Heat Exchangers

KD702

Member
OK so I have been thinking of doing a heat exchanger for hot water. It doesn't seem that popular here in the US.
I guess I am looking for the Pros and Cons. I am also looking for options where to acquire one here in the US.

KD
 

Ramdough

Adventurer
OK so I have been thinking of doing a heat exchanger for hot water. It doesn't seem that popular here in the US.
I guess I am looking for the Pros and Cons. I am also looking for options where to acquire one here in the US.

KD

What kind do you plan on using? I plan on a plate exchanger for me. I have not picked it yet, but I would like to hear your thoughts.


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KD702

Member
What kind do you plan on using? I plan on a plate exchanger for me. I have not picked it yet, but I would like to hear your thoughts.

Well I am not sure, I just started exploring the idea. I have had some not so good luck with propane heaters, thought this might be the way to go for me. I would use it into the late fall time of the year and it seems to really be a more reliable option for what I want. most of the videos that I have watched are from Australia. I tried looking last night and was surprised how little I was finding here in the US. I guess I am wondering if I am not looking in the right place. I was thinking of using a mixer valve in the system.
 

J!m

Active member
I've been running a plate for a looooong time... 15 years at least.

Important tip: make sure you have a way to drain ALL the clear water from the HE. Ask me how I know.

If you know what you need, you can assemble them fairly cheaply from parts. I just replaced my plate, and it was $30 brand new via eBay. However, I had to purchase fittings (and custom make one) which eclipses the cost of the plate... I also designed and fabricated new mounting brackets, as the new one is smaller than the old one I had, and the old brackets were steel (and dissolved).

Then you need tubing, fittings (Home Depot), a demand water pump, water tank (mine is custom and sits behind the left rear wheel and is filled from inside), shower/sink connection point on the truck and that's about it. Optional (good idea) is a whole-house water filter between the tank and pump. I got some REALLY rusty water one time.

IMG_8198.JPG

Clear water lines are not yet connected in this image (and the forward one is too long anyway). I was able to use a Swagelok compression fitting (metric) on the forward connection; however, the rear connection is a unique size and I had to make an internally threaded connection with an o-ring face-seal for that... This HE is thicker (more plates) but less height and width compared to the one I had. But it's still 4000BTU/Hr. so plenty for a shower (or hot tea).

If you are not super-handy with designing and making custom brass fittings, you can contact Alfa-Laval, who made my first HE. The mount brackets are easy to work out based on my image above.

PS copper brazed 316SS construction. Mike Ladden had a copper tube HE that was crap and failed, so way back then I found a better solution, which is the plate by a long shot.
 

Ramdough

Adventurer
I've been running a plate for a looooong time... 15 years at least.

Important tip: make sure you have a way to drain ALL the clear water from the HE. Ask me how I know.

If you know what you need, you can assemble them fairly cheaply from parts. I just replaced my plate, and it was $30 brand new via eBay. However, I had to purchase fittings (and custom make one) which eclipses the cost of the plate... I also designed and fabricated new mounting brackets, as the new one is smaller than the old one I had, and the old brackets were steel (and dissolved).

Then you need tubing, fittings (Home Depot), a demand water pump, water tank (mine is custom and sits behind the left rear wheel and is filled from inside), shower/sink connection point on the truck and that's about it. Optional (good idea) is a whole-house water filter between the tank and pump. I got some REALLY rusty water one time.

View attachment 775182

Clear water lines are not yet connected in this image (and the forward one is too long anyway). I was able to use a Swagelok compression fitting (metric) on the forward connection; however, the rear connection is a unique size and I had to make an internally threaded connection with an o-ring face-seal for that... This HE is thicker (more plates) but less height and width compared to the one I had. But it's still 4000BTU/Hr. so plenty for a shower (or hot tea).

If you are not super-handy with designing and making custom brass fittings, you can contact Alfa-Laval, who made my first HE. The mount brackets are easy to work out based on my image above.

PS copper brazed 316SS construction. Mike Ladden had a copper tube HE that was crap and failed, so way back then I found a better solution, which is the plate by a long shot.

Very informative……

Would you mind posting a link for reference?

Could you post the dimensions, plate count, and fitting sizes?


Sent from my iPhone using Tapatalk
 

KD702

Member
I've been running a plate for a looooong time... 15 years at least.

Important tip: make sure you have a way to drain ALL the clear water from the HE. Ask me how I know.

If you know what you need, you can assemble them fairly cheaply from parts. I just replaced my plate, and it was $30 brand new via eBay. However, I had to purchase fittings (and custom make one) which eclipses the cost of the plate... I also designed and fabricated new mounting brackets, as the new one is smaller than the old one I had, and the old brackets were steel (and dissolved).

Then you need tubing, fittings (Home Depot), a demand water pump, water tank (mine is custom and sits behind the left rear wheel and is filled from inside), shower/sink connection point on the truck and that's about it. Optional (good idea) is a whole-house water filter between the tank and pump. I got some REALLY rusty water one time.

View attachment 775182

Clear water lines are not yet connected in this image (and the forward one is too long anyway). I was able to use a Swagelok compression fitting (metric) on the forward connection; however, the rear connection is a unique size and I had to make an internally threaded connection with an o-ring face-seal for that... This HE is thicker (more plates) but less height and width compared to the one I had. But it's still 4000BTU/Hr. so plenty for a shower (or hot tea).

If you are not super-handy with designing and making custom brass fittings, you can contact Alfa-Laval, who made my first HE. The mount brackets are easy to work out based on my image above.

PS copper brazed 316SS construction. Mike Ladden had a copper tube HE that was crap and failed, so way back then I found a better solution, which is the plate by a long shot.

Thanks for the info. I am starting to tinker with the schematics for my Tundra. when you said:

"Important tip: make sure you have a way to drain ALL the clear water from the HE. Ask me how I know."

Were you talking about when not in use or during the cold weather months?

KD
 

J!m

Active member
Yes, mine froze and separated the plates, so the coolant was getting into the clear water.

Just search plate heat exchanger on eBay and you'll find many. There is no point linking mine, as the fitting had to be custom made. Spending a bit more might find NPT in and out and/or standard diameter fittings for a Swagelok compression fitting to fit. The one I got is designed to be welded or brazed by the end user. I was able to work around it, but it was certainly non-standard. If you have the engineering and fabrication skills to make o-ring sealed fittings, you can work out the rest.

I don't think it's possible to get a plate that is too small for a shower, so that shouldn't be an issue.

Alfa-Laval is a premium brand, but the pressures and temperatures are not extreme in this application (so don't over-think it). Stainless steel with copper braze is about as good as it gets, but you might come across exchangers of more exotic materials/braze. NOTE: do not connect with cast iron (black iron) fittings, as they will corrode quickly attached to stainless. Use stainless or brass only. Stainless preferred on the clear water side, but brass is also fine. You don't want galvanized or black iron on the clear water side either- you can easily preserve potable water with careful thought and planning. Even PVC is okay as long as it is protected from extreme vibration and temperatures (on the clear water side). I have PVC tee fittings to divert coolant to my rear heater with no issues after many years of use.
 

KD702

Member
Thanks for all the Info J!m.

Living in the north where we have winter temps 6-7 months a year, I was concerned with the freezing issue. The power of frozen water is incredible. I was thinking of plumbing in a way to blow out the clean water line(s).

Just so I am clear, since this truck is my daily driver, the Plate is fine to run with just the coolant circulating through it on the days not in use.

Size was a question I had as I did not want to restrict the flow of the coolant and create a separate issue with my heater core.

Why isn't this more popular here in the US? Seems like a simple solution for reliable heated water and removes another peace of gear from having to haul.

Thanks again,
KD
 

J!m

Active member
Mine has coolant running through it all the time. Not an issue. And it increases your total coolant capacity as well.

Actually, coolant runs through two heaters and the plate in my truck. I was able to get the interior up to 85 degrees (F) in the arctic and then we had to open the windows because we were dying in there (-22 F outside). Purely for scientific knowledge of course.

"How hot can we get it in here?"

"Hold my beer."
 

J!m

Active member
Well, no, because there only so much heat available to transfer, and the "rating" is based on maximum flow on both sides (which you won't have).

It "boils down" (HA!) to cost and physical size. You need to pay for it and mount it somewhere. My new one is smaller but thicker (more plates) as compared to the original one I had. But same BTU/Hr. rating (or thereabouts).
 

KD702

Member
Well, no, because there only so much heat available to transfer, and the "rating" is based on maximum flow on both sides (which you won't have).

It "boils down" (HA!) to cost and physical size. You need to pay for it and mount it somewhere. My new one is smaller but thicker (more plates) as compared to the original one I had. But same BTU/Hr. rating (or thereabouts).

I decided to go with 3"x8" 20 plate. It will be interesting to see if a mixing valve is needed. Looks like it has 2.85 sq feet of heat exchange area. I am hoping this will do it, because then I seen a 26 plate for $10 more that has a 3.75 Sq feet.
 

J!m

Active member
I use a home shower valve as my "mixing valve" and you control temp and flow in real time as you shower...

Here's an (old- 2004!) pic of the hoses hooked up. I'm sure you can work it all out with some quality time in Home Depot...

Shower Time.jpg
 

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