solar powered attic fan? any experience?

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Icarus

 

The radiant barrier is a good choice, but the paint is crap. I installed the bubble wrap type radiant barrier in my attic...big difference. it took me a while to install the barrier. Now they make a OSB with the radiant barrier right on there, too bad i did not know this back when I decided to re-roof.

 

I have a solar attic fan, I've got a Attic Breeze fan that works fantastic, defiantly makes a difference, I sleep on the second floor, I've got the closest room to the fan and I never here it. The government is doing all kinds of tax credits right now, I got most of the info off of solar-attic-fan-info . com, its just a good resource to start with you know?

 

Solar attic fans are great. I would go with a 25 or 30 watt version. Look at SolarAtticFanSource.com. Once you get them installed there is no more cost to them.

 

I am thinking of getting the solar powered flood lights(LED) and solar powered area light for my Feed shed. I saw them at Sam's club, but skeptical about their longevity as a few things I got from Sam's didn't last very long.

 

We put a SunRise 1250 solar-powered attic fan (without thermostat) through our roof in July 2008. We found it lowered the peak summertime attic temperatures by approximately 30 degrees. For us in New England it also been beneficial in the winter by eliminating condensation.

 

Just a thought -- I assume you have a frame built house, as opposed to our (typically concrete and flat) roofs here on Guam. Still, I dropped insolation considerably simply by cleaning my roof and painting it white. It's a full 10 degrees Fahrenheit cooler when I get home at night than it was prior. I suspect a similar reduction in thermal gain could be accomplished by going with a white (silica?) shingle next time you do your roof.

This doesn't change the fact that, yes, venting heated air out of your attic with solar operated fans is a fine idea, it's just an added thought.

 

Using $750 utility (and even more Federal rebates to come), we decided to have our entire attic and crawslpace foam insulated. Came to about $1200 installed. Much, MUCH better value winter and summer (plus it won't break in a few years, no holes in roof, and quieter). Attic temp is now within 10 degrees of rest of house (used to be 150 in the summer).

 

Interesting. Are we talking some kind of a blow-in foam? I've often speculated on the possibility of putting something like that on our roofs, then sealing it . . .

 

Not that this will help with the fan issue, but why is it that houses in vastly different climates look pretty much the same? Do you think we'll ever catch on to the idea of constructing buildings to minimise energy use?

 

I have an attic fan and I have solar panels. From an attic fan point of view, it's terrific. It's 110 watts and before when it got hot, the upstairs would be easily 3-4 degrees warmer than the downstairs. Now with the fan, the upstairs is the same as downstairs.

 

Are you confusing an attic fan with a whole house fan here? The attic fan cools the attic only and the giant whole house draws air out of the upstairs rooms. In either case, you need s crap load of "ventiliation to allow fesh air into the attic". Even with a full length ridge vent you need a lot soffit vents, that most houses do not have--another very sizeable expense. Also, you should be aware that the average life time of these noisy, motorised, energy consuming devices is only about 5 years, then you have to buy a new one and have it installed. Keep it simple: save a lot of energy and effort and noise by simply foam insulating your attic while the rebates are here.

 

Our attic fan is 35 years old. It looks like we might be slightly over the estimated 5 year life span.

Tom

 

solar attic fan? Yea, we got that.
But why stop there. Our electric boat is solar ... and our TV's ... stove ... microwaves, refrigerators, dishwasher, garbage disposal, amateur radios, lights, PC's, printers, space heaters, phone chargers, phones, fax, sterio, garage tools, block heater, battery backup power supply ... did I miss anything?



All that to say ... why stop at just an attic fan. Yes, it's a start, but MANY of the "solo" systems utilize moderate quality solar cels. malibu lights are THE worst quality cels known to man. If you possibly can ... get the real McCoy's ... and they'll last a lot longer ... they'll be way more efficient, and run a WHOLE lot more things, than just one device. There are some great deals out there right now on PV systems.

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Gotta wonder how much energy is being used/wasted by a 35 year old motor.

 

It's a garden variety induction motor, so it's pretty easy to guess the efficiency. I'm more worried about it catching on fire when the bearings seize up some day. I really should replace that beast.

Tom

 

There's actually a huge range of efficiencies in electric fans. Just look at bathroom fans. Very few are Energy Star rated - but those that are draw a fraction of the power of non Energy Star rated fans. (Seriously - like 20W vs 100-200W for the same volume of air). Panasonic makes some great ones that are basically inaudible and very efficient - I need to get some of those in my house but unfortunately they aren't as "pretty" as the ones I have now.

Anyway - something hill missed is that PV on the roof also reduces attic temps a great deal - it's like having your roof in the shade all the time!

 

Solar roofs are certainly the solution to our national electrical grid problem and I'd like to have one too, but the whole house/90% of all electrical usage systems cost a whopping $30,000. 15-20 years is too long a payback period. I'm anxiously waiting for the prices to come WAAAAAY down when the payback is less than 5 years.

 

It's definitely a attic fan, not a whole house fan. The install was about $250. A whole house fan install is going to be over a grand and you'd need to cut some vents in the ceiling.