On board shower

[Tigglebitties]

When ball valve is turned to run the heat exchanger, the cabin heater will NOT warm up below 2,500 RPM.
I Let it idle for 20 min & nothing. No hot water, no hot air from the cabin heater.
Took a hot lap around the neighbourhood & kept it over 2500- then both worked great!
Kinda.
Once back in the driveway, and back at idle below 1,000 rpm,
That heat quickly left as I pulled about 30 seconds of hot water out of the shower head. Then back to cold.

I think it's that check valve- it's stamped 5 PSI
& it seems like the engine coolant pressure will not exceed that cracking pressure unless it's revved up.

Now what?
I need that check valve so the entire system can be bypassed with one turn of a handle- but that idiot proof nature seems to be destroyed by a shower that will not keep hot unless someone lays a brick on the gas pedal...


The goal here is to build your rig stronger than you are stupid.

 

[Xterabl]

Probably without the check valve, you need to have two ball valves instead of one. Can you fit two?
I have a similar heat exchanger setup, but with no check valves and no ball valves.
This is risky, of course, but I bought quality parts and I generally do pretty good work.
Only time will tell, regarding the soundness of my judgment

 

[jerdog53]

This is something I have been wanting to do so subscribed!

 

[Tigglebitties]

Subscribed - A lot of people like the heat exchanger for hot water. Its more compact, gets hotter, and doesn't need propane. Despite these advantages, I went with the Eccotemp E5 propane shower (for now). I was worried about adding a possible failure point to my cooling system, and I was also worried about scalding one of my young kids with 190F water!

The failure point, isn't a big deal if you carry all the needed parts and use metal fittings vs. plastic, but I'm interested to see how you regulate the water temperature.

with the bypass, I've plumbed in hose far stronger than the stock components, with stronger fittings and hose clamps etc, along with a three way ball valve rated at more than double the stress of pressure or temp. this system could ever reach.
out of principle, I will not trust the heat exchange's integrity never to fail like the bypass will not, so I get your skepticism on the exchange circuit.
as far as the whole don't scald the babies thing- check out a thermostatic mixing valve- AKA anti- scald valve. they're by law, manditory in california- they're designed so that you can set your home water heater to 200 degrees, then rest easy knowing that your kids can turn the shower to full heat and never be able to touch water above a pre-designated temperature. The valve mechanically regulates the mix of cold and hot water so that the output will never reach above whatever tempurature you set it as. I'll screw with this valve setting in the driveway until I get it to behave in a good range and from there, it will then only allow perfect temperature shower water out regardless of the input temp or engine temp.

 

[cwadej]

II too am looking at different options for hot water. I like the idea of te heat exchanger, in theory only though.
Must have a hot engine to use it

 

[cruiseroutfit]

II too am looking at different options for hot water. I like the idea of te heat exchanger, in theory only though.
Must have a hot engine to use it

I can understand the concern but I can tell you with my experience it has proven not to be a major issue. We like to shower at night and after we set up camp. It works out quite nicely to roll into camp (hot engine), let it idle of few minutes while heating up a 5 gallon water container. By the time it has heated up the container, we have camped set up and are ready to shower and get cleaned up. If your base camped for many days at the same place, it might be cumbersome and perhaps wasteful to have to warm up your engine to shower. I rarely stay in one place for that long so it hasn't impacted our travels.

 

[Tigglebitties]

II too am looking at different options for hot water. I like the idea of te heat exchanger, in theory only though.
Must have a hot engine to use it

I get your concerns, but think of it this way- a heat exchange is more than a novel concept- it takes the wasted loss in energy from your engine and captures it into useable hot water-

Any hot shower setup is going to require an external energy source. Now think of the strain it'll put on you to pack both that energy source (propane or wood) along with the system designed ONLY for capturing that energy (again, at a loss) to heat your shower water.

This thing takes an engine that moves your whole camp and pulls the lost energy - heat- that would be ultimately dispersed with your radiator cooling fan & converts it to something you truly need.

In theory and practice it is the closest thing to perfection you'll find as far as minimalistic survival design goes.

But.
Again, you DO need a running engine to heat it. Only saving grace there is that again, an external shower heat source is going to run at a loss of energy from the source. An engine will lose more & "waste" a bit more than a propane shower, but not so much more that would warrant packing in a Zodi unit.


The goal here is to build your rig stronger than you are stupid.

 

[Xterabl]

Good points by Tigglbitties.
It also makes a lot of sense if you use coleman (or other) dual fuel appliances (stove, lantern) and therefore the unleaded gas is very fungible and is good for locomotion, lighting, cooking, and cleaning.

Simplify.

 

[Tigglebitties]

IITTSSS ALIVE!!!!!

I deleted the check valve in place of a regular ball valve and it now works PERFECTLY!
I hooked up just the hot side with a hose & the water came through so hot that the thermostatic valve shut itself off.
Tee'd in to flow hot and cold from test hose and PERFECT water temp came out of the shower head.

I'm so damn excited. Now just to mount the pump / hoses & clean up install

The goal here is to build your rig stronger than you are stupid.

 

[jerdog53]

I need to understand this.

Incoming water is drawn into the pump and ejected and split into two lines one goes thru the heat exchanger and is heated and the other goes down stream of the heat exchanger to the mixing valve. The two different water temperatures are then combined manually at the mixing valve to a proper temperature.

Is this correct?

 

[Tigglebitties]

I need to understand this.

Incoming water is drawn into the pump and ejected and split into two lines one goes thru the heat exchanger and is heated and the other goes down stream of the heat exchanger to the mixing valve. The two different water temperatures are then combined manually at the mixing valve to a proper temperature.

Is this correct?

Correct.
I wouldn't say "manually" mixed- more like "analog" mixed- it's a mechanical spring/ witchcraft device that changes the amount allowed to pass through the hot/ cold inlets to the mixed output port by a set knob.

It's called an anti- scald valve & is normally meant to prevent your sink or shower from dispensing water as hot as your water heater , but is used here to set a maximum heat output which I set to a perfect level to shower in & never touch again or deal with knobs or have a variable output with cold stream water.
In theory, I could pull Ice water from a cooler and still get perfect hot water out.


The goal here is to build your rig stronger than you are stupid.

 

[Tigglebitties]

pump bracket

Mounted and plumbed

These two items are all I need to carry now!
RV shower head and a length of double female garden hose fittings- they stow easily in the cab and are just as easily replaced at a walmart if lost or broken.

The shower head screws onto the mixing valve up front and the double female goes into the pump

Throw it in a 5 gallon bucket & good to go!
Five gallons lasts just under 10 minutes- no pressure or temp drop. Kept the engine around 180 degrees as well.


Im proud of this one.

If you're stalking this thread, try it! It's not too difficult.


The goal here is to build your rig stronger than you are stupid.

 

[jerdog53]

Would you put a parts list together please?

 

[RubiChris]

Has anyone installed a Helton or similar heat exchanger in a JK? I'm particularly interested in where you located the heat exchanger.

Thanks!

 

[Tigglebitties]

PARTS

The helton units work, but take up more space and I read somewhere they're not as efficient as a plate heat exchange. no idea if this is true or not, but I can say the square plate type I got was very easy to mount rather than a round cylinder type and took less space.
I'll try and remember everything & keep this updated for a whole parts list and sources to buy them from
PART LIST:

Heat exchanger:
http://www.dudadiesel.com/
I bought it through amazon- I got a 40 plate exchanger which may be overkill, but at idle around 700 RPM, works perfectly and does not run cold even when used with a garden hose on full blast. I've read around that the smaller 20 plate exchanges need you to rev the idle up to 1500 or so not to run cold with a large water throughput.

All parts used were brass- fairly easy to find
two 1/2" brass Tee's

one three way 1/2" ball valve - McMaster Carr

40' of 1/2" multipurpose hose rated above 200 degrees - McMaster Carr

one 72" RV shower hose w/ rv showerhead - Amazon - real cheap, 15$ or so
one Anti Scald mixing valve - "Powers" brand off of amazon - BE CAREFUL ORDERING THIS! many are marked as M pt not N pt - be careful you don't get a metric thread type here. this part will run 100$ or so.

One 1/2" ball valve - McMaster Carr
**I had originally used a hydraulic line check valve here so that there would be no possible way to accidentally turn both ball valves and cut off the flow of coolant completely - the check valve didnt crack under 5 PSI, however, which caused issues on this. I had to settle for this second ball valve for unimpeded flow and locked it open with a band clamp. In emergency failure of the heat exchange circuit I can shut it off.***

several 1/2" brass close nipples and elbows to fit these parts together- you can cut many of these out using street nipples.

About 10 1/2" barbed to 1/2" NPT fittings - McMaster Carr

One water pump - TEEL brand - though any RV type will work- look for the "on demand" types that shut off when you close the shower head valve. Mine was a free spare in the garage. for ease of use, find one with the 3/4" garden hose male with female threads inside both fittings.

about 30' of 10AWG wire red and black

a switch rated over 15 Amps

In line fuse

two 1/2" barbed to female garden hose fittings

:victory: