idea for homemade propane heater

[egjacks]

In my plans for a teardrop I have been trying to figure out how to heat it. I know that many people go without heat and simply have good insulation, or good blankets or only camp summer or whatever, but for the purpose of this thread I am taking it for granted that additional heat is desirable.
OK, so I have been kicking an idea around in my head ever since I saw this picture here on the forum

You've seen this one, right?



Mike...

So I was thinking about how to do a similar thing with propane. I have drawn up some potential plans but I am not so good at getting pictures of my own onto the internet, so I will try to describe what I am thinking in as much detail as possible:

Built into a teardrop wall, appropriately insulated from the wall with fiberglass or something so that there cannot be damage to the wall, is a metal box. This box is divided into two chambers down the middle of the wall so that the side of the box that is fully inside the trailer is COMPLETELY separated from the side that is in contact with the outside. Basically it would be something like two chambers, each approximately 2x10x10 butted up against each other.

In the outside chamber are vents to the outdoors in the top and bottom allowing fresh air to enter and exhaust gasses to vent. As a source of heat, I envision a cannibalized propane lantern or perhaps two of them located near the bottom of the chamber but in such a way that the valves that control the amount of propane would be able to be accessed from inside the trailer. The reason I thought of a lantern mantle as a source of heat was that it would be cheap and you could probably use it mostly intact. Above the lantern mantles would be a copper heat sink, perhaps stolen from a computer, located in such a way as to catch as much of the rising heat as possible. This heat sink would be mounted to the inside dividing wall perhaps with the copper passing through the wall but not in such a way that exhaust gasses could also pass through the wall. A similar heat sink would be mounted inside the inner chamber. Perhaps one like this one:


In the heat sink pictured the fan would force unheated inside trailer air through the sink, picking up heat and then pushing the warmed air back into the trailer. If you wanted, it seems like it would be simple to use a sink without an attached fan or perhaps add your own. For that matter convection alone might be enough to heat the inside of the trailer. Convection might be better for those who have limited or no battery, while the fans might be better with a 12v source of power.

I would also add a BBQ lighter as a source of ignition, and I think I would have a tiny glass observation window so that I could see if the lantern was lit.

If the lantern valves were sufficiently sensitive, you could have quite a lot of control over how hot the heater would get. And you could have two independent mantles so one or both could be lit at the same time, further controlling the temp. another option would be to add a rheostat to the fans for variable speed airflow over the heat sink.

Ok now I want to hear all the opinions on this project that I can get. My own thoughts are that I think that it would be safe. I think the lantern mantles would give off enough heat to warm the trailer, perhaps too much, but we would be losing quite a bit of heat with the exhaust gasses, so maybe it would be just right? I have no feel at all for what it would cost to fabricate. Since I can't seem to find a vented heater in a size small enough for a teardrop st nearly any price, certainly not one I can or want to pay, maybe price is a moot point. I could be wrong but I don't think it would cost more that $50, and potentially much less...especially if you had stuff laying around you could use. I don't think it would use up too much propane, especially if you could plumb it to a large refillable tank. I suppose how much propane used would depend on the type of lantern, how efficient you could make it -by which I mean how low you could set the lantern and still have adequate heat-, and what temperature was desired and how much that desired temperature differed from the ambient temps.

So... what do you think?

[Shadow Catcher]

The idea is good but the amount of heat will be miniscule. I have been playing with all sorts of ideas along this line i.e. some sort of external boiler (wood) with an inside heat exchanger. To scale it up to something usable use a couple of automotive heater cores.

[egjacks]

I am not so good with automotive things, but isn't a heater core just a heat sink? How would it make a difference? (honest question, I have no idea)

as far as the amount of heat that would be introduced into the teardrop, nearly every heater I have seen seems to be tremendously over powered for a tiny trailer. Are you saying that you think the heat will not be enough or that it would not be enough to be worth the amount of propane used?

It seems like miniscule might be just right for running while I am asleep, that way I would neither roast nor freeze...

[Treeview]

We're all looking for a perpetual motion machine. Where we can get every bit of energy out that went in with no loss.

Your idea of scavenging heat from a light source seems interesting but I wonder if there would be enough energy left to scavenge.

When burners, open flame or mantle, are designed I trust the engineers to have fabricated the most efficient method. In the case of a lantern I have to believe that there is energy used to make light instead of heat like in a stove or furnace. If you're using a lantern to grab heat there might not be as much leftover as you might find from a burner. I don't know that though.

Here's an idea for making a small, remote heater.

Use a propane soldering iron or small burner from a camping stove. Make a cover around the burner. Jacket that with a plenum or air chamber. Duct tubing around this plenum into the tent/camper. You could wire in a thermostat as well as a remote striker if you want to start the furnace from inside.

Burn gas--->make heat

Burn gas--->make light--->make heat

Eliminate one step

Or...get a good sleeping bag and synthetic jammies...cotton cools/kotton kills...add a thin stocking cap and glove liners to slip on when you wake up. It isn't hard to function without external heat down to the teens. [Add in all of the usual cautions here] I've camped in a pickup shell in below zero weather. I would use my stove to take the chill off before I went to sleep and when I was waking up. NEVER when I was asleep...even with venting. Need heat...get a cat or dog...or cuddly camping partner. And eat good food!

Tom

[Shadow Catcher]

radiators, heater, and AC cores are made to efficiently absorb/radiate heat by running a hot fluid through what amounts to a finned exchanger. The fins help extract the heat from a closed tube. Conventional propane heaters do not used fined exchangers and lose a great deal of heat in the exhaust.

[parnold]

I remember the day when I would heat the inside of a leaky pop-up trailer by lighting a lantern, so as far as the heat output, there is certainly more than enough heat energy for a tear drop. How much of that energy you can manage to transfer is the key. You could start off with something more simple, and just have the chimney pass into then out of the sleeping compartment, and decide from there if you need to get more complex with heat sinks. You could also go crazy and create a fluid filled system with baseboard heaters.

[Larry C]

I remember the day when I would heat the inside of a leaky pop-up trailer by lighting a lantern, so as far as the heat output, there is certainly more than enough heat energy for a tear drop. How much of that energy you can manage to transfer is the key. You could start off with something more simple, and just have the chimney pass into then out of the sleeping compartment, and decide from there if you need to get more complex with heat sinks. You could also go crazy and create a fluid filled system with baseboard heaters.

You know Paul, you may on to something with the hydronic heating system. Some of the infloor heating systems for small garages use a water heater for the hot water source instead of a boiler. What's the smallest propane water heater available? All you need is the water heater, a small circulator pump, maybe even 12V, and some form of radiator, either baseboard or some stand up type. This could really work!! All the combustion is outside in an insulated tank. Insulated hoses would run from the heater outlet through the radiator and back into water heater. Quick couplers used for connections. Everything is thermostatically controlled based on the water temp/heat demand. The water heater thermostat maintains a constant water temp. A thermostat in the trailer would control the circulator. Wow.. You could even have zones, one for your feet and one for your head You could even connect several Teardrops to one larger heater. Just tow a second trailer with heater and sell the heat at gatherings, just have enough hose to connect to the mother ship Central heating at a gathering, why not

I love it! thanks, Paul..

Larry C

[parnold]

Central heating at a gathering, why not

I love it! thanks, Paul..

Larry C

I want 5% of the profit!

[Larry C]

For those gatherings with a small group and has at least one electric site. This is just the ticket.
http://www.amazon.com/dp/B000W6AVMY/ref=asc_df_B000W6AVMY1898214?smid=A2JGH9K1780DGL&tag=nextagusmp0403800-20&linkCode=asn&creative=395105&creativeASIN=B000W6AVMY
Now I have to make a new floor with in-floor heating...

Paul: about the commission.. My people will contact your people

[Blotto Bros]

As a side form of income I design and maintain self service car washes. Ever wonder how we keep the floors of the bays from freezing into a sloped sheet of ice in the winter?

SIMPLE: A closed loop of tubes are laid when the floor is poured and hooked up to a TANKLESS hot water heater in the pump room. Thermostat outside set to ~40 and the water heaters\pumps only run when needed.

Do the same for your trailer with a small portable propane water heater. Run flex tubing (maybe PEX) in a zig zag pattern under your floor or maybe even to an old heater core inside your trailer. Next wire a thermostat inline with the battery powered 12v pump. Since many on demand hot water heaters only fire when they detect flow your only burning fuel when your thermostat calls for it.

I would also use RV or non toxic anti-freeze in this system to prevent late night freeze ups.

[eamarquardt]

Has anyone considered thermonuclear power.

See: http://en.wikipedia.org/wiki/Radioisoto ... _generator

Food for thought.

I've thought about one of these: http://www.sigmarine.com/SIG-CCH.html

but it seems a bit overpowered (as most heaters are for a teardrop. Also I have concerns about the clearance required from the floor and ceiling. A smaller version of something like this would be neat.

Cheers,

Gus

[egjacks]

OK, I took the time to sketch out my ideas in ms pain, I mean paint

I don't think using a lantern mantle would be that much of a problem, as far as creating light instead of heat, the mantle is simply a place for the propane to burn, although it does have phosphorescent qualities as well, but it is essentially a specialized burner very similar to a stove. I think X amount of propane burned in a lantern would give off the same BTUs as X amount of propane burned in a stove. Regardless, a different burner/heat source could easily be substituted.

A computer heat sink, although not necessarily as efficient at a fluid filled heater core, still have to be an efficient means of moving heat from one location to another. Otherwise computers would not function well (or possibly at all). However, Heat sink/heater core/etc could all be interchangeable as far as my idea goes. So long as it would be able to fit in the space constraints.

Here was my first idea: All the combustion and exhausts are kept on the outside of the trailer. Obviously you would lose a fair amount of heat in the exhausts but, having burned myself on lanterns several times, I can attest to the fact that they will heat nearby metal.



This idea is very similar to the first, I did not label anything because I thought it would be obvious from looking at the first picture.
the main difference is that the heat source and heat fins are taking better advantage of how heat rises.


PS. among several things I forgot to draw into the designs would be an access to change mantles or perform maintenance, and some sort of sealed observation window to be able to see if the burner was lit from the inside.

PPS. No concern whatsoever was given to actual scale of items, so somethings might seem out of perspective.

[egjacks]

I don't know how my wife would feel about camping with a Thermonuclear device... This might be a time where it is better to ask for forgiveness than permission?

[eamarquardt]

I don't know how my wife would feel about camping with a Thermonuclear device... This might be a time where it is better to ask for forgiveness than permission?

Tell your wife that an advantage of the thermonuclear powered heater is that you both will glow in the dark after spending a night in your trailer eliminating the need for lanterns, leds, incandescents, florescents, etc, etc, etc (to quote the king of Siam).

I don't think it would that terribly difficult buy one of the commercial heaters (like Southpennrailroad?) modify it a bit like folks have modified air conditioners with duct hoses and make it detachable.

If you have a shop one could manufacture a heat ss heat exchanger, scrounge up perhaps an old water heater burner with thermocouple and thermostat and cobble up your own heater. You'd probably have to make your own burner and us a much smaller jet but I'm sure it could be done.

Cheers,

Gus

[parnold]

Eric: I think you have a very viable idea there, and I'm looking forward to seeing your prototype. The beauty of your concept is it can be built out of very inexpensive material. Good luck and get crackin!