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

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Permalink Reply by paraextreme on March 11, 2012 at 10:10pm

Does anyone have a small scale that is going on the 18th.I would like to take the heat exchanger of the vehicles and weight them to get a comparison on how much copper is in each unit.

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Permalink Reply by manoweb on March 12, 2012 at 6:26am

I have a kitchen scale 1g precision 5kg max and a personal scale that is much less accurate but 130kg max...

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Permalink Reply by paraextreme on March 12, 2012 at 7:07am

Good morning manoweb the kitchen scale would probably work.The exchanger feels heavy but i dont think it is more then 11 LBS.I will try to get a gallon of premix anti freeze so we can top off the little that we loose in the process .