ReadyToRetire
Basic Member
Posts:212
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| 15 Oct 2008 02:17 PM |
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For the next 4 years, I'm still in my 25 year old house; it's burned through 4 of the 12" attic fans with sleeve bearings. I've looked but cannot find an attic fan with ball-bearings.
Is anyone aware of one?
Thanks for any suggestions you can offer.
Larry
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GWhittleAL
New Member
Posts:26
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cmkavala
Veteran Member
Posts:4327
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| 18 Oct 2008 03:59 PM |
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Larry;
a lot of the research I have seen shows that while an exhaust fan will lower attic temperatures, they do more harm than good , as they cause negative pressure within the conditioned space too.
I love the "savengr" web site picture showing a "properly" installed unit ....... with duct tape and cardboard? |
 Attachment: faninstalled.jpg
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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PanelCrafters
Advanced Member
Posts:680
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| 18 Oct 2008 07:09 PM |
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Posted By cmkavala on 10/18/2008 3:59 PM
Larry;
a lot of the research I have seen shows that while an exhaust fan will lower attic temperatures, they do more harm than good , as they cause negative pressure within the conditioned space too. That may well be true. However, in a Hot Humid climate, I have used them with success. Even with a decent amount of insulation, you could tell the difference(in temperature within the living area) when the fan was not on.
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| ....jc<br>If you're not building with OSB SIPS(or ICF's), why are you building? |
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cmkavala
Veteran Member
Posts:4327
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| 18 Oct 2008 08:34 PM |
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Posted By PanelCrafters on 10/18/2008 7:09 PM
That may well be true. However, in a Hot Humid climate, I have used them with success. Even with a decent amount of insulation, you could tell the difference(in temperature within the living area) when the fan was not on.
Seems to be the exact opposite of what the Building Science Corp. thinking is for Hot-Humid climates? You would be actually be creating greater negative pressure, sucking out conditioned air ,while inducting more humid air into the attic space and conditioned space. |
Attachment: Scan10010.jpg
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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ReadyToRetire
Basic Member
Posts:212
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| 18 Oct 2008 09:03 PM |
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GWhittleAL,
Chris comments on what the vendor considers a "correctly installed" unit; and, if you look at the vendor supplied hood box, it does not look well made -- the corners aren't broken cleanly and the flanges aren't flat. And the description includes the statement: "This fan features an external rotor to which the fan blades are
welded. This unique design reduces blade flex and vibration and
eliminates one of the shaft bearings." It's not clear what bearing they eliminated.
I DO appreciate your posting the cite. I'd spent a lot of time
searching the web, and that had been the only ball-bearing fan that I
found. Although the vendor is only importing the fan, not making it -- given those issues and the price -- I was hoping that something else might pop up.
Very respectfully,
Larry
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ReadyToRetire
Basic Member
Posts:212
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| 18 Oct 2008 09:14 PM |
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PanelCrafters, Chris,
My house is 25 years old and built before BSC's argument on what should be done: It has a vented attic. The house has a hip roof to which we added a ridge vent, that cooled the attic and, as a result, the house temp also dropped several degrees. But the vent is not long enough to be sufficient; I can feel the difference when the vent fan is not working. I don't want to spend the money to seal and insulate the attic because I only plan on being here another 4 years, and I don't anticipate that many buyers would perceive value in the upgrade. So. . . I want to restore the failed vent fan as an inexpensive way to make the house more comfortable while maintaining it's original design.
Very respectfully,
Larry
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cmkavala
Veteran Member
Posts:4327
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| 19 Oct 2008 10:57 AM |
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Larry;
I don't doubt you can feel the difference, my point was that if a side by side comparison was done the power vented house vs. a naturally vented house, the powered would consume more energy, with the additional negative pressure being counter productive to the HVAC system
In your case its probably not the cost, its the comfort
For NEW construction the BSC recommends unvented roofs for Hot-Humid climates. |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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PanelCrafters
Advanced Member
Posts:680
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| 19 Oct 2008 04:00 PM |
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Posted By cmkavala on 10/19/2008 10:57 AM
Larry;
I don't doubt you can feel the difference, my point was that if a side by side comparison was done the power vented house vs. a naturally vented house, the powered would consume more energy, with the additional negative pressure being counter productive to the HVAC system
In your case its probably not the cost, its the comfort They do make Solar Powered vents. And, 'Negative Pressure' need not apply to a well sealed attic. For NEW construction the BSC recommends unvented roofs for Hot-Humid climates. Actually, they recommend both.
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| ....jc<br>If you're not building with OSB SIPS(or ICF's), why are you building? |
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cmkavala
Veteran Member
Posts:4327
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| 20 Oct 2008 09:32 AM |
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jc;
thanks for reinforcing the point |
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| Chris Kavala<br>[email protected]<br>1-877-321-SIPS<br /> |
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