Water Heater, forced air heating system idea

[Airspeed]

I am getting ready to install a small propane water heater in my tear and I am thinking of using it as part of a heating system as well. My idea is to install a heater core out of a car or truck, they can be had brand new for as little as $15 at Napa, anyway, I would build a vent in the galley wall and make a small insulated sheet metal cabinet that the heater core would be mounted in, recirculate the heated water through the core and water heater with a small water pump, (if done right the water could be circulated through convection alone) and use a small cooling fan to recirculate the heated air through the core, into the cabin and back through the core.
I think this would be a very efficient heating system, small water pumps use very little electricity as do small 12 volt cooling fans.
This type of heating system could be easily controlled thermostatically as well so once you set the temp it would be automatic and save lots of energy.
Do any of you see any reason why this would not work well?
I am open to suggestions! Thanks, Aaron

[Nitetimes]

Do any of you see any reason why this would not work well?
I am open to suggestions! Thanks, Aaron

Nope, let's see the prototype!!!

[Airspeed]

I will have to get started on it! Now, if it works as planned I dont want to see one of you guys marketing my super duper heater without giving me some cash for the idea! Aaron

[jeepr]

I think it would work, a lot of houses have hot water/steam heat. The only question I have is how do you plan on recirculating the water? House systems are closed systems. Would it just circulate constantly? Any controls?

[madjack]

Aaron, I have thought about the same system for a number of years...as a plumber inna different life, let me add my 2cents worth....
A) pumps are usually designed to use the water pumped to cool the pump...pumping hot water kinda messes with this design feature
B) unless shore power is available(then use a small ceramic heater) power consumption of the pump becomes an issue unless you can control it thermostatically
C) convection would be the best way...place heater core above tank level, connect one side to top of H2O heater and the other to the bottom...make sure the connections are actually top and bottom, internally in the tank.....
D) enjoy the warmth!!!!!!!!!!!!!!!!!!!!!!!!!!
madjack

[jimqpublic]

Didn't we just have a thread on this?

Anyway the best pump I've read about for this is the El Sid line from Ivan Labs for $200+. Good heater cores with very low amp fans from Heatercraft are about $200 as well.

For a space as small as a teardrop I have another idea:
Just pop the top styrofoam cover off the water heater and allow for gravity (convective) airflow to circulate the heat off the tank itself.

I did this in our Chalet and though it doesn't really heat the trailer, it does keep the cold end a bit warmer.

[Airspeed]

I found a low voltage,low wattage pump that would work great and heat would be no issue, I would use one just like the filter pump in my hot tub. It is thermostatically controlled and pumps hot water with no problem.
I think a $15 heater core from napa would be more than adequate. I bought one last year to replace a leaky one in my full size Bazer. It heats the entire interior of my Blazer with no problem so I think it would heat the smaller, better insulated interior of the tear even though the water temp would be set lower than the 180 degrees that comes off the engine. The fan would be a 12 volt muffin fan, they are very quiet and use very little juice. I also found a heater core with fan built in for $29, it ia a little smaller and meant for cooling computers, two of them might work great.

[bdosborn]

Didn't we just have a thread on this?

Yup
Linky

Bruce

[Airspeed]

I wish I would have seen that! I guess great minds think alike! Aaron

[brian_bp]

I have seen a system described in another forum which used a regular RV water heater in a design similar to that proposed here, and it reportedly worked well.

One caution: domestic water heaters (household or RV) are not intended to operate continuously. A friend of mine has a solar heating system in his home, with a heated water storage tank as an "energy bank". He initially used a regular home water heater as a supplemental heat source, taking water from the tank and returning it heated. The storage tank is large, so once the heater ran continuously for an extended period (as if someone opened a hot water tap and just left it going for an unreasonably long time) and some points within the heater got too hot, and it failed - catastrophically, as in flooded basement. He got a real "boiler" intended for the purpose after that.

I would want to ensure that the water heater was up to the task, and maybe check with the manufacturer about an acceptable duty cycle.

[Juneaudave]

Not to throw a wet blanket on this thread (I like the thought), but I've had some cold weather camper experience and my problem with the whole thing is the maintenance required to drain the lines and keep everything from freezing when not in use or towing.

A tear is pretty small, and shouldn't be hard to heat. After coming up with several similar ideas, I think I am leaning towards a small electric heater and a generator when off the grid.

[coal_burner]

Cease!!! Desist!!!!!


The concept is sound.
Convection would easily negate the need for A pump.(I just ran the math)

BUT

The reeeeaaaalllllyyy big problem is that car radiators and heater cores are usually soldered together with A fifty percent lead solder.
You would be warm, but if you drank the water your lips would turn blue, your brain power would go down, and you might just die.

I knew A guy who contracted lead poisoning from the pipes in his house. He had to go to the doctor for regular bone scrapings to get the lead out of him as thats where it tends to concentrate. This guy got a lot of shrapnel in him in korea, and he said that that pain was nothing compared to a bone scraping session.

[demtears]

I like the idea! But the idea I had about heating was also using a automotive heater core or an auxilary heater core used in tractors. The idea or concept was the same as rear heat in a van, I was thinking about having quick connect couplers that would connect water heater hoses from couplers on the vehicle to coupler ports on the tear the ones when they are disconnected they re- seal so no, to minimal leakage. Still thinking about the idea or has it already been used any thoughts on this.

[bdosborn]

So how about an aluminum heater core? Aren't they welded instead of soldered?
Bruce