Solar furnace

Anything off grid. Energy, waste management, water supply, housing, whatever.
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paxman9270
Posts: 5
Joined: Mon Feb 09, 2015 10:56 pm

Solar furnace

Post by paxman9270 » Tue Feb 10, 2015 12:51 pm

Troy, ElectroPig Von Fokkengruuven made a great point about solar furnaces on one of your recent videos, and I haven't had the time to explore your forum, as it's quite extensive, and I'm new here, but you know me from my YT comments. I know you said you have a difficult time reading comments over 48 hours old, so I wanted to make sure you saw my reply to him about it.
+ElectroPig Von Fokkengruuven I've seen those videos, and they are informative, and worth a looksee. 100+ cans hot glued together in an acrylic box with holes in the tops and bottoms. Spray painted flat black, and tilted toward the sun. Small 12V fan sucking/blowing the warm air into a house vent. That could've been a huge help during the days when Troy was in the camper or RV. It could still be an interesting side project with the tiny house on wheels this spring/autumn on the roof. Best of all, the building materials are pretty cheap, and Troy sure has the knowhow to do it. He could even make a tiny solar powered one for the chicken tractor on wheels with a thermostat to turn it off when the moving air drops below a set temp for cloudy days and nights. He could make one for his forklift batteries to keep them warmer than the outside air, so they operate more efficiently. Another for the RV golf cart batteries. Another for heating wash/shower water to a small degree. ElectroPig, great idea.
What's your input, Troy? :?:

techman
Site Admin
Posts: 1323
Joined: Thu Dec 22, 2011 11:49 am

Re: Solar furnace

Post by techman » Wed Feb 11, 2015 5:26 pm

Thank you for sharing that here. Yes it is a problem for me to keep up on the comments after 24 hours. The forum is always here and searchable. I love it. And it feels safe here if you know what I mean.

I hope to have a lot of passive solar heating projects going on for next winter. This year the house took up all my time.

I had heated my old camper three years ago with a very simple passive solar heater. Cardboard with foil taped on it. Painted black. Cut a hole in the top and bottom. Put it in your south facing window. Had my camper heated at around 50 to 70 degrees with that all day.

But when I moved the camper there was no more morning sun due to the trees.

The_Amateur
Posts: 56
Joined: Sat Nov 02, 2013 9:17 pm
Location: NW Atlanta

Re: Solar furnace

Post by The_Amateur » Wed Feb 11, 2015 7:08 pm

I would completely recommend anybody who wants to try it as a backup heat source, even for on-grid homes. I built one and it was finished December of last year I think and I would definitely go through the trouble to make it again.

I used 50 something cans to make my "Sprite can heater" as I call it since it is composed of all but 2 or 3 Sprite cans. I spray painted it black, siliconed some big leak areas, and covered it in plexiglas. It works excellently, bringing in 40-50 something degree air to convert to 90-120 degree air on sunny days that can bring the temperature from the 40s to the upper 70s inside. It does take time to heat, obviously, but it really works well. Just try to make these to size. My 30 square feet, 4 feet ceiling off-grid playground experiment is now heated by this heater primarily and my 300/350 watt electric heater is a night/cloudy day supplement heater. I'm really satisfied with it.

techman
Site Admin
Posts: 1323
Joined: Thu Dec 22, 2011 11:49 am

Re: Solar furnace

Post by techman » Mon Feb 16, 2015 8:58 pm

If you have a video on it, please post the link here. Thanks.

I have not seen all of your videos yet. You are starting to really turn them out :)

The_Amateur
Posts: 56
Joined: Sat Nov 02, 2013 9:17 pm
Location: NW Atlanta

Re: Solar furnace

Post by The_Amateur » Mon Feb 16, 2015 11:20 pm

I'm trying to do something constantly worth uploading. If not, I get real bored, hence part of the reason why I even did the playground project. I have a feeling they're going to be slowing down soon with upcoming rain/ice/snow again next weekend.

I recently just made a playlist about my passive heater construction. The videos at least mention it, and I'm watching them all now to make sure it's all truly relevant. If not, it'll be gone soon. Some may be quiet since I don't think I amplified the noise at that time yet.

https://www.youtube.com/watch?v=NabJuzv ... zaMiQJ41vz" onclick="window.open(this.href);return false;

If anybody reading this lives pretty much north of the GA/TN border on that latitude or is in cloudy climate anywhere, I would advise the intake be connected to a pipe as well, since it doesn't work nearly as well on colder, sunny days as it does on 35+ degree days.

techman
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Joined: Thu Dec 22, 2011 11:49 am

Re: Solar furnace

Post by techman » Thu Feb 26, 2015 10:23 pm

If you insulate the solar heater on the sides and bottom it will perform better. It will be able to retain more of its heat and transfer it to your interior.

I did not catch it on video but did you plan to paint the cans black?

The_Amateur
Posts: 56
Joined: Sat Nov 02, 2013 9:17 pm
Location: NW Atlanta

Re: Solar furnace

Post by The_Amateur » Thu Feb 26, 2015 10:36 pm

techman wrote:If you insulate the solar heater on the sides and bottom it will perform better. It will be able to retain more of its heat and transfer it to your interior.

I did not catch it on video but did you plan to paint the cans black?
The cans are spray painted black now if you saw where they were gray, but it was fixed the following day. They're not 100% perfectly black since the paint wasn't sticking all the way so some slight parts of the heater reveal the sprite cans' logos, etc. The heater is mostly black and from a distance looks completely black. It has worked well enough for now so I just left it. For next winter or if it gets cold again, I'll spray paint it with a third coat. Tomorrow is the last really cold day before the highs don't go below the upper 40s and the heater can bring the place into the 70s easily with 40s and sunny out. Insulation was considered but I didn't think it would matter so much besides if I did the insulation on the dryer hose going into the place.

It looks like this today:

http://imgur.com/4whj2Mw" onclick="window.open(this.href);return false; The window in the background is now hinged, but that's not relevant to the heating.

techman
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Re: Solar furnace

Post by techman » Sat Feb 28, 2015 12:04 pm

Ok, good.

My plan for this spring is to build a full sized greenhouse in front of the tiny home. This entire thing will be a solar heater for my home next winter. It will be screened for summer to let the heat out.

nailgunrecords
Posts: 2
Joined: Mon Aug 29, 2016 11:33 am

Re: Solar furnace

Post by nailgunrecords » Mon Aug 29, 2016 5:45 pm

Hey.
Ive been thinking about this design/project for a while and have a few thoughts to throw out there, (to see if you guys think it will work or not)

So, main construction would be as normal for 'tin can heating panels' but
- could corrugated roofing sheet be used? the cans would site nicely in the channels, keeping everything aligned. but would the lack of air gap between the plastic sheeting and the cans reduce efficiency?

- then could these panels then be used to roof the porch im planning to build on my camper? I would attach hot air ducting to the top edge of the panels to distribute the warm air inside,

crazy ideas i know, just how my brain ticks. ANy thoughts or comments greatly appreciated. :D

techman
Site Admin
Posts: 1323
Joined: Thu Dec 22, 2011 11:49 am

Re: Solar furnace

Post by techman » Sun Dec 11, 2016 10:49 am

The corrugated panel idea is pretty cool but it would present a problem with ducting out of it. You would have to put your ducts on the side framing rather than the bottom of the panels due to the corrugated panels.

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