roof/attic fans

[Steve S.]

Greetings all-
Maybe this post should be under heating/cooling section, but just wondering what the consensus is on attic ventilation. The system in my 1985 Champion consists of soffit venting around the perimeter of the roof (shingled-low pitch) and a series of vent stacks on top of the roof (2 at each end/side) and a central vent with an electric fan. The electric fan stopped working several years ago and I finally got up there recently and pulled out the vent to expose the burned out fan motor (lucky it didn't start a fire). Was thinking of installing a solar-powered fan or simply removing the fan and all electric wiring and just keeping the stack as a passive vent. Is the powered fan really that important in keeping the attic space cool and dry? My roof seems to have fared very well without the fan working all these years (25 years old and still looks very good). I welcome all ideas/experiences.
BTW, I finished my vinyl skirting project about a month ago. The Parkside skirting really looks nice and very easy to put up except for all the hole-drilling in concrete. It's nice to go down under and see light all around since the Parkside panels all have vent holes in them...no need to add vents or doors. The whole project cost me about $600.

[JD]

Hi Steve,

Great post about the skirting by the way. Lot's of people would find that information useful.

Seems to me that your roof has done quite well. As for passive venting, your home seems to be vented as well as the homes being built today. My own experience with an attic fan is, I would use them in the evening when it cooled off outside, to replace the hot sunbaked air in the attic with fresh cooler air to help the rest of the home cool off. But we live in quite different climates. Here in Fresno, CA, we will have a month of 90 degree weather (being June) followed by a month or two of 90's and 100's. Extreme highs can get to 115. Then a month of so of 90's followed by a couple of months of very pleasant weather. So we get 3 to 4 months of heat. Nice thing about our area is we almost always cool off real nice in the evenings, usually to the mid to high 70s. Blowing that hot air out of the attic really helps here.

JD

[Harry]

Hi

I wish I had an attic fan. I think I'll add it to my do-list.

I am a fan of Parkside vinyl skirting. See my photos.

Harry

[Steve S.]

Thanks JD and Harry for your comments...much appreciated.
JD you're right that we live in two very different climates. Heat in the attic is not so important here in northern NE as is moisture build-up which can create mold problems and rot rafters and sheathing from below. But I'm glad my roof has held up well...the builders of this home spared no expense on the roof. I think I'll just leave the vent fan-less for now. Solar roof fans are a bit pricey.
Harry, I like how you put the Parkside skirting around your deck as well as the house. I was thinking of doing the same but my deck is over 48" high, and too high for skirting (as per manufacturers instructions).
Cheers, Steve

[Guest]

Hello all I was also thinking about PAF (Powered Attic fans) to help keep cooling cost down, but after I google this found out it may not be worth it.
I don't think installing sprinklers on mobile home roof is a good idea also, but seems to work better though I don't think the park manager would approve.

http://www.clarkpublicutilities.com/Res ... 5/05_06_05

[troyster]

Steve, what about using a whirlybird fan? it would cool your roof using only the wind.

[JD]

Hi Jim,

Great article! So many times logic tells you one thing when science can show something totally different. There are several points that relate to mobile homes that this article brings out.

Less than 12" of insulation? The newer homes will have R30+ insulation, but the older mobile homes won't have room for a true R-11. That is what I find in older homes, but near the eave of the roof, the space can squash down to 2-1/2". The old insulation has also flattened out a lot taking more of insulating qualities away.

The part about radiant heat heating the living space during the day is good information. Helps us to re-think powered ceiling fans. But many mobile homes will remain hot inside even as the sun is setting or set. That may be a good time to run an attic fan to help disperse the built up heat allow the evening cooling to begin.

Thanks for the article. I am going to print it up and use it with my handouts when showing my insulated roof product. Installing roof insulation above the existing roof really does help here in the Central Valley, California.

I agree about sprinklers on the roof. Probably wouldn't go over real big here. Very hot and dry agriculture area where water is precious.

JD

[Harry]

Hi

Also I was hoping that an attic fan would help with an inherent moisture problem built into this home.

Harry

[Mark]

Most mobile homes built in the last 10 years have a built-in attic fan. With most systems, the fan does two things -- it vents the attic, and it brings in fresh air to the furnace. For Coleman, this would be called a 'Blend Air System.' For Nordyne, it would be called a 'VentilAire' system.

Mark

[Guest]

Thanks JD, hopefully it will bring in more business for you.