Water heater as a furnace?

[Dakodu]

Hi, iīm building a camper, and where i live we donīt need furnaces, itīs not that cold, but itīs still nice to have one, but even the smallest one is way to big for our wheather, i installed one on a camper that i build for my father and he turns it on for only 10 minutes at nights and early mornings, i think itīs a waste.
So i was thinking about using the water heater as a furnace, first i thought of installing a pump and radiator to have a second loop, but maybe i can just take out the water heater insulation and force air arround it with a coulple of silent fans.
I would only turn the heater on when i want heat or a shower and i would still put insullation around it, just a little bigger, leaving an inch or two free arround it for the air to pass.
Has anyone done something like this?
What do you guys think of this? my only concern would be shortering the life of the tank becouse of corrosion, maybe a could paint it with something to protect it more
Thanks.
Francisco.

[dwh]

Should work fine. Similar to the "calorifier" setup used with hydronic heaters.

http://www.xor.org.uk/unimog/mymog/heating.htm

Note how he set his up to make the air rise to the top for easier bleeding of the heating system.

[Jeff Wanamog]

I can't tell where you live, but you might want to look into a Truma Combi E.
Hard to find in the US. Worth the effort.
It is a combination water heater and furnace.

Jeff

[Kohburn]

with a couple of water/water heat exchangers and control valves you can have the standard electric/propane water heater that can also be circulated through a heat exchanger to take heat from the engines coolant, and/or it can circulate through another heat exchanger to circulate water through a blown air heater (or radiant heating if you want to get fancy)

when using water to heat you have almost unlimited methods of heating it. I've even seen people run a whip of hose to a stainless coil that they would drop into a campfire nearby (just keep the water circulating or things can start boiling/melting, some testing and keeping a close eye on the water temp are also important)

[mattressstx]

As you told here that your weather is not that cold then I think opting camper as a furnace is a good option. It not only saves your money but you can also make double use of a single thing. Go for it and ya, update about the experience here surely.

[Tony LEE]

It isn't just a question of where you are living, but more one of where you are likely to use the camper.

Doesn't take much of a drive to end up several thousand feet up where it might be a lot colder and where the snow hangs around until May or June.

I would question whether you could extract enough heat from a large, smooth cylinder when you compare it to the huge fin area of a typical fan-forced radiator.

I know of one travel-trailer (caravan in Oz-talk) owner who has a gas-fired HWS and he fitted a circulating pump and piping to a fan unit and he seems satisfied with the performance. How satisfied he would be in a howling gale at an ambient of below freezing might be a different matter though

[Ozarker]

Why not look into a radiant heater, the panel attaches to a wall. Depending on what your floor surface is or walls you might consider radiant tubing. Might rig up an electrical backup or auxilary burner too. Wish cooling options were as easy as heating options available.

[Treenail]

This is a great idea.

A friend of mine who is a housebuilder had a baseboard heater system in his house which used the house water heater as the heat source. His house is about 40 miles north of Minneapolis...cold weather country! When we talked about the setup all he had to do was some simple, for him, heat need/loss calculations. He said that he would likely burn out his water heater earlier but maybe not.

This sort of setup makes a lot of sense for a camper. If you decide you NEED a water heater adding a heater core from a junk yard care is simple. Wiring in a thermostat shouldn't be complicated either.