Hot shower using exhaust heat exchanger

[4wdCamper]

Has anyone built a heat exchanger that uses the tailpipe gases to heat water for a shower?
I'm considering the tailpipe instead of tapping in the engine bay so htat the same heat exchanger can be moved to a power generator instead of the vehicle.
Any experience/advice with this is welcome.

 

[Joe917]

I would suggest something like the Isotherm Spa water heater. It uses the engine coolant or an electric element you can run off the generator.

 

[Regcabguy]

Consider a 2 gal garden sprayer. Replace the hose with a longer one from O'Reilly's. Shorten the sprayer a tad and splice in some more tubing to fit. Heat some water in your coffee pot and mix with cool to touch. Pump it up and you've got a nice shower using one gallon per person. The spray nozzle atomizes the water to your taste.
I reckon you'd have maybe $40 in it. I assembled one 25 yrs ago for Baja trips and I'm on the same unit.

 

[bigskypylot]

Consider a 2 gal garden sprayer. Replace the hose with a longer one from O'Reilly's. Shorten the sprayer a tad and splice in some more tubing to fit. Heat some water in your coffee pot and mix with cool to touch. Pump it up and you've got a nice shower using one gallon per person. The spray nozzle atomizes the water to your taste.
I reckon you'd have maybe $40 in it. I assembled one 25 yrs ago for Baja trips and I'm on the same unit.

Just saw something advertised on the "Road Shower" any opinions on those?

 

[pugslyyy]

I've looked at doing a liquid/liquid heat exchanger with the engine coolant before. There's no thermodynamic reason why a gas/liquid heat exchanger won't work, but it may place an unacceptable amount of backpressure on the exhaust system. As Verkstad points out liquid/liquid is far more efficient.

When I was in the Army we made hot water by hanging 5 gallon water cans in front of the exhaust from our gensets. It worked, but it took several hours to heat the water - but we worked 12 on / 12 off so after 12 hours the water was plenty warm enough for a nice shower.

 

[thebigblue]

The EGR return pipe going to the water-cooled intercooler in my G400 is also water-cooled, it´s not that big at all. But then again im`not sure how mush water temp changes ....

 

[Coachgeo]

Exhaust manifold wrap with copper tube. Old school method. Truck might get too hot for shower that way but a gen set maybe not so. Could always add a little reservoir and then run coolant thru the whatever tube you wrap the exhaust with and then run a coolant thru that with a heat exchanger to the shower water. That would be a way to stabalize the temp.

PS- 2 and 3cyl engined commercial Carpet cleaners in back of vans I believe use exhaust heat exchangers. Check some out for ideas. If Im right then there would be parts floating around out there already designed for this.

 

[Rickbfried]

Sounds way too complex. Look in the marine / boating world, using cooling system is SOP.

 

[Michael1929]

I'm building a a shower setup using 2 8'x6" diameter black pvc pipes to run up top on my rack. They will both have a fill spot and a tire valve in order to pressurize them. Being black they will retain heat but if worse comes to fruition I'll run some copper line down to the catillitic converter wrap it around and cycle the water with a small pump.

 

[I play outside]

Look into a flat plate heat exchanger. Compact, thermally efficient. Run it off one of the heater lines goin to the cab. Wrapping exhaust w copper sounds like a cumbersome eyesore. Just my 2c

 

[patoz]

Vehicle Shower Heat Exchanger




Back in the '80s when I was big into off-road 4x4 truck camping, I took a marine heat exchanger and mounted it under the hood in line with my vehicle heater hose, with the radiator water flowing through the larger tubes. The exchanger is about 12” long and 2.5” in diameter. Then, I plumbed the smaller tubes to the rear of the vehicle and connected one side to a 12VDC SureFlow 4.2gpm pump with the pressure demand electric valve. This became the intake side of the system. The other side became the discharge side and was connected to a handheld shower sprayer with an on-off valve. With this setup, the pump only pumps cold water and not extremely hot water, which may damage the pump itself.

When you wanted to take a hot shower (and I do mean HOT), you just dropped an intake hose into a bucket of water, stream, river, etc. and cranked up the truck. In a few minutes when the engine warmed up, the water flowing through the exchanger from the pump would be plenty hot to shower with even in the winter time. With the older vehicles, we found you could change the water temperature somewhat by turning the vehicle heater on, and using the temperature slide control, which would determine how much radiator water flowed through the heat exchanger.

Eventually, we found the best way to get and set the water temperature was to use a 6 gal plastic water can full of water, and keep recirculating the water through the system and back into the can until you reached the temperature you wanted. This usually only took about five minutes, and never damaged the pump. Then shut the engine off and pump out of the can to take your shower.

In order to connect my suction and discharge hoses, I built a nice looking control panel out of some angled aluminum and mounted it under my rear bumper next to the receiver hitch. The panel had a power switch and pilot light for the pump, and hot and cold 'quick connect fittings' using 3/8" pressure washer fittings. I also had a ‘Master Switch’ mounted under the dash so I could kill power going to it, so people couldn’t walk by in a parking lot and flip the switch just to see what it did and burn the pump up.

We would be camping on a sandbar on a river and freak out the canoe and kayakers when they would float by and see us taking a leisurely shower or washing our trucks off with an endless water supply.

 

[Borrego60]

Look into Helton heat exchangers. Very effective.http://www.expeditionportal.com/forum/threads/63643-03-Tundra-helton-heater-install