Camp shower water heater.

Any of you ever try using a plate style heat exchanger to heat shower water with engine coolant?? It seems as though it would work well by T-ing off of the heater hoses, but would it cause any problems with coolant flow? I wouldn't think so. If anything, seems like it might cause the truck to run cooler.

 

Since there's a T-stat, it wouldn't run cooler, it would just take longer for the t-stat to open.

That adds another point of failure to your coolant system = no bueno, IMO...

 

Unless there are valves before the heat exchangers, or disconnects, or some other method of making the heat exchanger only flow when you want to use it. As far as the point of failure, I'm not too worried about that. Hoses are pretty reliable as long as they're monitored. And I carry coolant when I'm off-road anyways.

 

I carry coolant, too. That's a pretty normal thing regardless.

I'm just generally not a fan of involving critical engine components in a "luxury" item. There's also all the added plumbing associated with the shower system itself. If any of those components fail, it wouldn't leave you stranded, but you wouldn't have your hot showers, either. You'd have all this stuff and no shower unless you have some backup system - might as well just carry the backup system.

Perhaps using the exhaust instead? Temps are obviously higher and not as consistent, so you'd still need a way to control the water temp. Maybe use some copper tubing wrapped around behind the muffler (cooler than the headers) and a t-stat in your holding tank that turns on a pump when the temp drops below a certain range, or opens a valve to divert the heated water. I could see perhaps not wanting to let the water sit in the heat exchanger coils and get super heated.

I just use one of those black bags with a hose on it. Set it in the sun for a couple hours and bam, hot water.

Those black ABS pipes people mount on their bed racks are pretty cool, too. You can even pressurize them with a bike pump or air compressor. You can't get much simpler.

 

I like these Zodi extreme shower:
http://zodi.com/hot-showers/extreme-shower.

You can fill it up with water, heat it up on a propane stove, once it's heated up to the desired temperature, have a nice hot shower. It only holds 2 gallons of water though.

I was looking at The Road Shower that mounts on a roof rack: https://roadshower.com/

The 10 gallon version would be nice and can be pressurized for showers/washing dishes/cleaning equipment. There's a temperature gauge on the side of the Road Shower that shows water temperature and will heat up the water on a sunny day or heated water can be added to the tank and be pressurized for a shower.

 

Between that heater, and the roadshower, you're at like $550 for a shower. I did some testing with a heat exchanger over last weekend and it worked great, and I'll have unlimited hot showers for like $100. I'm sure those things work great and all, but I'd rather spend my money on other things. But thanks for the input.

 

Yeah, I have been researching this very extensively. I have two heat exchangers here, both flat plate and swimming pool/hot tub type, and a couple of friends that have engineering degrees from Texas A@M what do the math for me. I am finding that the system suffers from too slow of flow from the heater loop and too short of resident time in the exchanger. In other works, if you want much more than 1 gal/minute useable warm shower flow this isn't a good option. You will be lucky to heat the water to warm, and certainly not hot. I am use to 2.6 gal/minute at 142 degrees:


A little more to set up, but MUCH more utility: Your shower at home is 1.5gpm. This is 2.6gpm. Do you know how much steam 2.6gpm at 140 degrees will generate? More that any steam bath I have been in. VERY therapeutic after a hard day on the water fishing. ALL NIGHT steam. I sit in there for about 45 minutes and it soaks the aches and pains away. You may just want a warm rinse. I want rejuvenation. They make two of these that are smaller. This one is overkill. THe small one is enough if you just want a hot shower.

 

Ran mine through the plate exchanger. 1 pass at 1.2gpm and the water is too hot to shower in. Not sure what numbers they were crunching, but this is plenty hot for me.

 

Have any of you looked at one of the Zodi showers that's heated with propane? http://zodi.com/hot-showers/hot-tap-with-case

You can use a 5 gallon bucket, put the water pump in the bucket of water, and have an instant hot shower on demand.

 

Part of my motivation for this heating method is to have something self contained (mounted under the hood) and to not carry additional propane.

Looks like a nice unit, just not what I'm after.

 

Jeff, can you set up test to run 10-20 gallons through it and measure temp then? My results yielded sustained dropping water temps to shower temp fail after a few minutes. Apparently 57 degree water (roughly what we have around here in winter) augments the radiator system's ability to cool antifreeze. I was having to rev mine to 1500-2000 to generate enough heat to barely keep up. Summer water time here? Maybe. Problem is...I don't do summertime hot showers in 95 degree heat and 85% humidity, so I don't need a hot shower in the summertime. But I do need one the other three seasons. Hence, my need for a system that heats 57 degree water to 106. All. Night. Long.

 

When we're camping, I don't have a need for sustained hot water. Myself, the kids, and the lady all know we're camping, and you won't have the same degree of luxuries. Honestly, past experience shows our showers to use no more than a gallon of water per shower, per person. I'd have no need for 10-20 gallons of hot water. That would be like 1-2 weeks of showers for us. I may test it at some point just to satisfy curiosity. But at the moment, there's no need. And I don't have it permanently mounted yet.

 

I understand what you're trying to do. The only thing is if the plumbing has issues with your cooling system, it may not be easy to repair out in the field. There's a truck camper that I saw online that has hot water plumbing integrated with the truck's cooling system that had cooper pipes going to the bed of his truck that has his water reservoir. He had it plumbed to the rear of the truck bed with a faucet and made a shower attachment for it as well. The owner of the truck had the choice of hot or cold water on demand. I'm having a hard time finding the picture or website it was on, but I think you would like it and use it as an inspiration for your build.

 

I've thought about that, and i plan to have either disconnects, or shut offs, so that the heat exchanger is only part of the system when I want it to be.

It may work, or it may be a waste of time. But if it works, I think it'll be pretty awesome.

 

Ok, it took me awhile, but I found the truck that I saw before online. It was on the Expedition Portal website:

https://www.expeditionportal.com/forum/threads/latest-project-truck-drawers-sleeping-platform.47516/

I was considering building a sleeping platform with the water reservoir. It was one of the best examples that I've seen online for a home built sleeping platform.

 

Would love to see the exchanger mounting brackets you came up with Jeff. I haven't got that far.

 

Mine is mounted inline in the heater hose supply line. You vary the temperature by using the heater controls. It's got a pump in the engine bay and I have the inlet and outlet mounted on the front bumper. Using a bucket, or convenient lake, you hook up the supply line and toss it in, then hook up the outlet line with the shower head on it, run the pump for a bit to prime it and go to work. It can't quite keep up with running full-time, but since the showerhead had an on/off switch on it, there's more than enough hot water to take a "sailor shower". On-rinse, off-lather, on-rinse, off. Repeat. Gals with long hair complain about there not being enough, but if you aren't trying to wash 30 lbs of hair, there's plenty.

 

Thanks for that input. Depending on how complicated it gets, I'm considering using a thermostatic mixing valve, to prevent scalding. During the brief test I did, when you have the nozzle off, the water cooks in the heat exchanger, and comes out screamin' hot. Do you mind sharing the details of your pump/ heat exchanger?

Thanks!

 

Solar heating, pressurize with a foot pump. And it packs down to a fairly small size.

Nemo Helio Portable Pressure Shower with Foot Pump, Black/Sunset

https://www.amazon.com/dp/B075Y4WRL...olid=21COL68XZ25S3&psc=1&ref_=lv_ov_lig_dp_it

 

It's pretty straight forward, it's one of these that I mounted during the build:

https://www.hotcampshowers.com/vehicle_mounted_shower

I just noticed that I don't have anything about it on my site, but I will get some pics the next time I think about it.