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 PBn'FJ on March 10, 2012 at 3:03pm

Are you referring to the ecotemp L5? Do you to provide your own 12v pump for the water?

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Permalink Reply by Ross Woody on March 11, 2012 at 3:22pm

Paul sells a kit that includes a small battery, hoses and a pump, but any rv pump will work.

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Permalink Reply by paraextreme on March 10, 2012 at 3:47pm

Thats strange that is one of the first places i called when i was looking for a R&M unit.the guy i talked to said that they were all out and unable to get a hold of the company that made them.that was about 2 years ago.i even asked and called the number he gave me with no luck.

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Permalink Reply by Ross Woody on March 11, 2012 at 3:33pm

Yes, RM went out of business, but Paul may have found an old stash. There have been some businesses that closed up, and they know Paul has the whole shower business.

There's an old thread with a bunch of ideas in it

http://offroadpassport.com/forum/showthread.php?t=754

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Permalink Reply by manoweb on March 10, 2012 at 3:55pm

I think that is exactly the place I have bought it from. The original website of R&M was

www.hotwatercampingshowerss.com but it does not seem to be working anymore. Once I was able to contact the guy using email rmspecpr AT cds1.net

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Permalink Reply by paraextreme on March 6, 2012 at 8:57pm

Well finally youtube processed my videos. I had to make 2 videos here are the links
https://www.youtube.com/watch?v=1D0fFLOJI7g&feature=youtube_gda...
https://www.youtube.com/watch?v=5gVfu25rNuI&feature=youtube_gda...

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Permalink Reply by Sonof40 on March 7, 2012 at 7:29am

Very nice work. How did you maintain the RPM?

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Permalink Reply by paraextreme on March 7, 2012 at 8:19am

Super high tech.1 liter coke bottle wedged on gas pedal. :) it works good and can adjust

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Permalink Reply by Sonof40 on March 7, 2012 at 8:30am

LOL

There's gotta be a way to do it electronically, I just haven't figured it out yet.

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Permalink Reply by manoweb on March 7, 2012 at 8:38am

No wait, why is that necessary? I had a look at the video but they are so long, I cannot watch them (at work). Why do you need to adjust RPM?

In my system I just let the engine idle, I set the temperature with the temperature setting in the dashboard. I should also try to stop the engine and see how hot it will stay, I guess it takes several minutes for the engine to cool enough for the shower to be unpleasant.

One of the problems I noticed on my system is that the bumper gets all "dirty" with soap and shampoo. Also, it's very advised to take a shower before sunset otherwise it can get cold when you shut-off the hot water; a good idea would be to have some sort of rubber mat to keep feet clean but then there is the problem of where to put this wet piece of rubber.