Furnace idea.

[mikeschn]

Here's my 2nd attempt at a cookie tin candle heater... After about 10 minutes the temp in the chamber above the candles stabilized at 169°F. Both the top and the front are uncomfortably warm. The two tins on the right don't have any practical purpose at the moment that I can tell...

Oh, you probably can't tell, but that's a piece of lexan in the glued into the lid of the lower chamber. I had to do that to make sure the candles didn't go out. It's kinda nice though! I think I would keep that feature.



Mike...

[rowerwet]

I think you want the candles in the tin with the air inlet, the rest are just for heat exchanging area,
how high did you put the interconnect holes between the boxes? the lower the better I think, just like the exhaust hole should be on the bottom of the box to trap any heat in the last box.
169 degrees with 150 btu of input is that the inside temp of the box or the exterior temp?

[Ron Dickey]

Here's my 2nd attempt at a cookie tin candle heater... After about 10 minutes the temp in the chamber above the candles stabilized at 169°F. Both the top and the front are uncomfortably warm. The two tins on the right don't have any practical purpose at the moment that I can tell...

Oh, you probably can't tell, but that's a piece of lexan in the glued into the lid of the lower chamber. I had to do that to make sure the candles didn't go out. It's kinda nice though! I think I would keep that feature.



Mike...

What is the temp with only one candle?

you could put some socks or raise bread, or heat a cub of tea, etc.

Mike you could put these in those shelters you are making!

[rowerwet]

too bad we have to reinvent all this, back in the 50's manufacturers made camper size floor furnaces, basically a box with a pilot light and a propane log, the bigger lousy insulated RV's killed them and everyone went to furnaces with blowers.
Floor furnaces in houses require no electricity, a thermocouple in the pilot light flame generates the electricty needed for the thermostat. My parents cabin in Maine has one, my wife and I lived there our first year and a half we were married, with a fan sitting on the floor mounted heater vent (it is mounted below the floor) we were comfortable through a Maine winter and a half (we bought our first house then).
They don't make them small enough today, or certify them for trailers.
Mounting this candle heater idea under the floor, vented through the floor(foot well?) would make sure the heat went all the way to the floor of the tear.

[mikeschn]

Rowerwet,

To answer your questions... the holes are in the middle...



And see, this is why I am asking you guys... I thought we were supposed to create a nice draft, like a fireplace. So logically I placed the exhaust at the very top. I can move it to the bottom if that'll keep more heat inside.

Yep, I guess we are reinventing stuff... I am not familiar with floor furnaces. Do you think they would work in a teardrop?

Mike...

P.S. That's the temp inside the top cookie tin!

[mikeschn]

Okay, did a little rearranging. 2 candles in each combustion chamber. The heat radiation chambers have cooled down to just under 140°F, which means they can be touched without getting burned.



Mike...

P.S. The wax in the top part of the candle has liquified. I hope this is not going to be a problem... eg the wick falling in and dousing the flame.

[Esteban]

Here is the YouTube Martiangod suggested


Looking for similar YouTubes led me to find tacticalintelligence.net/blog/how-to-make-a-candle-heater which has an extensive discussion about how to make candle heaters.

Google images for candle heater tin can

motherearthnews.com/diy/survival-heater

ebay automobile heater boxes wonder if any auto parts could be re-purposed?

littleguy.vanillaforums.com/discussion/451/candle-light-heater

rei.com uco-candlelier-candle-lantern was linked to in the little guy forum. This candle lantern or a similar one might be hung from a hook in the ceiling to provide light and warmth inside a teardrop.

[Martiangod]

Another alternative to the candle may be Sterno, gelled alcohol,
They now make gelled alchol firplaced that you can put anywhere in your home.
Wouldn't want to use for long term heat source, but for warming up a little trailer may work well

[mikeschn]

How many BTUs does a can of gelled sterno put out? And how long does it last?

Mike...

[Martiangod]

depends on theproduct selected, there are wick cans that seem to have longer burn times, and you can make your own gelled fuel, burn times and recipes are in this link

http://zenstoves.net/Sterno.htm

Good quality gell fuel up to 9000 BTU's

[mikeschn]

Good link Chris... good info on burn times and sizes. No BTUs though...

I guess I'll have to get a bigger cookie tin and test it...

Mike...

[RandyG]

I have made a few alcohol burners out of old coke cans, they will run for a while before you need to add fuel. Regular first aid alcohol is cheap and it is a fun project to make em. It would also be a good back up if you need to cook or boil water. Not so sure how yall feel about having it in your camper though, if it gets flipped over it would do lots of damage.

[GerryS]

I'd. E careful thinking about alcohol....two reasons

1) it's liquid. Spills are easy to do.
2) it burns nearly invisible.

You could easily turn a cold night into a very hot one. I'm not sure I'm even comfortable with candles....flame is a powerful tool. The more powerful a tool, the greater it's destructive potential.

[GPW]

What about an insulated candle box that goes outside and away from the trailer and feeds clean air (heated) into the cabin via an insulated tube ... No fumes , no candle smell inside ...

[KCStudly]

I was assuming that the tight fitting cookie tins would do an adequate job of keeping the wax fumes and soot out of the cabin when in operation. Maybe a little would be present when initially lighting, and if you wanted to snuff it out for some reason (some leather glove might be a good idea for handling the hot tin... keep it away from any synthetic bedding, curtains, whatever... although the lids would likely cool rapidly once removed, unless they have a big whomping heat sink attached to the inside of the lid) using a candle snuffer, or small candle holder lid to snuff out the candle (as opposed to just blowing it out) would also cut back dramatically on the fumes.

I'm curious about Mike's comment about the first and forth chambers not contributing; were they just not very hot at all when using the second tin as the burn chamber and reading temp. at the third?

When adding the additional 2 candles to the first chamber the temperature went down. Do you think that this was due to the flow rate going up and there being less effective heat transfer (i.e. more heat lose going out the vent)? Surely there were more BTU's being produced.