On Board Water?

Totally, great idea. Billy at brute force has a sweet hot water system. He may or may not have called me naked in shop after trying out his shower.

 

Lol

 

There will be more resistance on the hot side of the split, but maybe that'll be equalized at the mixing valve? I'm debating putting another check valve on the cold side of the split for this purpose.
Here's the manifold I poorly illustrated earlier


I'm using the input side of the heater hose- may change it later though.

Stock heater hose will plug into port facing left, red hose will plug back into the supply port of the cab heater.

Bypass mode:
3 way valve will be turned so fluid flows from stock supply line, into the port facing left, be stopped by the check valve on bottom, and go through red hose back into truck.

Shower mode:
3 way valve turned to shut off bypass mode and force fluid to flow from supply line, through port facing left, through port facing camera in photo, in the "supply" port of heat exchange, out the "return" side, into that port on bottom, through the check valve and back into the red hose to return to vehicle.

This will make the whole system controlled by one turn of the handle, with no possible way to accidentally shut off the flow of coolant, and reducing failure points to only mechanical devices rated FAR higher than the stress this system could ever produce.

None yet, though I really need to rig something up. For now, I'll just be happy seeing this thing work in a sparklets jug of hose water!

 

Okay so like this then:

Water Source -> Pump -> T-Split (one to cold input on mixing valve, one to heat exchanger to become hot) From the heat exchanger to the mixing valve. Use the dial knob on mixing valve to adjust temperature as necessary.

Very simple, yes.

For the tank system, I can see why Josh put in two pumps into his design. Comparing my design to his, the extra pump eliminates the need of a plumbing three way ball valve, and arguably makes it more user friendly. Whatever I come up with needs to be idiot proof for my wife, and we have two small kids, so the thermostat takes care of any water that's too hot. Lots to ponder!

Spencer -- Looks good so far!

 

Crom. Same boat here. I was planning on 1 switch for ON, and 2 pumps originally. I have 4 children. Josh had the right idea. We just need to add to it

 

Yes you are correct with your plumbing routing.

Ditch the recirc pump/ball valve to make it idiot proof. One switch for shower on. Temperature adjusted with the dial on the thermo mixing valve. Done.

 

Thanks.

Since you've already done this, how about some questions? Which model thermo mixing valve do you recommend? What size fittings did it come with? There seems to be a wide variety in quality and specifications for these things. For example I've seen several Thermal mixing valve that had very low temperature ratings, so those are probably going to be avoided I suppose?

Also, on your install did employ some kind of reducer for going from the heater hose factory slice which is 5/8" to the plate heat exchanger? I can't tell from the photos that were posted in your thread what size fittings your plate heat exchanger used.

I'm thinking of tackling this project sooner than later so answering the questions is very helpful and I appreciate all your responses.

Happy Independence Day to everyone following this thread!

 

Maybe I can help I'm halfway through this project.

I used this
Powers Anti Scald Thermostatic Mixing Valve (Lead Free), 1/2" NPT Female LFLM495-1 by Powers

$155 Powers Under Counter Thermostatic Mixing Valve, 1/2 In. Union Npt Female, Rough Bronze, Lead Free

http://www.amazon.com/dp/B00JQIJ71K/ref=cm_sw_r_udp_awd_d0XTtb186K123

Powers anti scald valve with 1/2" female fittings.

As far as a reducer- I'm plumbing in a bypass using 5/8 to 1/2"NPT barbed fittings an back to 5/8" on the other side. I think I posted the pic of the finished manifold on this thread, maybe on my own.
From the manifold I have a 3 way valve & check valve with 1/2" barbed fittings going to & from the heat exchange. So there's your "reducer"
But I'd make sure there was a bypass with the largest fittings possible as to not impede your engine circulation during normal operation.

As far as the impact of all the resistance the heat exchanger loop will cause.... I'll find out soon!

Happy 4th & good luck!

 

This is the mixing valve I used. I got it from a local plumbing store here, Andrew Sheret, I seem to remember paying around $100. Remeber the 145degree rating is the max output temp, not the maximum rated input. Input temp should be 180 minimum (running temp of the taco)

The heat exchanger had 1/2" male threads on it, so all I needed to connect to the 5/8 heater hose was a 1/2 thread to 5/8 hose barb. I think I used a 90 off the heat exchanger threads, so it was a 1/2" male to 5/8" hose barb into that 90.

 

Thanks for the responses! I see the merit in the bypass now. I had not considered that until I pondered the step down from 5/8 to 1/2.

I may end up building in stages. Stage 1 for me may be a 10-plate heat exchanger and 12v pump with hoses utilizing the recirculation strategy and one of our existing three showers.

As a side note I had no idea how expensive a 3-way L-type stainless ball valve was! Cost more than the pump!

 

There is no actual signifigant "step down" 1/2" NPT female has an ID that is the same as the ID of the 5/8 hose barb. I know this makes no sense, and I dont fully understand the NPT sizing circus but;



This is a 1/2" NPT fitting.

Do whatever you guys want, but I am telling you, after 10's of thousands of miles on road and thousands of miles off, I have zero negative effects with my heater core with this setup. If you are so concerned about this, get a heat exchanger with 1" NPT fittings and a 50 plate heat exchanger!

I run no ball valve(s), the heat exchanger acts as an extra radiator while driving in normal conditions, and if my heat exchanger suddenly exploded for some unforeseen reason, I can return to a completely factory setup by undoing 2 hose clamps.

 

Excellent information, using a caliper tells the truth! Thank you for that.

I understand. You're experiece has value, no doubt about that. To be fair though, I think you're introducing an unknown element, extra wear and tear on the water pump, how much is unknown. Right? If my understanding is correct, wouldn't this be a lot like the skinny guy remarking, look at my body I'm healthy, yet he (and the water pump) is dying from hypertension? Maybe I'm over-thinking this, but that's why I think the bypass method has merit, it mitigates risk.

And just for the record I'm no expert here... Just trying to understand and mitigate risk.

Now about the heat exchangers, I was under the impression that the more plates introduce more resistance, is that not the case?

Duda Diesel has a few charts available about their heat exchangers. I studied the chart, and I understand it--I think. However, it seemed to imply there was a PSI reduction (penalty) for using a small 10 plate exchanger, where as the PSI reduction on a small 20 plate exchanger was less. Said another way, it required more force to pass fluid through a small plate exhcanger, than a equal sized exchanger with more plates.

Is that right?

Here is the graphic:

Lower right quadrant listed PSI reduction values I was concerned with


Graphic obtained while browsing this

$53 Duda Energy HX1210:HB12 B3-12A 10 Plate Stainless Steel Heat Exchanger with 1/2" Hose Barb Ports Copper Brazed, 1.2" Height, 2.9" Width, 7.5" Length

10-plate heat exchanger on Amazon

 

Spencer, Tweeek, what kind of hoses did you select? I know some used braided clear tubing, there is automotive heater hose? And there was talk about pex tubing.

Thanks again.

 

This is true, I do not know, and did not consider this angle, but commercial heat exchangers (ie helton) have been installed without bypasses for years with no ill effects, that I have read about, anyway. Your water pump is designed to move large amounts of water through your radiator, the volume it pumps for the heater core is small potatoes compared to the volume it moves through your engine and radiator. I doubt the small amount of additional travel the pump has to push the water through additional hoses and a high count plate exchanger will even make it break a sweat. That is just my opinion though.

That being said, the ballvalve will work, by all means use if it gives you peace of mind, that is a good thing.

I think you meant to say "more plates creates LESS resistance"
The more plates in the heat exchanger, the less pressure drop on the output. (Think bigger pipe)
The longer the length of the exchanger, the greater the heat exchange (Think hotter water for your shower output)

 

Excellent points. I've been aware of the Helton heat exchangers for years too, and I have always had the same reservations. But to this day I can't say I've heard of any negative issues.

I'm leaning towards doing it the way you did it.

I'm ignorant on the subject and you clarified it for me, I had it backwards!!! I'll probably use the same 20 plate that Spencer used. Out of curiosity where did you source the long 20 plate that you used?

Thanks again!

 

Will be getting this. http://www.outdoorfurnacesupply.com...RYn0aaU-nyHvzOJCuuZVAYtwWrTlpzAIzEaArha8P8HAQ

its on Amazon too.

 

My buddy works at McMaster Carr & brought me some. I think it was this
http://www.mcmaster.com/#general-purpose-hose/=spe4r9
I wouldn't use the clear stuff unless it's rated over your temp range- I steer clear of anything consumer grade if I can help it. Yes, you'll pay more and yes it's a pain waiting on shipping etc but stick to McMaster, grainger, fastenall & the such & you'll get the exact part you need that won't fail like Home Depot crap does.

Couple other guys have used the long 20 plates but I went for the more compact 40 plate & mounted it right next to the battery. It's tucked away nicely & cuts down on my length of hose needed which will make for less loss in temp on the hoses on the way to the exchange.

 

http://www.dudadiesel.com/search.php?query=b3-23a

B3-23A with1/2" Male NPT.

Ita probably overkill, there is a guy on expoportal with a 10plate 7.5x3 that works fine.

 

I'd get one with barbed fittings- you're gonna have to buy them to attach hose to that in the first place.
And I'm not sure where you live, but be careful - those are listed as MPT not NPT pipe threads. You might run into problems when you get it & no American fittings will attach to it

 

Here's the water pump I'm using. Was a spare for our old motorhome.
It says it can handle up to 40' of head! Which should kick ass for throwing a hose into a stream or whatever water source I can find.