Hot Water Project

[Rebel112r]

Hot Water Project

This project started a couple of seasons ago. Coolant hoses from Cummins needed to be replaced, so as I had system drained, I decided to replace water heater. I replaced heater with a Torrid 15 gal, dual heat exchanger unit. Having a second exchanger, I purchased an Espar hydronic, and three water to air exchangers and plumbed these in. Hot water mix from Espar, runs thru exchanger on Torrid then to air heaters and back to Espar. All works good, extra heat for boat, already have forced air Espar for main heat, and Hydronic makes hot water thru a Torrid, but it takes about as long as just cranking genset and using the AC side to make water. No Gain there. This week I replumbed the system, adding a 20 plate, plate exchanger, so house freshwater run thru plate exchanger, and hydronic hot water thru other side. Now I fire up hydronic, and in about 5 minutes I have hot water, for sinks and shower, Still testing but it looks like almost unlimited hot water, as long as hydronic is running. Pic later

 

[syjos]

Nice work!

What is that thing next to the WH?

 

[O C Diver]

I wondering if in the process of making hot water with the water heater, you were also pumping heat into the engine through the 2nd heat exchanger by means of thermal siphoning.

Ted

 

[Portage_Bay]

Nice work!

What is that thing next to the WH?

It's the plate heat exchanger.

 

[Rebel112r]

OC. I think that will happen, it is not something I need, but don’t see any downside. Heater is not on a thermostat, but is on a timer and is usually used for 30 minutes or less. The climate here makes preheating unnecessary.

 

[syjos]

It's the plate heat exchanger.

I didn't want to hijack this thread so started a new thread: plate exchanger vs tube heat exchanger

 

[Tolly Roger]

Timely thread for me as I am starting to plan out a system utilizing hydronic.

So, if I understand your set up, ALL your hot fresh water runs through the plate exchanger regardless if the hydronic is on or off.

Did you notice any pressure drop in the hot water with the heat exchanger in place?

May I ask where you sourced the plate exchanger?

Please keep us posted on the testing. This seems like a really good set up.

Thanks for sharing!

 

[Rebel112r]

Tolly R. Good questions.. The plate exchanger is plumbed into output side of hot water tank. There is probably some drop in water pressure, but I haven’t noticed it. The exchanger is from Badger Pipe.
https://badger-pipe.com/
We have put it to the real world test, works great for showers and dishes, so mission accomplished. If you are using hydronic for cabin heat, the plate exchanger, while running hot water will take most of the heat for the time hot water is being run. The little hydronic I have only flows slightly more than 1 gpm. I have a slight leak in a pipe fitting, so I am not completely finished with this project. The plate exchangers are cheap, and I am glad I did this project. Now I have to find a new project to keep me busy, good luck on your Tolly. I used to have a stern drive powered Tolly 26!

 

[Portage_Bay]

Another source for the plate exchangers is ITR in Vancouver Wa or Richmond BC. The Richmond store is much more helpful.

Another use for the plate exchanger is to capture engine heat. I have one between the output side of the hydronic heater and the engine cooling system. The hydronic cut off is 10 degrees lower than the engine at full operating temp. Once the engine is up to temp the hydronic will still circulate but won't fire. Cabin heaters and water heater all work normally.