Where to tap coolant for a shower heat exchanger?

[greiswig]

I figured there might be someone who has done this already, so I thought it wouldn't hurt to ask. Several years ago, I got a used FlatPlate heat exchanger that I'd planned to use as part of a methanol recovery processor when I was making a lot of biodiesel. Then I stopped making biodiesel.

Fast forward to today, and I'm kitting up my LR4 to do a bit of overlanding. My lady likes showers (and so do I), so I've been experimenting with how to make a good solar shower like they did on LR Time, even going so far as running an experiment with a half clear/half black container's performance relative to an all black container.

But then I remembered that heat exchanger. The idea of being able to mount that somewhere, have 10 square feet of exchanger area at a high flow rate, and basically flip the switch on a 12V pump and have water running through that with the engine warm and get hot water out instantly...pretty tempting. I've done something similar before on another rig, and was able to put a valve in there to control the amount of bypass around the heat exchanger to help control temperature. Worked well.

The exchanger I have has 1" MPT inlets and outlets. I'm wondering where the best place to tap into the coolant system might be to feed this. Any ideas or thoughts?

 

[djkaosone]

There's a n-i-p-p-l-e on the front crossover pipe that is already open. On the V8 there's a cap on the n-i-p-p-l-e at the y-pipe. I'm sure there's something similar for the newer LR4s. Not 100% sure about this, but it looks like the '14 and up has a different pipe that has a cap (#22). Maybe you can just remove the cap and that's where you can tap in.

The nice thing about it is the coolant is coming directly from the engine where it's nice and hot.

 

[greiswig]

Thanks for helping me think this through. I think I'd be looking for greater flow than that would provide. I'm not even sure those two points represent two sides of flow. I need to basically plumb this exchanger into a section of the cooling system that sees a fair amount of flow, ideally before the thermostat. On the one I did before, I just cut a section of the lower radiator hose and put it in there, and had made my own copper coil exchanger that fit there.

This is a pretty high flow exchanger: the specs say that the "minimum required flow rate" (whatever that means) is 20GPM, and that I can expect a 7PSI pressure drop across it at that flow rate. I'm not sure how much the stock pump actually flows at full open thermostat, but thinking about it that is probably where I should have started.

 

[Stuart Barnes]

Can you do a straight swap for the rear heater in the 3’rd row?

 

[Nechaken]

There's a n-i-p-p-l-e on the front crossover pipe that is already open. On the V8 there's a cap on the n-i-p-p-l-e at the y-pipe. I'm sure there's something similar for the newer LR4s. Not 100% sure about this, but it looks like the '14 and up has a different pipe that has a cap (#22). Maybe you can just remove the cap and that's where you can tap in.

Love the filter.

 

[djkaosone]

What if you tapped into the upper coolant hose? That's where the hot coolant flows out. Maybe use something like this, but with the right diameter to tap?

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[avslash]

Passenger side rear wheel well there are coolant pipes for the rear hvac. I believe they are 3/8, so probably more flow available than the crossover ******.

There is also some room behind the passenger side cargo area trim that might make for a suitable location for the exchanger. Any leakage would make for an interesting repair, however.

This is a very interesting idea. Please report back on your progress.

 

[ktm525]

A solar shower works wonders too.

 

[djkaosone]

I like the idea of having an on-board heated shower. Better than lugging this thing around with water and propane, less things to carry.

 

[greiswig]

What if you tapped into the upper coolant hose? That's where the hot coolant flows out. Maybe use something like this, but with the right diameter to tap?

The problem is that I can't just tap it. I have to insert this in series with it.

Looking over this diagram, that section of the upper hose, or at the section that Tees off toward the thermostat, might be a good place. Provided this thing doesn't restrict flow to any appreciable degree.