Hot water and hydronic heating

Yeah, for supplemental heat, an RV owner with forced air furnace might choose a different appliance. I already have a different appliance, a propane fired heater that is vented and uses no electricity.

I'm also thinking of this as supplemental heat rather than the main source. My goal is to bring the fresh water tank to an equilibrium between ice cold and room temperature. At the same time, I could be drawing a bit of supplemental heat from the system.

I was worried about any type of adverse conditions ensuing from using the potable water in a heating situation like mentioned. Roy B has the closest application to what I envision.

Well all in all it depends on the reasoning for trying to get a different heat source..

If staying on grid and just dont want to use propane I would say add an electric element to your RV heater...

see here

cheap heat.... RV systems

But many do it with the wave heaters so as to not use electric of the furnace fan and to reduce propane usage... This is for off grid..

How efficient is the water heater VS furnace? Are you going to be spending more on propane heating water then just running the furnace? If you are planning on electric, why not just get a oil filled heater?

All good caveats but maybe some more background is needed. I have a whole-house solution for heating. It is a vented 20K BTU heater, propane fired, that is efficient. It does not have a fan or need any power to operate. This is the third RV this heater has been in and is a tested-to- (-20f) solution.

What I'm about is taking some of the heated water from the onboard water heater and circulating it to the fresh water tank. This is similar to what member Profdant139 did here. I will hard plumb everything and don't need an exterior fill solution like he did, I have fittings on the steel fresh water tank.

I would also like to pull out a bit of heat through a heat exchanger and fan or baseboard heater. I don't expect it to anyway come near to a whole house solution for heating. If I can get 70f at the exchanger, I would be happy. I'm wondering if circulating the water like this will have any adverse effects like algae, contamination, etc. I'm not too worried about the latter as I already have a steel tank and deal with a little iron discoloration now and then. Filtration takes care of that. I'd also be interested if anybody has pump recommendations. I know member SMKettner has one of those magnetic vane pumps and likes it a lot. They are expensive, though.

It's been nearly 40 years since I did a lot of steam and hot water work but radiant is way more efficient because of the lower boiler temp and less stack loss. Using the WH for the heat source and cycling the fan coil unit with a t stat wouldn't be as efficient as a real low temp radiant system... if that help you any. Craig

C Schomer wrote:
It's been nearly 40 years since I did a lot of steam and hot water work but radiant is way more efficient because of the lower boiler temp and less stack loss. Using the WH for the heat source and cycling the fan coil unit with a t stat wouldn't be as efficient as a real low temp radiant system... if that help you any. Craig

Yes but with radiant you need triple the sq ft of tubing or more. Its not finned tube....

And where are you going to put that? In floor of RV and in all the walls and you probably still will not have enough heat..

Just my 2 cents...

The pictures of the first system are of my first attempt. I switched to an atwood 6 gallon water heater with 140* stat dedicated to heat, I think I can go up to 160 but didn't find it necessary. This way I can run coolant to protect the aluminum. Same heater core and fan setup, works wonderful in our 25' toy hauler. I consume 1/2 the propane and very little power, 2 6v batteries never fell below 12.3V. It's quiet and doesn't suck the moisture out of the air.

Todd,
What are you using for a pump?

topsflo ts5

toddb wrote:
topsflo ts5

Thank you!

I really don't know if I'll go forward with this as I am doing less camping in cold weather but it is nice to know it can be done (and successfully). This morning would be an excellent time to have this installed. Currently, it is 6f and the forecast calls for a dropping temp until tomorrow morning. Fortunately, I'll be inside the house day dreaming about this and watching millionaire football players freeze their keesters off, lol.;)