Onboard shower install questions...

[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?
What is a good length for the pickup side of the pump?

(2) Should I just put a switch in the engine compartment to activate the pump?

(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?

Here is a shot of the pump



Here is a shot of the heat exchanger

[Cruiserdrew]

Originally Posted by CaliCruiser

(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?
What is a good length for the pickup side of the pump?

(2) Should I just put a switch in the engine compartment to activate the pump?

(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?

1) I don't think it a=matters that much. i would be comfortable using something robust like Green Stripe hose, but the nylon reinforced stuff should be fine with temps below 220F.

2) That would be easy. Fuse the wire to the battery, switch prior to the pump, good to go.

3)I would not interrupt the output, since by definition it limits the flow. I would run the input through the rear heater, and let the rear heater control control the temp. That way the pumps only job is to pump water through the heat exchanger.

Jim Brantley has the slickest set up for this-send him a PM. The "hot" input comes from the rear heater. That way flow through the rear heater controls the temp. The pump just pumps. He even has quick connects for the hoses right at the grill. Very slick set up, you should just copy it.

Nice mod.

[CaliCruiser]

Cool Andy, that is the type of stuff I'm looking for. I should have checked out Jims rig more down at SNT.

So you are saying run ---> inlet hose--->pump--->exchanger into a rear heater line---> to a shower head?

[Cruiserdrew]

Originally Posted by CaliCruiser

Cool Andy, that is the type of stuff I'm looking for. I should have checked out Jims rig more down at SNT.

So you are saying run ---> inlet hose--->pump--->exchanger into a rear heater line---> to a shower head?

You're up early!

On Jim's (and you should PM him for the real scoop), The rear heater is the hot coolant supply for the heat exchanger. The running motor is what circulates the coolant. So the electric pump only pumps through the exchanger, and the heat is supplied by the coolant coming out of the rear heater. If you turn the rear heat temp control down, then less coolant flows into the exchanger and the fresh water temp drops. It's very slick.

It went like this: Ouch, ouch ouch, turn the MF down....Aieeeeeee way tooo cold, Ahhhh just right. It's a two person operation.

Just to be clear, the fresh water only flows through the exchanger, and the coolant from the rear heater brings the heat.

edit:http://www.pirate4x4.com/forum/showt...1&page=2&pp=25 scroll down

[CaliCruiser]

Excellent! I might just change my mind and carry along a big ass hot tub to party in like those guys. . .

I better get crackin' now.

Dylan

[pismojim]

Dylan, it looks like you're well on your way!

Be sure to "crossflow" the hot coolant and the fresh water. That is the Hot Coolant IN on the same end as the fresh water OUT. (Maximizes the "delta" temps for maximum efficiency)

The white hose in your pic works OK and is easiest to carry because it's soft. It works OK for the outlet to the shower but you'll want "stiffer" garden hose for the suction side or it will collapse.

Instead of the sprinkler head I used one of those slow flow watering thingy that looks like a hand grenade. I think it might be less restrictive and less prone to clogging.

You may need to change shower heads too. Look for a smaller "low flow" head so you'll have a good spray with less flow rate. You'll also want some sort of valve to regulate flow. I use one of those cheap simple plastic hose valves. You can adjust the shower temp by regulating the flow rate. Less flow > hotter water, more flow > cooler water.

You'll have to remind people to always leave the water running, even after they are finished. Otherwise, when you open the valve back up you'll have 200 degeee water (ie; steam) Ouch!!

It's a great project, good luck!

P.S. expect to be invited on more wheeling trips when you have the shower! Get a chain saw too and you'll be very popular!

[450 DUDE]

Dude I did not know you showered.



Looking good , The only thing I have to add I would ditch the garden hose and fittings. maybe go with some barb fittings and better tubing @ the exchanger and some QD's mounted out side.
Some of those shower heads have a restrictor plate, you might want to drill it or toss it . The nice thing about the plate is you can drill larger holes until you get the flow you like.


ken

[FJ40_owner]

Pretty expensive way to make hot water with gas at $3.30+ per gallon.

Why not just jump in your water source and be done with it? Be a manly man.

I ripped the heat x out of my cruiser. Anyone want it?

Smile.

JB

[CaliCruiser]

I might take it off your hands.



Thanks for the tips guys, one last question. . .

On the rear heater lines I plan on tapping into the lines where they enter the engine compartment. Which one do I want to tap into, I can't figure which line goes into the rear heater and which one comes out of the rear heater.

Dylan

[spressomon]

The clear tubing that came with the HH went soft when the hot water was flowing...and then water line would get kinked cutting off flow right where the hose entered the shower enclosure window. So I ended up with a temp resistant hose that works much better but isn't as pliable. Try what you already have first...

My shower head (again from the HH kit) has an in-line on/off switch that ends up inside the shower enclosure so that I can turn it on & off to conserve water. Ditto on the shower head.

I also use my manual throttle control to dial in the temp...seems to work just fine at 1400 rpm . It'd be nice to have a remote ignition switch to shut the engine down when the shower is over when no one's around ...

I just installed a standard 12V cig style plug on the end of the pump and then wired in a 12v fused receptacle which I anchored with a custom little bracket...

[spressomon]

Originally Posted by CaliCruiser

I might take it off your hands.



Thanks for the tips guys, one last question. . .

On the rear heater lines I plan on tapping into the lines where they enter the engine compartment. Which one do I want to tap into, I can't figure which line goes into the rear heater and which one comes out of the rear heater.

Dylan

Dylan...when the motor is hot just touch each outlet hose...the hotter one will be your 'enter' side and the slightly cooler will be your 'exit' side from the heater core.

[CaliCruiser]

Thanks for all the tips guys. I should have it nearly finished tomorrow, I got side tracked several times today Heat xchanger is installed though. . .

[450 DUDE]

Looking good bro!

When can I bring my soap and towel over??

ken

[CaliCruiser]

Soon I hope!

I have a question for you guys. . .




Based on this picture of the xchanger, I want to run the cold water through the small tubes, and the hot coolant through the top ports to surround the small tubes correct? This would provide the best surface area contact to heat the water right? I started to plumb the system but a few buddies of mine and a few neighbors said it would never work. Let me know if I am crazy.

[450 DUDE]

I dont know if this helps but the X changers I work with use warm medium on the out side and product to be warmed up in the tubing inside , Thats how I would smoke that thing.

ken

[DBOZ40]

It looks like an old Sioux Indian "Peace Pipe" that Sitting Bull may have once smoked out of.

[CaliCruiser]

Anyone else?

[Cruiserdrew]

Originally Posted by CaliCruiser

Soon I hope!

I have a question for you guys. . .




Based on this picture of the xchanger, I want to run the cold water through the small tubes, and the hot coolant through the top ports to surround the small tubes correct? This would provide the best surface area contact to heat the water right? I started to plumb the system but a few buddies of mine and a few neighbors said it would never work. Let me know if I am crazy.

Correct-remember the counter current thing Jim was talking about and just let her rip. You'll find showers are nice, and you'll have an easier time with the chicks.

[CaliCruiser]

If I can get the damn thing to work! I spent about four hours messing around with this thing and I couldn't get anything above warm at extremely low volume. I tried every combination of inlet and oulet and direction with poor results each time. I don't have the pump wired up yet so I just ran the hose to the garden hose and used that as my temporary 'pump'. It seems to me like I am not getting enough coolant flow throught the xchanger to transfer heat. Of all the testing I would say that flooding the coolant in the chamber with the water running through the small diameter tubes worked the best at very low volume. Did I go with a bad design. . . ?


Dylan

[Cruiserdrew]

Originally Posted by CaliCruiser

If I can get the damn thing to work! I spent about four hours messing around with this thing and I couldn't get anything above warm at extremely low volume. I tried every combination of inlet and oulet and direction with poor results each time. I don't have the pump wired up yet so I just ran the hose to the garden hose and used that as my temporary 'pump'. It seems to me like I am not getting enough coolant flow throught the xchanger to transfer heat. Of all the testing I would say that flooding the coolant in the chamber with the water running through the small diameter tubes worked the best at very low volume. Did I go with a bad design. . . ?


Dylan

Your home brew looks great. Is your 60 fully hot when doing the test? With the low flow in the small pipes, it has the best chance to pick up the max heat, so keep the hot coolant around the pipes. You have to rev the 60 up to about 1800 rpm as well to increase the flow. You did remember to set the rear heat to full hot?

Remember too, the hose can supply way more GPM than your pump. It may simply be blasting cold water though the exchanger too fast. I think it's cool you made your own. If I were doing it, I'd get the same industrial exchanger that Jim had, but that's cheating. Keep going, you'll beat this one.

[CaliCruiser]

Could I have tapped into the wrong hardline coming up from the rear heater? I followed the rear hardlines up into the passenger side of the engine compartment right next to the starter. The one I chose is the closest to the engine, which is from what I can tell the outlet. I thought about the faucet putting out to much pressure as well maybe that has something to do with it. . . I'll put some more time into it this week. Highs in the upper 30's and leaks squirting in your face are not the most productive conditions unfortunetly. . .

Dylan

[akraven]

When I set up the shower on mine I tried a couple of differient style exchangers. The one like your's I never could get a good hot water flow through even though I had seen other people do it. I changed to a plate style that I bought on ebay and have had good luck with it. Here is one similar ro mine. http://cgi.ebay.com/30-Plate-Water-t...QQcmdZViewItem
The more plates the more heat that is exchanged. akraven

[cpg]

Originally Posted by CaliCruiser

Could I have tapped into the wrong harline coming up from the rear heater? I followed the rear hardlines up into the passenger side of the engine compartment right next to the starter. The one I chose is the closest to the engine, which is from what I can tell the outlet. I thought about the faucet putting out to much pressure as well maybe that has something to do with it. . . I'll put some more time into it this week. Highs in the upper 30's and leaks squirting in your face are not the most productive conditions unfortunetly. . .

Dylan

Try turning the hose to a lowest flow you can and still have a decent shower. Also try adjusting the idle rpm (mine works best at 1,100 rpm). If that does not work it may be that your heat exchanger is just to small.
Good luck

[LandCruiserPhil]

Test the temp on the outside of the exchanger it should close to the engine water temp. If it not you could be hook up wrong. Make sure you have the feed for the exchanger before the heater. By running on the outlet side of the heater you will have a temp loss from the heater core.

[pismojim]

Dylan, you haven't really told us much about your heat exchanger. It's capacity, rating, etc. They are not all the same. I tried to "design" a system using theory and --- hope you're sitting down --- math and physics. Theoretically, I could calculate everything up front and build the heat exchange myself using copper tubing.

Unfortunately, I was missing one important variable - the flow rate of the engine coolant through the heat exchange(HE). In other words, how many gpm of coolant going into the HE. The other variables, gpm of the fresh water (my 12VDC pump rating), the temp of the coolant, temp of the fresh water and even the coefficient for the copper and area of contact were all known. But I had no good way to get a flow rate for the coolant into the HE.

By the way, the area of contact is the critical part of the HE design. How much surface area separating the Hot and cold sides. The picture yhou provided doesn't really show me what's happening inside the HE.

Sadly, I'm lazy and have never got around to back calculating the coolant flow rate using the empirical data I've collected using my own shower. It shouldn't be hard, but I lost interest since the shower works great.

Sooooooo....

Dylan, pull the HE out of the truck and hook up your garden hose to one port. Run the hose at a constant flow rate into a bucket. Measure and time it and you'll have a gallons per minute (gpm). You might even try to set the hose at about the same flow as the 12VDC pump you picked up. Then switch the hose to another port and get a gpm from that port using the same "setting" on the hose. Are these flows the same or is one side more restrictive? I think you should plumb your coolant through the "least" restrictive side.

Installing into the FJ60....

I tapped into my coolant system -before- the rear heater. If you look at the firewall, there are two metal tubes coming up from the rear heater. I think the one on the right (looking from the front or the one towards the center of the rig if that makes more sense) is the supply and the one on the left is the return. So... tie into the coolant hose before the supply, between it and the engine. This goes to the "coolant in" on the HE, the "coolant out&