Onboard shower install questions...

[FJ40_owner]

Firts of all some of what I write is tongue in cheek. I like to razz some folks... Its all good my brother.

Based on my installation using the parts that I have, that is an Edlebrock heatx, a 12 volt pump and 65 degree water my Heatx would need to run for a long long long time to heat water up to say 85 from 65. Perhaps long enough to burn 2 gallons of fuel, who knows exactly. Trail fuel for me is a precious commodity I am unwilling to waste when I am perfectly able to jump in a creek or stream. My .02.

Now I love home brewing stuff and plan to build my own HX for a domestic HW install and the drill that the OP is engaged in is a fine undertaking. I was only teasing a little, questioning the application, offering the results of my experiments and an alternate solution.

Stay clean and best regards to everyone.

BigJim

Originally Posted by pismojim

Come on Big Jim, redundant, off-topic and not true.

The engine is already hot at the end of a dusty day of wheeling and there is no way I burn 2 gallons of gas idling my motor for shower.

This is a fun project and a fun mod for *most* anyone.

[Trollhole]

Originally Posted by CaliCruiser

This weekend I am going to install a heat exchanger and pump for an onboard shower, and I am looking for opinions on a few thing. First of all, here is a shot of the materials I have right now, I figure I will make about ten trips to store tomorrow for supplys. . . This is going on my fj60, so if anyone has pics of their own install that would be cool to.







(1) What kind of hose should I use for the the hot water side of the heat exchanger that will go to the shower head? I used Heater hose and cpvc but my system is a little different, most I have seen use a cheap garden hose.
What is a good length for the pickup side of the pump? My flowjet is 3.5 gpm I've run up to 150ft with no issues using cheap garden hose. Rise is the biggest issue. The higher the rise to the pump (vertical distance from water to pump) the less water output you will have.

(2) Should I just put a switch in the engine compartment to activate the pump? You have a auto pressure switch on your pump so when pressure drops it will cut on when it gets over like 80psi it will cut off. If you have a leak anywhere after the pump to the showerhead it will cycle on and off wich is not good long term so seal your leaks. You need a switch though and make sure you use a relay. MIne is in the cab and has a light when it is on.

(3) Is it best to interupt a hose after the heater core to be able to somewhat control the temp or is it going to limit my flow? Don't worry about regulating the flow to the heat exchanger. Your gonna want it wide open all the time. You will regulate heat by varying output from the showerhead. With a 2.5 -3.5 gpm pump a heat exchanger like the one you have is gonna struggle to put out 100 degree water at full flow. Unless your crazy and willing to run your 2f at around 3 or 4k with no load. Make sure you connect the heat exchanger before you go into the heater core.

Here is a shot of the pump Flowjet is a good pump. Not sure on the model and the flow.




Here is a shot of the heat exchanger No idea of model but looks like a boat heat exchanger or similar. Coolant goes in the end. If it has a coil that runs in a loop front to back front to back it will not matter which end of the heat exchanger you attach the input and the output to for the fresh water. If it infact has aspiraled coil going from one end to the other or where flow is all in one direction you want to have your input opposite the inlet of the coolant. This allows better heat transfer.

See red

[Trollhole]

This is the inside of a homemade unit.



Pros. Cheap to make

Cons. Low water volume
Poor heat transfer due to water moving from the hottest part of the coolant to the coolest and back again.



This is a plate heat exchanger.

Pros. great heat exchange
High flow

Cons. more expensive due to need for extra fittings and takes some creativity to mount.


The one below is how most exchangers work.

Pros good waterflow
good heat exchange
Very economical

Cons. not as easy to make

[Trollhole]

Originally Posted by FJ40_owner

Firts of all some of what I write is tongue in cheek. I like to razz some folks... Its all good my brother.

Based on my installation using the parts that I have, that is an Edlebrock heatx, a 12 volt pump and 65 degree water my Heatx would need to run for a long long long time to heat water up to say 85 from 65. Perhaps long enough to burn 2 gallons of fuel, who knows exactly. Trail fuel for me is a precious commodity I am unwilling to waste when I am perfectly able to jump in a creek or stream. My .02.

Now I love home brewing stuff and plan to build my own HX for a domestic HW install and the drill that the OP is engaged in is a fine undertaking. I was only teasing a little, questioning the application, offering the results of my experiments and an alternate solution.

Stay clean and best regards to everyone.

BigJim

Good stuff. You got me razzed. Carrying around a buch of propane, a heat unit that will get bounced around on the trail and low flow and having to wait for a shower for every person who is gonna use it. And then tell them to go fill the bucket and then wait 5-10 min for luke warm water that spits out on you all the while you are looking in the bucket to see if your gonna run out. And I hope everyone is not gonna need to haul one around and you will have fuel for everyone. Tellico this summer was hot and the campsite was dry except for a tiny stream that was about 150ft away in the woods. It took about 5 min to hook it up and have hot water as long as there was gas in the tank. A nice long shower for 15 of your friends with 3.5gpm and 100 degrees is priceless.

[CaliCruiser]

Wow guys, I missed quite a bit. Thanks for the additional info Marshall. I haven't had a chance to work on it yet, I should have some experimental data next week. Finals week sucks. . .

[Mace]

okay, the problem with running the shower water through the end caps is that you do not have nearly enough residence time for the water to heat up. the problem with running the water through the outer section is that the small inner tubes will cool very quickly. The design I have actually uses a copper coil in side a 2" outer sheath.. The coil has the shower water in it. The 2" has radiator fluid in it. Increase the flow as much as possible in the radiator portion so heat is uniform. It is directional as well. You want the intake for the showerr water to go in near the output for the coolant.. That way you are slowly heating the shower water against the flow of coolant instead of with the flow of coolant.. This increases the contact time of the "hot" coolant with the "cold" shower water.


Another option is to wrap copper tubing around the exhaust pipe.. That works freaking awesome..

[will.the.thrill]

as far as wrapping copper tube around the exhaust pipe, has anyone does this? how long is the winding and what kind of outlet temp results from that?

i know those compact HX work very well from reading other posts....but i have much more scr4p (it censored me!!) linesets than i do money to spend on a plate exchanger...

[CaliCruiser]

I'm going to get something done in the next couple of days I hope. . .

[CaliCruiser]

Heat xchanger has a home under the hood! It heats the water excellent at about 1300 rpm's and above, so I must have not gotten enough flow before. I still need to find a permanent mount for the 12 volt pump, but the testing phase is over! More pics soon. . .

Dylan

[Cruiserdrew]

Dylan---Congrats. I may hit you up for a shower this summer! Way to stay on it.

[alia176]

Originally Posted by will.the.thrill

as far as wrapping copper tube around the exhaust pipe, has anyone does this? how long is the winding and what kind of outlet temp results from that?

I did this on previous vehicles for the windshield washer fluid. It heated up the water just enough to do some good on a cold, nasty winshield. Maybe just one wrap or two was all that was needed. In order to heat up water for showering, I'm imagining lots of wraps and somewhat slower water flow.

[450 DUDE]

YO Big D:

I have this heat exchanger laying around if you need to upgrade.?

ken

[Trollhole]

lol

[CaliCruiser]

I guess I never finished the thread, huh? It is working fine, but if I need an upgrade, I'll swing by Ken.

Dylan

[2ndGenToyotaFan]

Dylan has a shower....... (mental note) I thought your 60 was as cool as it could get? I guess I was wrong!