Free Heat

[polecat77]

I was wondering if anyone thinks this would work for heat in the winter months http://www.cansolair.com Pleas check it out and let me know. I was thinking of calling and asking if they could make one to fit the door on a Transvan

 

[dragonflyinthesky]

<P><b>Sounds interesting. Expensive-what isn't?.&nbsp; If it would help on fuel oil bills that would be great.&nbsp; I heat my house with fuel oil and wood.&nbsp; The wood saves lots of money but it is not always free.&nbsp; Maybe the company will see a need to modify for our mobile uses.&nbsp; I will contact them as well to try to get some interest in our needs.&nbsp; On the other hand, yesterdays 40 degrees formed an ice skating rink here and I think I will keep my sights set on somewhere I don't need a heater.</b></P>

 

[blars]

The fan will use some energy, so it isn't free to run.&nbsp; RV furnace fans can be a significant battery drain, and they aren't "super-powerful".&nbsp; How big is it, and how many BTU's per hour of sunlight do you get?&nbsp; While the claims may be true (under limited circumstances), they sound optomistic (if not fradulent) to me.<br>

 

[polecat77]

going to contact them to see if they can rig up something for me. I heard about them on a morning show long time ago.&nbsp;

 

[Elseanno]

I think it would work just fine. Might be costly or tricky to build as connecting those cans could be tricky. Still, it would work just fine on a van or rv roof.<br><br>You can also make a solar water heater by doing the same thing with that black poly tubing they sell in flat rolls for landscaping. (think lowes/home depot) Encase part of a roll in a box like the cans. Pump water through during daylight hours.(could use solar powered pump) You should probably have a heat exchanger in a small (say 5 gallon) food safe insulated vessel, assuming you want to be able to drink it. If it's just for washing, don't bother with the heat exchanger or worry about food safe.<br><br>There would need to be provisions for filling and draining. You could easily work those out. <br><br>Certainly wouldn't want to leave it unattended on cold nights as it might freeze and rupture. If that is a regular issue, maybe the heat exchanger for a closed loop would be better. Just ad some antifreeze to the mix, propylene glycol is much safer in case of leak than ethylene glycol.<br><br>Oooh! Here's a YouTube video of the basic idea. Might be able to use a larger version for heating air..<br><br><br><br>Good luck!<br><br>Elseanno<br><br><br><br>

 

[Elseanno]

A little more searching on youtube revealed step by steps instructions on the sodapop can heater.<br><br><br><br>Elseanno<br><br>

 

[sputnik]

This thread's a little old, but winter approaches, so here goes.<div>I've been researching solar space heaters for several years on &amp; off and this year I'm gonna make it, by golly.</div><div>The beer can heaters, they're sexy, but not the best method if you are going to go through the trouble of making a heater from scratch. &nbsp;If you're in a permanent home with lots of room, heck, make way too much sq. footage of those, they'll work. &nbsp;But in vehicles, space for such things are limited. &nbsp;They get a lot of web coverage because of the "cool" aspect, but they are ALOT of work.</div><div>IMHO, in my years of searching, I have found the best info at 3 places. &nbsp;</div><div>#1, <a href="http://tech.groups.yahoo.com/group/SimplySolar/" target="_blank">yahoo group SimplySolar</a>, they are great, lots of experience from lots of people and real research, not simply "hey, I drunk all these beers and made a heater, works!"</div><div>#2 <a href="http://www.builditsolar.com/" target="_blank">Builditsolar.com</a>, the website owner Gary is also a member of SimplySolar, the info bleeds over back &amp; forth.</div><div>#3 <a href="http://www.redrok.com/main.htm" target="_blank">Redrok.com</a>, this guy makes &amp; sells sun tracking controllers, gives the info away if you want to try &amp; duplicate without buying. &nbsp;He's also got lots of good info, although it's not organized for easy searching.</div><div>All three of these are very knowledgeable, helpful, non-profit oriented sources.</div><div>If you read through the posts at SimplySolar you will soon find that the most effective "breadbox" type space heater is also the easiest and also the cheapest next to the beer can idea, unless you value your time at more than $.10/hr., then it beats the beer cans.</div><div><a href="http://www.builditsolar.com/Experimental/AirColTesting/ScreenCollector/Building.htm" target="_blank">What is it</a>? &nbsp;Charcoal black aluminum window screen, stapled 3 layers thick, .5 inch apart on a cheap wood frame. &nbsp;Just put that in the box instead of the beer cans. &nbsp;That lowly little window screen, got lots of surface area and air transferring thru gets alot of contact.</div><div>There is about 1KW of sun energy/sq. yard, decreasing as you go north. &nbsp;1 watt=3.41 btu. &nbsp;Most decent solar air space heaters are about 50% efficient, some a little more. &nbsp;So you can use that to figure out what you need.</div><div>I'm torn between the simplistic window screen heater and a design I've been working on that emulates the latest solar plants being made, called CLFR (not carriage return line feed, <a href="http://en.wikipedia.org/wiki/Compact_linear_Fresnel_reflector" target="_blank">Compact Linear Fresnel Reflector</a>). &nbsp;The screen heater is simple, cheap, but a bit bigger than I would like to cart around (2'x4' would probably work pretty good for me, like a big stereo speaker, but 6" deep). &nbsp;The CLFR design is smaller, but more expensive, more complex and a bigger footprint on my roof, as it is all mounted flat there. But very low wind load, which is nice. &nbsp;The "speaker" could go anywhere and although it's larger, still has about the same footprint, since it stands perpendicular to the sun, between 45 &amp; 60 degrees for me here. &nbsp;Gonna catch the wind like <a href="http://www.freakingnews.com/The-Flying-Nun-Pics-81653.asp" target="_blank">The Flying Nun</a>, but it can be tamed easily. &nbsp;And no tracking required, unless you want to squeeze every last btu out of the sun. &nbsp;The CLFR would require at least 1 tracker, and more if you want to completely automate it and get maximum efficiency.</div><div>Another intriguing design I explored recently, like the beer cans, using cheap recycled materials is what I call "The Atlantis Death Ray Heater." &nbsp;Cover a satellite dish with reflective mylar, build an absorber out of copper pipe painted black, point it at the sun. &nbsp;This will work well, but the 18" dishes available here in SoCal only seem to get about 700btu, I'd need a couple or a bigger dish. &nbsp;And many downsides: would attract ALOT of attention, not stealthy at all, atrocious wind load, must track the sun in 2 directions and finally, although they are quite efficient, would even boil water, produce steam, that kind of high heat is not required for this purpose, and the efficiency, although apparently awesome, actually goes down the hotter you get things, as now insulation, conduction &amp; convection become much more relevant losses than with a lower grade heat.</div><div>Well, that's a quick rundown of where I'm at on the issue. &nbsp;Food for thought, even if it's nonsense&nbsp;<img border="0" align="absmiddle" src="https://vanlivingforum.com/images/boards/smilies/wink.gif"></div><div><br></div>

 

[Wild_E]

you can get a solar fan, it only blows air when the solar is in operation, as when it is sunny.. then you can heat with other means at night time.

 

[sputnik]

For about $5 you can get a handful of simple button thermostats on ebay. &nbsp;Then fan doesn't come on until heater is warmed up. &nbsp;I use one of these for a fan up in my fridge chimney, works great.<div>I plan to use the same fan I use up there for the heater too. &nbsp;It's a computer fan, Panaflo 4", about 120cfm, something like that, with a speed control. &nbsp;Amazing output for a little fan like that, really happy with the job it does in the chimney. &nbsp;You can buy these cheaply from a seller on ebay, bootstosunshine, refurbished, whatever that means, mine have worked great.<br><div>I am concerned however that I will probably have to close the duct vent in the evening. &nbsp;Black bodies that suck up heat from the sun work just the reverse in the dark, happily radiating all your heat to the universe. &nbsp;In this case though, the black body is behind an insulating area, so I just don't know. &nbsp;Working on that right now, a simple plug would do though, or register vent grille using weatherstripping to make sure it REALLY closed. &nbsp;Something like that. &nbsp;Eventually would like to automate it though, then it could be warming in the morning even before waking. &nbsp;I'll have to look at some of those old Rube Goldberg cartoons...</div></div>

 

[Seraphim]

More ideas here:

http://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm#ActiveAir

Using metal flex tube would be easier than messing with all those soda cans. Check the site out. There are dozens of good designs. It also covets water heaters, heating with compost, evaporativevcoolers - a huge site.

 

[templedog]

well, here in ND... if I had those panels and brushed the snow off.. and the sun was beamin on them panels.. it doesn't seem to matter.. I think it would still be cold and the fan would be blowing in cold air. heh.. They don't look like they're for cold climates

 

[Guest]

<P>

well, here in ND... if I had those panels and brushed the snow off.. and the sun was beamin on them panels.. it doesn't seem to matter.. I think it would still be cold and the fan would be blowing in cold air. heh.. They don't look like they're for cold climates

</P>Do you mean the pop can panels? No, it would blow hot air because the sun will heat those cans pretty quick. It's on the cloudy days that it'll be a bit more crummy.<br><br>What I'm curious about is for people installing those permanently, how do they avoid the inevitible issue of summertime temperatures and hot sun?<br>

 

[Seraphim]

<P><A href="http://planetgreen.discovery.com/home-garden/solar-garage-furnace.html" target=_blank target=_blank>http://planetgreen.discovery.com/home-garden/solar-garage-furnace.html</A><BR>&nbsp;</P><br>These are the DIY plans with instructions and material list.<BR><br>

 

[Seraphim]

how do they avoid the inevitible issue of summertime temperatures and hot sun?<BR>&nbsp;

<br><br>They add a sauna.<br><br>I have to agree with templedog about the effectiveness of this in very cold weather.<br>