut a new hole if the lower clearance would have the fan only blow 75% of air outside and 25% back into the attic.

The house has 2-3 foot soffits around the whole house covered w/ aluminum siding. I do not see any visible soffit vents from the outside. Is is possible that there are no vents other than the two caps at the peak?
I will check from the inside but don't know what or where to look.

If there really is no venting for intake puposes, would it be diffucult to install vents in the soffit. (Are these called undereave vents?) How many vents would I need. My attic is about 2,000 sq foot. The highest point is about 6-7 feet tall and slopes down to the soffit.

Thanks again for your help
Steve
 
  #4  
Old 02-20-04, 01:51 PM
Ed Imeduc's Avatar
Member
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 17,505
Upvotes: 0
Received 1 Upvote on 1 Post
old school 1sq ft for 150sq in the attic new school 1sq ft for 300sq ft in attic Cfm for attic sq ft X 0.7=cfm

So 2000sq = about 13sq ft
1/2 in = 6 1/2sq ft and 1/2 out =6 1/2 sq ft of vents

Id say take one of the button vents you have and cut out what you need and replace it with the power vent fan on the roof

ED
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: