FJ Cruisers of Northern California

On Board Hot Shower

Well after many years of wanting to build my own OBHS heat exchanger i finally did.As i found out it was alot harder then i anticipated.After many designs in my head and on paper and after building 6 prototypes and testing.I setteled on one that i was really happy with.As i found out real soon copper is really expensive :( But the results are well worth it for me.The heat exchanger is made out of 2" copper tubbing and is 12" long and has 20' of tubbing inside the 2" tube.The water has to pass 3 times inside the 2" copper tube before it goes out to the shower head.That is only running the water thru the heat exchanger only once.I spliced the OBHS exchanger using the bottom hose coming out of the FJ heater.The OBHS exchanger heats supply water 59F up to 120F with the FJ at only 1500rpm.Still working on a flip up shower arm from my ARB bumper.Let me know what you guy's think

Attachments:

OBHS1.jpg, 1.2 MB
OBHS2.jpg, 775 KB

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Permalink Reply by DWH on March 3, 2012 at 9:34pm

Looks really nice. Post some installed shots as well.

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Permalink Reply by manoweb on March 3, 2012 at 9:47pm

Hi! That looks extremely similar to the one I have! I am interested in some sort of bracket actually. Even more, where to put a water tank or bag to easily make use of it. What I discovered is that it's best to take a shower in the afternoon when the Sun is still high: most of the day has passed so it's good to get clean, the car engine is already hot, and it's not too cold when you turn off the shower.

Here some pics of the install:

http://www.manoweb.com/alesan/temp/FJshower/

Please let's stay in touch and see if we can find a good solution for the bracket and the water supply

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Permalink Reply by paraextreme on March 4, 2012 at 10:51am

Hey manoweb yeah it looks like the R&M heat exchangers.I have only seen them on the web not sure what they used on the inside.Right now i have mine mounted in the same spot as you.I am using heater hose and zip ties to mount mine.at first i was thinking about having a tank mounted to have the water make another pass but after making this last prototype im really happy dont think i need one.i was going to make 3" tube 20" long and mount that on the frame rails.i will keep in touch and try to think of a mount.

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Permalink Reply by manoweb on March 5, 2012 at 8:18am

By the way, I am curious: why did you decide to build your own? The R&M is not cheap, but with about 350$ if I remember correctly you get everything, including hardware, the pump, and the install takes about half an hour (especially if you already know where to mount it). Reading your thread it seems you have put quite some time and money at this project. You just like to work on your project or you think the R&M is somewhat flawed?

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Permalink Reply by gringo on March 4, 2012 at 6:14am

did you make the heat exchanger yourself and do you plan on making any additional ones to sell? I would be interested if you did

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Permalink Reply by paraextreme on March 4, 2012 at 11:00am

Hi gringo yes i made the heat exchanger. At first i wasnt thinking about selling them.i just wanted the best heat exchanger for my rig after seeing that there was only a hand full of companies making them.i wasnt really happy with any of them so i started building to see what i could come up with.Right now i have 4 of them almost complete. It takes me almost 10 hours to make them with the process i have to use to get 20' of copper into the heat exchanger and then hand polishing.

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Permalink Reply by gringo on March 4, 2012 at 11:46am

I'll send you a pm to work something out

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Permalink Reply by Boss73 on March 4, 2012 at 8:24am

Thats very nice right there !

Oh and yes Coper is expensive. A couple of year ago we had people break into one of our buildings and see the copper wire cabling int he building from live high voltage panels inside the building. Crazy stuff !

I too will be interested in seeing the install finished product.

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Permalink Reply by Sonof40 on March 4, 2012 at 9:59am

Amazing that 20' is in there. I purchased a small exchanger from somewhere in Texas I think. Seems to work OK. What I usually do is recirculate the water for a few minutes, into the EXB 1 water can, to the desired temp. then I can kill the engine for peace.

Gringo, I found a way to attach the shower head to the awning. Works great.

Nice work para, you still flying planes?

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Permalink Reply by paraextreme on March 4, 2012 at 11:08am

Thanks sonof40 yeah 20' alot of work.I wish i was still flying planes the plane i took camping that time i lost flew it to high and lost radio control. Never did find the plane :( .thanks for kind words sonof40 means alot. I hope i can try getting out and go camping this year with you guys.my new job sucks can never get vacation approved for the dates.look forward to seeing you guys soon