My hot water project

[TrickyT]

Nice writeup, Rami. I wonder how the efficiency of your heat exchanger compares with the Helton unit I have. You list the key empirical data for your unit, so maybe I can test mine and post up results sometime. In the mean time, I'll just say that if I throw my hose pickup into a cold stream and have my '80 running at a fast idle, the water coming out makes for a very nice shower.

 

[rhyary]

Thanks TrickyT and thanks for your contribution.

I only tested at idle.
Touching the water at first pass felt warm without the restriction if the shower head. Remember this adds 1/4" I. D. Restriction meaning is slows down the flow and the water spend more time per pass inside the heat exchanger.

If the stream is warmer than 40, it makes a huge difference as streaming (essentially one pass) create the most temp differential.

Yes if you can create empirical data for Helton that can be excellent.

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[Trollhole]

My braised 6 plate heat exchanger I use has these numbers. They don't see the 6 anymore. Just the 8 or 10 is the smallest the sell. I'd think you would get quite a bit more performance out of it.

pump is 3.5 gpm

cooler water temp -----engine rpm---- output temp

60--------------------------800-------------- 85
60 -------------------------1200------------- 95
60--------------------------1800------------ 110
40-------------------------- 800 -------------65
40------------------------ 1200 --------------85
40------------------------ 1800 --------------100


All of thes #'s were with the hot all the way on (3gpm)

At about 2 gpm I could get 125.

Pics

 

[hesterj]

Where did you find that heat exchanger? Nice looking set up

 

[rhyary]

Trollhole,
I investigated the braised plate design and I decided against it after talking to engineering at the heat exchange manufacture. The plate H-E was not design to be in a vibrating environment, not going to take a rock flinging into it during off-road. It is a much more delicate device. I went the unit shown in this thread for the bombproof design. The unit I selected can take the abuse of off road and then some. The brass and cast bronze are tested to 300 psi and the tube side to 150 psi. And will not corrode by salt water. A cheaper version is brass shell and cast iron bonnets, but I did not want one more thing that will rust on the car.

Not saying the plate is not good or efficient, but being at CM2011 and doing a trail by myself after the event I realized first hand the feeling of being along, to me, reliability and overbuilt is what I wanted. Just like the rest of the LX450, everything is overbuilt an so is the H-E.

 

[rhyary]

My heater lever was all the way hot and fan was on low. Rear heater off.

You know, I never thought about changing the engine RPM, and I do have the hand throttle. :-(
However increased RPM uses more gas, and gas and water may not be found on the trail easily. So conservation is key.

 

[rhyary]

Nice looking set up

Thank you.

 

[Trollhole]

Trollhole,
I investigated the braised plate design and I decided against it after talking to engineering at the heat exchange manufacture. The plate H-E was not design to be in a vibrating environment, not going to take a rock flinging into it during off-road. It is a much more delicate device. I went the the unit shown in this thread for the bomb design. The unit I selected can take the abuse of off road and then some. The brass and cast bronze are tested to 300 psi and the tube side to 150 psi. And will not corrode by salt water. A cheaper version is brass shell and cast iron bonnets, but I did not wanted one more thing that will rust on the car.

Not saying the plate is not good or efficient, but being at CM2012 and doing a trail by myself after the event I realized first hand the feeling of being along, to me, reliability and overbuilt is what I wanted. Just like the rest of the LX450, everything is overbuilt an so is the H-E.

I agree. That certainly is a bombproof design. That being said the place I got mine from are extremely heavy duty. I couldn't imagine a rock would dent it. It's basically all stainless. I've put mine through a lot of abuse and it's done just fine.


Do you have your HE plumbed in before the heater or after?

One question. Can you drain all the water out of it? If it freezes what happens? I'd think that thing would be fine but it wouldn't hurt to test it or at least ask the manufacturer.

Going up to the bigger pump was a good idea. You can never have too much flow. I had never thought of recycling the water back into a container to make it hotter. Good idea. I usually just plop the hose in a water source and let it run. Though I have to carry a lot of hose.

 

[rhyary]

The HE is plumbed after the heater.
When I am done with the water, I blow into the intake hose, which clears the water left in the H-E, and I collect the water that comes out of the output.

Long hose waste water and I have to put it some where in the car. With the hoses I have the whole package fit into a Walmart plastic container shown in one of the pictures.

If I have a stream, I can refill the 5 gal as many time as I want. If I don't, well then I have to conserve water anyway.

Everything in my car is a delicate balance between balk and usefulness. Yes I can take longer hoses but that get balky. If I take shorter hose, well then I can't stick it into a stream. taking a longer hose is very easy so if I am wrong, it can be remedied quickly on the next trip.

 

[cody c]

So heat exchange ready for install. First a threaded the fittings as much as I can using thread sealer. In this picture it was only threaded by hand.
But the problem with NPT is that it is a tapered thread and you can't thread it much more. I wish there was a way to trick the threads and thread it all the way in.
Everyone I asked in the plumbing stores said it can not be done. Meh!

If it was me, I would use a NPT tap and run it a bit deeper into the threads.

You would risk bits of metal falling into the housing, but you could probably run compressed air to the fitting on the opposite side while you run the tap in to push the metal out. You would also want to put the threads to the side instead of from the top while running the tap into it.

There is also the risk of cracking the housing if you apply too much force, but that should be able to be avoided with experienced hands...

Although, there may be something blocking the tap from running deep enough just below the threads, which could cause damage.

Advice from plumbing stores? Might as well get advice from politicians. ;p

It mentions a sacrificial anode (zinc) for the disimilar metals, wonder why they dont use stainless body/fittings? Other than cost.

 

[rhyary]

If it was me, I would use a NPT tap and run it a bit deeper into the threads.

Now you telling me

There is plenty thread going in. There is no functional risk.
It would have been providing a better clearance.
But, it turned out I didn't need more clearance.

There is also the risk of cracking the housing if you apply too much force, but that should be able to be avoided with experienced hands...

No experienced hands but no risk either using common sense.

 

[scarydriver]

The very well documented and organized write ups like this one are the reason I love forums so much. Thank you for taking the time to write this post!

 

[locklin]

Very nice write off!

If I weren't in Venezuela I would be one of the 10+ persons you need to lower the costs.... Maybe I can talk to my brother who lives in Miami and send everything to his house...

About how much will the whole kit costs?

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[locklin]

Very nice write off!

If I weren't in Venezuela I would be one of the 10+ persons you need to lower the costs.... Maybe I can talk to my brother who lives in Miami and send everything to his house...

About how much will the whole kit costs?

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I meant "write up" ...

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[alia176]

Looking good!

Here's an idea of mounting the hot/cold water connections. Mine is in the passenger front wheel well. The 12vdc power plug is to run the tiny pump for my Helton HE system.

One thing I suggest you experiment with is water flow and pressure. On the trail, water conservation will be important so the least amount of flow you can live with while maintaining a high degree of pressure is a good compromise. With that said, I have a penny with a tiny hole in it inside of the shower wand. This works pretty well for me and does the job on the trail.

Another thing I suggest is installing two isolating valves for the HE. Should something happen in the field, you can isolate the HE from your cooling system. They're also a good thing to have if you have to service the HE and have to pull it out of the vehicle. The cooling system stays closed while you service the HE. Just a thought.

Cheers.

 

[rhyary]

Alia176,
Have you measured the amount of water you need for one shower on the trail?

For safety this will stay in the truck

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[alia176]

Alia176,
Have you measured the amount of water you need for one shower on the trail?

Typically, we tend to use up about 1.5g/male. Here's my typical operation:
- wheel all day, find a camp spot for the night
- bring a 5 gallon water can out and recirc the water with engine on idle while it's cooling down. Usually two cans are heated for a group of six guys.
- while the water is heating up, we setup camp and start cooking.
- setup shower tent next to the 80, shut engine down.
- take the water can into the shower tent and start taking military showers
- when not using the shower head (lathering up), keep it running but toss it into the water can so the water can keep on recirculating.
- rinse and repeat as they say

 

[rhyary]

Excellent information.
My pump has pressure switch, so when I let go of the shower head lever, it stops the pump.

So if I understand correctly, you throw the head back into the container because you don't have pressure switch?

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[rhyary]

Also,
I set up the quick connects so that I can disconnect the water hoses from the car, connect to each other and not having the H-E in the loop. That allows me to set up the shower tent toward the rear of the car, where most of my stuff is located including the electrical outlet, with short hoses.

It also allows me to continue to idle the engine for other needs.

From your practical experience do you think this setup be usefull?

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[spressomon]

Excellent information.
My pump has pressure switch, so when I let go of the shower head lever, it stops the pump.

So if I understand correctly, you throw the head back into the container because you don't have pressure switch?

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If you have an unlimited water source it works great, especially when there's more than a couple of showers that need to be taken, to drop the cold water pickup into a lake/stream and let the shower head end free flow until all showers are done (use heater control valve or engine rpm to adjust water temp). If you shut the flow of water, in the above scenario, in between showers/military style lather ups, the person taking the shower will get a super heated blast of water when the flow from the shower head is returned. That's why its best to let it free flow until all showers are finished.

Or most of the time since water is not typically readily available for most of our forays in the dry western USA we heat a container (I use a 20L Scepter water can) of water to the desired temp and then pump out of the container for the shower water. Then, by using a simple kitchen sink type sprayer with on/off flow trigger, we take a very water conserving military type shower...without the issue of getting that super heated blast if pumping directly from the HE when using on/off shower head. Although if the ambient air is cold you'll get a short burst of cooler water when the flow is returned...pick your poison I guess

I can typically heat 20L of ambient temp water to good shower temp in less than 10-minutes.

Although a modern day penny is copper plated steel I drilled a small hole (sorry...I can't remember what size drill bit I eventually used after testing various flow rates from different size holes in the penny)...inserted in the base of the shower head handle. I get household type shower spray pressure with this set-up and my high volume Shurflo/Aquajet (I have two set-ups...one for the KK and one for the LC) but at only .75gpm, real world, its "win-win".



Dan