Return to the Renewable Energy Forum | Post a Follow-Up

 o
Attic / Roof ventilattion - hip roof , ridge vent , poser vent ?

Posted by rkpatt (My Page) on
Fri, Jun 3, 11 at 21:18

The house has a gable roof over the garage (gable vent on driveway end) tied into a hip roof over the main part of the house.

The roofer installed a ridge vent across both the gable and hip sections of the roof . He left the power vent (near the peak of middle of the hip roofed section ) the but told me to disable it which I did. However, the attic seems to be hotter than before. I am thinking that the area opening of the relatively short length of the ridge vent at the peak of the hip roof is too small to efficiently exhaust the hot air What are my options here ( run the power vent, add some more passive vents ("turtle back") high up on the hip roof fairly near the ridge etc ?

- Thanks


Follow-Up Postings:

 o
RE: Attic / Roof ventilattion - hip roof , ridge vent , poser ven

In theory, the attic temperatures are not an issue of concern. The roof ability to vent the moisture is what is the critical element.

Yes, zoned AC systems that are in the attic do have to work harder if that is the case, but speaking purely theoretically, the temp is not the issue if your envelope (air) and insulation layer of your attic floor are intact and sufficient.

You will always want to have more incoming air than you have exhaust air. If not, you run the risk of creating a negative pressure in the attic and thereby removing conditioned air from the conditioned zone below. This is what is often happening when people run attic fans and feel like they are "working" by keeping the attic cooler.

They are, but at the expense of sucking conditioned air into the attic.

I am guessing that you have soffit vents for the incoming air? Have you checked them and are they unblocked and open? If they are and you have good continuous make up air coming in, putting a couple of vents in the roof (not powered) is okay if you are concerned.

Again, it is not really a necessity if your attic insulation and envelope air tightness is good. If you are worried about a second HVAC system running in inhospitable environments, a little more exhaust to get the air moving shouldn't be too back. That being said, even a small ridge vent should flow plenty of air. Check your soffits.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Renewable Energy Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here