Using attic heat for the house

[TheyCallMeDave]

Im curious to know when your attic is at 90 f, what the outside temp. is at the time and if it was a totally sunny day ? Im in northern Florida and ive never measured my attic temp. but i strongly suspect that it is at least 90 f up there when its 60 f. out due to the intense suns rays beating on my black asphalt shingles. This winter ill pay closer attention to that and just may implement something like you have to take advantage of the accumulated heat up there for the living room area where i spend nearly all my waking hours. During the summer months, i wouldnt be surprised if my attic is at 130 f. at 6 pm which has me thinking I should throw a 300' coil of 3/4" Pex up there for shower water (cooling down with some cold water of course) .

[Daox]

The ambient temperature varied quite a bit. The attic temp was much more stable. I'd say the ambient temperature was anywhere from 40 to 60F.

[TheyCallMeDave]

Originally Posted by Daox

The ambient temperature varied quite a bit. The attic temp was much more stable. I'd say the ambient temperature was anywhere from 40 to 60F.

Too bad there isnt a way to get your attic heated up better for your winter months (?)

[Daox]

Me and GaryGary shared emails about this. We think that if you could find a way to cutoff the attic vents to warm things up this would be possible. However, you still have to deal with the humidity in the air and that may cause issues. So, you'd need some sort of automated vent system and it would likely be complex and costly.

[TheyCallMeDave]

Originally Posted by Daox

Me and GaryGary shared emails about this. We think that if you could find a way to cutoff the attic vents to warm things up this would be possible. However, you still have to deal with the humidity in the air and that may cause issues. So, you'd need some sort of automated vent system and it would likely be complex and costly.

If your attic vent openings were no larger than about 12x12", then you could put on some regular air registers with a manual adjustable damper as integral , that you could open and close using something long from the ground . But, i doubt it would help that much. The solution would be to cut out a large section of roof and fit a Solar Collector over the opening on the southside of the roof keeping it covered up in the summer months....but now we are getting a little outrageous for most people. lol...

[GaryGary]

Originally Posted by TheyCallMeDave

If your attic vent openings were no larger than about 12x12", then you could put on some regular air registers with a manual adjustable damper as integral , that you could open and close using something long from the ground . But, i doubt it would help that much. The solution would be to cut out a large section of roof and fit a Solar Collector over the opening on the southside of the roof keeping it covered up in the summer months....but now we are getting a little outrageous for most people. lol...

Hi,
Don't know if you caught this system by Randy:
An Invisible Solar Attic Space Heating Collector

He has basically built a collector using the roof surface as the absorber, and the truss rafter bays and the air channels for the collector.
He has a supply plenum along the bottom and an return plenum along the top -- air from his living room is circulated into the supply plenum, up the collector, and back out the return plenum to his living room.

The performance is still not going to be as good as a glazed collector, but it looks like it might do pretty well in some climates. One could also glaze over the top of the shingles with something like SunTuf polycarbonate glazing. Shingle life might be an issue, but when they wear out you could replace them with a "real" metal roof

There were some comments on fire safety, but I think these could be addressed as suggested.

It would be a really nice way to integrate a collector into a metal roof.

Also, this one is pretty interesting:
IWillTry.org » Build a Solar Attic

I really think that working out a good way to integrate solar collection with attic construction could pay some huge dividends -- it could potentially add almost nothing to the cost of a house, but supply significant heat?

Gary

[TheyCallMeDave]

Originally Posted by GaryGary

Hi,
Don't know if you caught this system by Randy:
An Invisible Solar Attic Space Heating Collector

He has basically built a collector using the roof surface as the absorber, and the truss rafter bays and the air channels for the collector.
He has a supply plenum along the bottom and an return plenum along the top -- air from his living room is circulated into the supply plenum, up the collector, and back out the return plenum to his living room.

The performance is still not going to be as good as a glazed collector, but it looks like it might do pretty well in some climates. One could also glaze over the top of the shingles with something like SunTuf polycarbonate glazing. Shingle life might be an issue, but when they wear out you could replace them with a "real" metal roof

There were some comments on fire safety, but I think these could be addressed as suggested.

It would be a really nice way to integrate a collector into a metal roof.

Also, this one is pretty interesting:
IWillTry.org » Build a Solar Attic

I really think that working out a good way to integrate solar collection with attic construction could pay some huge dividends -- it could potentially add almost nothing to the cost of a house, but supply significant heat?

Gary

Wow...his plenum idea in the attic is very cool. Looks like its pretty effective for him too.

I think new homes could definetly be built to take advantage of attic heat for space heating at a minimal cost , and be a real selling point for the consumer.

Upon careful consideration, ive decided to not do the attic Pex tubing Collector which would be the cheapest way out , and instead, build and install a Collector box on ground level and thermosyphon the water to my existing 40 gal. water heater ... and hopefully never have to turn on the water heater . I figure a grand total material cost of $350 and be gauranteed some good quality hot water all the time. Its certainly more advantegeous if you live in sunny hot Florida as i do !

[Daox]

Originally Posted by Daox

Well, I had a bit of a hiccup with the system over the weekend. I actually wasn't even home, but came home Sunday night and the blower was blowing. However, I also saw that the damper in the kitchen wasn't pusheed up as high as it normally is. So, I went to check things out and sure enough, one of the fans wasn't turning. I'll have to pull it out and see whats going on.

I climbed up into the attic last night and found out what the problem was. The armature of the motor was rubbing on the stator. I simply loosed up the bolts on the end and re-adjusted it. It didn't even look like it moved, but it was working fine after the adjustment.

Thus marks the first day of using the attic heat fan. I could have been using it a few day and or even a week earlier (~September 1). Its been in the 40s at night and up to the low 70s during the day. So, the house is having a bit of a hard time staying warm. It'll be interesting to see how long it'll be usable.

[Piwoslaw]

Woohoo! Solar heating season is on

[Daox]

I'm not quite so excited! I really want to have the hot water panels up this year befor winter, and its really looking iffy as time passes.