heat exchanger hot water using rear heat

[TeleSteve]

Here is a few pictures of my setup, the heat exchanger is surprisingly small.
The 1/2"copper passes through the floor through 3/4" water tight strain reliefs.

The water lines are plumbed with 1/2" PEX. The silver looking valve is the tempering valve to keep the hot water tame. This valve works really well, you could probably eliminate the shower mixing valve and just set this where you like it.


It was a tight fit but I managed to fit all of that in a box in the back corner behind the seat.

[Glider]

Great photos, TeleSteve. Do you have any pics showing how/where you tapped into the engine coolant system?

[86Scotty]

That's perfect Steve! It's like you read my mind.

[TeleSteve]

Originally Posted by Glider

Great photos, TeleSteve. Do you have any pics showing how/where you tapped into the engine coolant system?

I don't it was pretty tight in there. I pulled the doghouse off to get to it. I put the bypass valve on the return hose from the heater core about 10" from the firewall.

[Glider]

Originally Posted by TeleSteve

I don't it was pretty tight in there. I pulled the doghouse off to get to it. I put the bypass valve on the return hose from the heater core about 10" from the firewall.

More questions:
1. Does the bypass valve go straight into 1/2" copper?
2. Did you insulate the run to the back of the van?
3. Does your loop come back to the heater return hose right behind the bypass valve?

Thanks!

[Flux]

Really nice work TeleSteve!! And many thanks for linking all your hardware too.

[TeleSteve]

Originally Posted by Glider

More questions:
1. Does the bypass valve go straight into 1/2" copper?
2. Did you insulate the run to the back of the van?
3. Does your loop come back to the heater return hose right behind the bypass valve?

Thanks!

The bypass valve connects to heater hose. I ran silicone heater hose along the frame all the way to the back of the van where it connects to the copper before going through the floor. (similar to heater cores)
No insulation, there is plenty of heat from the engine I wasn't worried about any heat loss.
The exchanger return line connnects back to the bypass valve. The bypass has 4 ports, 2 for where you cut into the existing heater return hose, and two for the exchanger loop.

Here is the switch on the dash to activate the vacuum solenoid which controls the bypass valve.

[Glider]

Beautiful. Thank you!!!

[Dirk Mitchell]

Great info here you guys are awesome!!

[Glider]

With apologies for my lack of knowledge on this point: is coolant always flowing through the heater core, regardless of cab heat being on or not?