On Board Hot Water Shower System

[rayra]

How about a holding tank with a circulation pump that cycles the content thru a plate heat exchanger and simply has a thermo sensor on the pump circuit such that you switch the system on and it circulates the water while you are driving and auto-cuts the circulation pump when the set temperature is met. No mixing, no dual tanks, no excess plumbing. And the thermo will cut the pump back on if the tank temp drops before you are parked.

I really like that idea to use the rear heater circuit too, plumbing wise. BUT that means you'll be heating the rear of the vehicle. There usually isn't an 'off' on the rear fan system.

Positioning the tank just so and it would be like a hot water bottle for your sleeping arrangements, in winter.

 

[Bozman1]

I'll have to check my hoses I used but I'm pretty sure I used 1/2 for all the hoses but the output I used a smaller hose because I didn't want a heavy shower hose with shower head.
I put my pump before the heat exchanger. Pump can push or pull it doesn't matter from my use. Pump can run dry as well. I probably have at least 10 feet of hose each way on the pump. It has to pull water from 10 feet away. Push it into a heat exchanger and back to where it came from 10 away. Than probably another 5 feet of shower hose.
Both my input and output is in the rear of my bumper. The pump and heat exchanger is under the hood.


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Well it looks like I'll be returning all of my fittings and jumping to 1/2 inch. If you could double check sometime that would be awesome. I am hoping this also fixes the lower pressure issue when running through the exchanger. When I pull straight from the cold it does alright. The surflo pump specifically states 1/2 inch only as smaller line will actually make flow worse.. I guess I don't care enough to know why only to know that its true haha.

Sounds good with the amount of hose before and after. Now I don't need to worry about rerouting too much. Appreciate the info! And glad you got back quick. I was worried since this thread hasn't been active too recently.

 

[toyotech]

Well it looks like I'll be returning all of my fittings and jumping to 1/2 inch. If you could double check sometime that would be awesome. I am hoping this also fixes the lower pressure issue when running through the exchanger. When I pull straight from the cold it does alright. The surflo pump specifically states 1/2 inch only as smaller line will actually make flow worse.. I guess I don't care enough to know why only to know that its true haha.

Sounds good with the amount of hose before and after. Now I don't need to worry about rerouting too much. Appreciate the info! And glad you got back quick. I was worried since this thread hasn't been active too recently.

Here is the main parts list for my OBS
I still have little parts to order for the shower part and bumper attachment.
I will list the rest once I have I figured out. The rest is actually the quick disconnects I plan to add to the rear bumpers for input and output from pump.

Let's just say the brass quick disconnects was not cheap. I wanna say they are mainly for hydraulic use.

The pump recommends using 1/2 hose. The heater hose on the tundra are 5/8. It's actually bigger but 5/8 is the closest size and fits well.

I installed the heat exchanger after the factory heater valve (allows you to adjust temperature via inside the cab via air heat temp knob) inline with the factory heater core. Your factory air heater will still work as normal when shower isn't in use.
I will explain how I did my hose plumbing but you can do yours differently.
Water jug sits on swing out. Hose goes into the jug and runs to the engine where pump is located. The pump sucks water in from jug to water strainer than pushing water into heat exchanger (important that you push water into heat exchanger and not pull water thru heat exchanger so you don't run extremely hot water into pump) and back out to the to the rear of vehicle where I can plug my shower hose and take a shower. Now with a 10 plate heat exchanger. One pass does get water to whatever temp you set the heater control too. Goal is to get to camp, idle engine and hook up two hoses to water jug and recirculate for 5-10 mins depending on desired temp. This way I can shower with warm water and not have an idling engine. My solar set up should keep battery charged while running pump.

Depending on how you want your fittings. I went with barb. I didn't want to mess with threaded pipes and finding correct fittings.

Amazon

SHURFLO 4008-101-E65 3.0 revolution water pump
SHURFLO 255-313-Twist-Pipe-Strainer
SHURFLO 244-3926 elbow adaptor

1/2x50 black heater hose
5/8x1 black heater hose

(2 sets) Precision Brand M6S Micro Seal, Miniature All Stainless Worm Gear Hose Clamp, 5/16" - 7/8" (Pack of 10)

Hilon PVC Reinforced Hose 3/8" ID X 5/8 " OD 25 FT

Delta Faucet 52650-PK Universal Showering Components, 2-Setting Showerhead, Chrome


http://www.dudadiesel.com/heat_exchangers.php

B3-12A 10 Plate Heat Exchanger with M5-.08 Mounting Studs (1/2 barb)


Home Depot

(2) watts brass hose barb (LFA 493) 5/8 in ID x 1/2 in MIP
(2) watts brass hose barb (LFA 390) 1/2 in ID x 1/2 in FIP

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[rayra]

A caution on the use of QD connectors for your fluid plumbing, as their male fittings basically neck your line down to 1/4" ID. That matters much more with incompressible fluids than it does with air.
A 1/4" ID line has much less cross section / flow capacity of a 1/2" ID line, at the same pressures. Mathmatically it's 1/4 the area. But plumbing references say the flow is 1/3 as much.
So using a QD coupling creates quite a restriction for fluid flows. It may not matter much in some applications, but it would seem to be an issue in an application such as this, IMAO.

 

[toyotech]

A caution on the use of QD connectors for your fluid plumbing, as their male fittings basically neck your line down to 1/4" ID. That matters much more with incompressible fluids than it does with air.
A 1/4" ID line has much less cross section / flow capacity of a 1/2" ID line, at the same pressures. Mathmatically it's 1/4 the area. But plumbing references say the flow is 1/3 as much.
So using a QD coupling creates quite a restriction for fluid flows. It may not matter much in some applications, but it would seem to be an issue in an application such as this, IMAO.

I'm not using standard air fittings for my water. Left in picture is my OBA. Right is OBS which I'm using high end hydraulic QD. I haven't noticed any performance issues. Besides when you get down to it. The shower is the most restricted since you are not taking a Hollywood shower with unlimited supply of water. My shower head flows very little. Forgot the GPH specs. But it's stupid low.


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[inv3ctiv3]

This might not be the best place for this but this is my On board water system and it works great, it's not heated but can take water from any source (so you can boil water and use that if you like) and cost me like $100 in parts and a couple of hours of my time to install.....

 

[F350joe]

I had almost the same system as the OP in my old van and I putting together the same system in my truck now. It worked great even if not using the heater aspect.

A couple notes to keep in mind would be to.

1. Plan on using 90 degree fittings coming out of the bottom of the eco temp if space is limited.
2. Portable 7 gal water jugs make for a nice long camp shower, many times it is easier to refill the tank with the jug or just run off the jug.
3. Get the biggest pump the heater can handle, you will want the power for dishes.
4. The wind will blow out the heater flame if exposed, plan on it, and it sucks.

 

[macjack]

So after a few years of using the eccotemp L5 in my previous post, I would say yes the 90 degree fittings make a huge difference for fit, and overall the system works very well, and can operate at altitudes of 9k. I don't think I got super efficient combustion at that elevation, but I had hot water. Instantly, without starting the van. Also, the cabinet protects against wind, and there just aren't any more dangers in my experience than a propane powered heater like a propex or a propane stove burner, used in a cabinet or the enclosed space of a van. I did add a 2inch hole at the bottom of the cabinet and made both my fans "out" fans, so that I am pulling air in from the bottom up and out, and if there ever is a leak while it is in the cabinet, there is an out path for the propane to follow before the eccotemp fires up. And it is only possible to run the unit with the rear hatch open.
I have also run a line back up to the sink, so I can use hot water for dishwashing. Between that and the curtain around the rear hatch for showering, my wife is happy, too.


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[Haraald]

Eccotemps explode:

https://www.youtube.com/watch?v=EyByP4Nf4HE
http://www.justrightbus.com/2014/06/EccotempReview.html

I guess make sure to encase it in blasting mats? Their customer service won't respond

 

[macjack]

http://www.justrightbus.com/2014/06/EccotempReview.html

I guess make sure to encase it in blasting mats? Their customer service won't respond

Well that doesn't seem great.
I'm trying to understand what happened and the factors of justrightbus's situation. That was essentially a home use situation in a tiny house. It was outside all the time.
While I think "explode" and "blast" are a bit dramatic, they are not too far from what happened . Of course the repeating YouTube video of a burning house from Haraald is a point taken about what we don't want to happen, but there is no evidence that something like that has actually happened.
Here's the picture from justrightbus:

I'm not trying to minimize the risk, just trying to figure out the base rate of failure and the actual stakes should it go wrong.
I imagine that many people might not be comfortable with anything above zero base rate, and some wouldn't mount propane to their vehicles at all. On the other hand, there are lots of propane burners, propane heaters, and even propane instant hot water heaters.
For me, I read in their story that they heard a "screee-poof" sound several times for a few months before the larger poof happened. In this instance, the one documented instance of a flameout, there was a signal before it happened, and this signal happened for a while. Also, they ran their unit as a primary hot water for their living situation. I am using it for about ten to twenty showers a year. I imagine that elevation may come in to play, as incomplete combustion over time could cause soot buildup requiring cleaning, like a backpacking stove. Lastly, I am thinking that a controlled environment like a vented cabinet may well provide a more consistent environment than one out in wind and rain.
I'll have to think more about this over time, and maybe get another fire extinguisher for the back cabinet mount. But my experience so far is nothing like those full timers.
Everyone will make their own choices based on risk and reward. I'm not quite to the point of assuming that any eccotemp will end up like that scary video.


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[Haraald]

I'm not trying to minimize the risk, just trying to figure out the base rate of failure and the actual stakes should it go wrong.

I've made the decision to drape a couple layers of rubber mats around mine to protect against shrapnel. Blasting mats are made out of tires so I assume that's the best material?

Also, everyone should note that Eccotemp's manual for L5 & L10 says not to install on a vehicle or any place subject to vibration; so we're all taking a risk here.

 

[jeegro]

What is the right way to mount fittings to a panel? I've searched and searched for barbed to QD "bulkhead" fittings, barbed to NPT thread, etc etc. Is the right way to just use 1/2" NPT female to 1/2" NPT male bulkhead fittings like these: https://www.mcmaster.com/#standard-metal-through-wall-couplings/=18gkevy and then put your barb on the rear, and QD on the outside?

And what about panel mounted ball valves? I can't find any.

Basically I'm wanting to make a panel that has water fill port (w/ screen), ball valve to bypass heat exchanger, QD outlet, spigot outlet w/ valve, and ideally a water input QD (for sourcing from river, lake, etc. Mounted flush to the rear driver quarter panel.

 

[jeegro]

That makes sense, not sure if I am overthinking it, the only thing I was really thinking of adding that I don't see mentioned here are those bulkhead fittings. Here's a diagram of my plan


I'm going to add the heat exchanger later.

I could probably hide the ball valve (source selector) along the frame rail. As for the fill port, QD input, QD output, and spigot, I see your point about protruding fittings. I could maybe make something recessed... but not sure my skills are up to it.

I'm installing an onboard air system at the same time, which involves a regulator, dual needle gauge, and QD fitting that I wanted to put on the same panel as the water.

I'm just a little hung up on the fittings and how to mount them properly.

 

[Haraald]

I dont think failure on these things are brisant. I say use flame resistant such as rockwool or welding blanket. :ylsmoke: Fwiw. Curious, I opened mine up just to see if any sort of QA problems maybe of a 100$ gas appliance. Simple & clean design, but the thing is a bit lightweight & could benefit minor ruggedising were one feeling ambitious.

I followed your advice and draped a couple layers of welding blanket all around a Eccotemp L10 I bought, mounted it in a Stowaway2 hitchbox. I put a little 3" marine duct fan next to it to cool it down a bit, hopefully it won't blow the ignition out. My little propane tank is right on the other side of the welding blanket, which kinda makes me nervous, but oh well.

I have a Shurflo 3 gpm pump and tested it and it worked very well with good pressure, glad I didn't get the L5. I'll keep everyone updated.

 

[jeegro]

Something like this could work to recess the fittings in the vehicle body? http://www.moyermarine.com/cgi-bin/shopper.cgi?preadd=action&key=GAUG_16_556