My pod now has a new heating system: Hot water heating. I made a heater core, HWT doubles as boiler also put in 2 computer fans and an inline water pump. It's super quiet, only draws 1 amp, I'm very happy with it.

Would like to see more pics on where and how you tapped the hot water source and where the pump is located, the pump used, and pump control is. 

fred

 The heater is thermostat controlled, I can bypass the heater core by closing 2 valves in and out of the HWT. I can also switch off the pump or the fans. The nice part about that is that I can run the fans just for air circulation. The air gets picked up through the vent under the shower, therefor I made the hole

bigger. The big silver blob you see in front of the HWT is the inline water pump. The heater itself is in the outside storage.

  

   

 

 

I use a 12 volt inline hot water pump TE091.

The thermostat is a cheap Honeywell for a furnace.

Dewinterizing: I just blow out the lines.

love this idea! Nice work.

I'm pulling together parts for the hot water heat exchanger, What size exchanger did you use?

and any update on long term use and feasibility?

 Thanks, John

I used 2 length of baseboard heater elements, cut it in half so I had 4 pieces and staked them. I also made one change, I opened up the heater core so it is more exposed. The only other thing I would change is to put aluminum foil behind the coils to reflect the heat out. 

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Thanks for the pictures and help. This should be fun and it's such a great idea!

 Your heater core looks like 12" x 8" ? 

I found this 12 x 8 on ebay for $36 and it's on it's way, and I Have the other parts already.

 Still noodling out how to power the pump and fans with a thermostat, does the thermostat send good 12v to the pump and fans or did you use a relay?  

Thanks again, John

Thanks for the info! I finally put it all together and it works very well. I used an 8 x 8 heater core and a 3 speed 8" computer fan that blows the air from the back side.  I hooked a switch up that allows me to use either the new exchanger/fan or the regular furnace on the original thermostat. It's just temped in, (not pretty yet), until I can test it for real, It's been 80 degrees the last 5 days and 60 at night, not the best for testing.

Thanks again, John

Hi voisj, do you have the parts list you used for this project?

Bought the main items from EBAY.

I used a three speed fan so it could be quieter if necessary, (was not necessary as these things are really quiet.)  

Home depot

1/2" pex tubing 2 - 10' pieces.

sharkbite tee fitting - 2

sharkbite 1/2" valves - 2 

sharkbite (1/2") to male thread fittings - 4 (2 for pump and 2 for heat exchanger)

copper 1" to 1/2" female reducer fittings -2  ( soldered to the heat exchanger pipes, had 1" copper in/out).

24 x24 sheet of tin (to box in heat exchanger).

$12 cheap thermostat

heat wrap.

Thats it.

I was going for a simple system.

Return air comes in through the existing furnace return air holes.

I drew from the cold line into the WH as I always had air in the top of the tank and this solved the crazy pump/gurgling sound  problem.

I found full time 12v power at the furnace.

I put a shut off on both the in and out. (after these pics)  I needed a shutoff for the in side because convection kept the water moving if I didn't. The out side was just so I could isolate the system for repairs or whatever.

It's still operating perfect i'm told in Santa Barbara they never even use the furnace. But then it's never really cold there.

Third picture. I used a scrap piece of 1/4"plywood to replace the veneer for the new panel in case I needed to go back to stock. Turns out Rustoleum hammered bronze spray paint matched perfect. And you can see the valve I used to shut off convection flow. You need this, My wife made me shut it off when she showered because it messed with the hot water SOMETIMES,(never happened to me) you could just add a check valve on the cold line and it would solve this.

Hit the SLOPODMODS link by my signature, about halfway down the page 1 is a video link.

Any more questions, let me know.

rgds John

Looks like you put the heat exchanger link in twice instead of the water pump link?

 Thanks,fixed the link.

 I feel it worked fine,  it is only a computer fan so it wont heat it up from cold to 60 fast at all. But a good amount of air blows out of the grill, the fan specs claim 135 cfm.  We use the furnace to bump it up in the morning or to warm it up fast after being out.  This unit kept the pod near 60 at 37 degrees one night and it ran all night. SO much better than the loud furnace going off and on

 Marwayne used a modified baseboard heater so it would not restrict the flow as much, this would work better in a colder climate, most places we camp rarely get below the mid 40's at night.

Cheers John

Awesome! Thank you!

I think this hot water heating systems is the cat's pajamas but I wonder if it puts out any more heat than the Wave 3 propane heater I've installed that draws 0 amps.

I'm not knocking the hot water heating system at all......just wondering.

Got pictures/howto?

In terms of heating potential assuming 100% efficiency of the heat transfer the maximum is around 12000 BTU  or whatever the capability of the hot water heater is.  Even assuming pretty crappy efficiency it is going to be able to put out way more heat then a wave3 3000 btu - minus the heat that goes out the window.  Plus lots of people won't use the wave3 at night out of fear of killing themselves from oxygen deprivation (also scared of CO, but that is more paranoia).  

By the way, the wave3 is a fire hazard. I damn near lit my camper on fire once, by dropping a pillow off the bed and it took a bad bounce and leaned up against the heater.  It filled the camper with smoke fast!  It is also very good at melting sleeping bags.  Also from experience I would recommend the Wave6 over the Wave3 for increased power output.

The catalytic heaters work great and are silent or nearly so. But some of us are either concerned about and/or allergic to breathing combustion products. The hot water systems solve that issue. Also, FWIW, since the water heater can be heated by either propane or 120Vac electric it can be used either on or off grid, which could save carrying around an electric box heater. 

My issue with this solution is the need to winterize and dewinterize everytime I go out.  What I really want is a separate hot water heater filled with propolene glycol slaved to a much larger heat exchanger with a high volume low velocity fan or fans.  Fans speed could be continuously varied to keep a constant temperature.  No more temperature going up and down all the time, no large blower noise, just quiet continuous heat.  Can somebody please make that??  AquaHot has something similar, but expensive and 40k BTU, which is over kill.

Of course you could just fill up the hot water tank for the winter with the pink stuff and put in bypass valve so it does not accidentally come out the sink when you knock the tap with your elbow.

Or better yet don't drain the fresh water system at all and use a solenoid on a thermostat to run a little warm water back through the fresh tank and water pump feed line. That's what others have done and I plan to do. 

I installed a T in the propane line to the stove and a flexible rubber propane hose with a quick disconnect on the end to beneath the refrigerator.  The Wave 3 connects to that quick disconnect.

https://www.propexheatsource.co.uk/

I chose the Wave 3 because I also use it in my truck camper.  That's why I used quick-disconnect fittings, so I could swap it between the RPod and the camper.  I've slept with it running and yes, with a window slightly open for fresh air.....just in case.

I think a Wave 6 would be too much heat for us.

And I did look at the PlatCat but wanted something I could move about.

Everything is a fire hazard and the built-in furnace could malfunction, producing CO as well.

My main reasons for going with a Wave 3:

-no battery drain

-no jet engine noise from the furnace

-portability between RPod and truck camper

-reputation of the Wave heaters as safe when used properly

We do 95% of our camping where there's no power.

Very unlikely that the furnace could produce combustion products in the trailer, that's what the sail switch is there to assure against. 

The furnace draws 2 amps when running. If its on a 15% duty cycle, which should be roughly the equivalent of the Wave 3 running continuously (3000 btu/hr/20000 BTU/hr), that's about 7 amphours a day. Not a huge deal. Of course if you set your thermostat higher and the furnace runs all the time then thats 48 AH/day and that will kill your batteries pretty quickly. 

But all this is secondary if you are allergic to propane combustion products. My eyes get red and itchy and I get headaches when I run a propane appliance in an enclosed space. I always leave the door open and the roof fan on when using the stove. 

OTOH, if the combustion products from the Wave 3 don't bother you and you're careful to ventilate and keep flammable items away from it then its a fine solution.  

Thank you, John. I completed my system as well. The only thing left is the vent cover. 

Your instructions helped a lot!

Here is the complete, picture happy, build process 

http://photos.app.goo.gl/1XLm5ThZP4QmkZnx9 - https://photos.app.goo.gl/1XLm5ThZP4QmkZnx9

I hope to test it in a month or two.

Max

It's right where water heater bypass valves are. I set it up so it pulls water out of the exchanger and pushes it into the hot water line 

Water Pump ->  https://goo.gl/g8b5ug - https://goo.gl/g8b5ug

 Well done! ,

 its not as compicated or difficult to build and install as it looks, you just have to go for it!

And what is the performance like? have you done any tests?

Love the pictures good job!

rgds John

No tests yet. It's getting freezing here in MA. The camper is winterized and water heater is drained. I might drive some place warm in a couple of month though.

John, where did you get that vent cover? I cannot find anything that fits well

Awesome! Thank you