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

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Permalink Reply by RJAMSOIL on March 18, 2012 at 8:42pm

Awesome meeting everyone and seeing some old faces, showers were cool and it was great to hang out!

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Permalink Reply by Dave Crockett on March 18, 2012 at 10:15pm

Okay, since you guys made the event today,which I wish I could have, but had previous plans. Which is the hottest line to tap into for the hot water exchanger? I have a heat exchanger that I made and then bought a 30 plate exchanger, and can't get anything except for cold water from either. Any ideas? Thanx.

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Permalink Reply by paraextreme on March 18, 2012 at 10:46pm

You should get heat from any of the heater hoses.try the in cab heat control to high and fan off.if you already did that then try playing with the RPMS.if that doesn't help i would think it would be the heat exchanger not working.you have pics of the one you made?hope that helps

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Permalink Reply by Overlander36 on March 18, 2012 at 10:47pm

Dave, it looked like all the systems were tapped into the lower hose coming through the firewall. Not sure if that is the return or supply line to the heater. I understand it is best to have the water and the coolant circulating in opposite directions through the plate exchanger. Also I believe the heater control must be turned to high inside the truck.

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Permalink Reply by Dave Crockett on March 31, 2012 at 9:44pm

Hi Jens, I finally did it. I have a hot water system that works beyond great. Lots of trys, but, done. I have to run my shower hoses yet. I have my shower rack in place, so, now, running the lines to the back of the truck and add the quick disconnects and then I'm done, finally. It's kinda big and not too pretty, but......How are you doing on yours. I have that full set-up with the 30 plate exchanger with a really nice mounting bracket for the FJ if you can figure out how to make it supply hot water. This one looks amazing. Let me know. 318-6690.

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Permalink Reply by paraextreme on April 1, 2012 at 12:45am

Post pics

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Permalink Reply by manoweb on March 19, 2012 at 8:12am

What is the advised coolant fluid for the FJ engine? I need to top off mine. Maybe it has something to do with the poor performance I measured yesterday.

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Permalink Reply by paraextreme on March 19, 2012 at 9:40am

Hi manoweb i don't think it was the coolant if it was way to low your FJ would over heat.I just use prestone pre mix.it says it is it mixes with any fluid for any auto maker.

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Permalink Reply by The Josh on March 25, 2012 at 9:04pm

a update to my shower system

got a lot of stuff done with the On Board Water System this weekend

Welding up some mounts (thanks to my buddy eric for the fab work)

[IMG]http://i79.photobucket.com/albums/j124/chevelle02/Wheelin/042f7e25.jpg[/IMG]

crossmembers boxed, grinded down and mocked up

[IMG]http://i79.photobucket.com/albums/j124/chevelle02/Wheelin/917e5922.jpg[/IMG]

then i primed and painted the mounts and cross members. i reinstalled the air tank and moved a few fittings around. i wrapped the top and bottom of the water tank in some B-quiet just to assist with vibration and retaining heat (used the last i had left) for padding on the top of the tank i used a 1/2 high density insulfoam liner and ill do the same on the bottom under the mounts when i do final installation (still want to drive around a bit and see how it holds up

[IMG]http://i79.photobucket.com/albums/j124/chevelle02/Wheelin/ddb36af4.jpg[/IMG]

[IMG]http://i79.photobucket.com/albums/j124/chevelle02/Wheelin/fcd891a3.jpg[/IMG]

[IMG]http://i79.photobucket.com/albums/j124/chevelle02/Wheelin/9605e09a.jpg[/IMG]

i still need to install the pump and wire that up. i was originally planning on just running 1 pump that would pump the water to the heat exchanger and the bank into the tank then i can switch it to run to the shower. but after many time thinking about it i may end up running 2 pumps, 1 for the heat exchanger and 1 soley for the shower, it'll actually simplify the system where ill be able to control the system from inside the cargo area versus manually switching a valve underneath the truck.

i plan to have the pump switches inside the cargo area with the water temp meter above it, installed on the little access panel on the left.

also installed the fresh water fill valve into the bumper. came out very clean!

[IMG]http://i79.photobucket.com/albums/j124/chevelle02/Wheelin/2f71a701.jpg[/IMG]