Engine heat exchanger

[Bearmtnmartin]

I am repowering my bus and Bluebird ran coolant lines straight from the motor to the house heat exchangers. I want to add a coolant to coolant heat exchanger so if I get a leak it does not drain the motor and radiator. I am wondering if someone can give me a model number or take a photo of one for me.
Thanks

[freds]

I am repowering my bus and Bluebird ran coolant lines straight from the motor to the house heat exchangers. I want to add a coolant to coolant heat exchanger so if I get a leak it does not drain the motor and radiator. I am wondering if someone can give me a model number or take a photo of one for me.
Thanks

Sounds like you are starting from the same basic layout that I had.

Though I took it in a different direction with my DIY Hydronic system.

Which I have posted a lot about in my build thread: https://www.busconversionmagazine.com/forum/index.php?topic=34318.0

Back to your topic I have never heard of someone doing this  or this being a feature and I image the actual failure rate is minuscule.

If you did have a heat exchanger then you would also need separate pumps, expansion tank, etc.

Most buses do have  manual values to shut off the flow through these lines if a leak is detected.

Maybe a better focus would be to make sure the low coolant level alarm works and to have flood detectors in the bays where leaking coolant from this circuit would collect.

[Bearmtnmartin]

I'm not sure why I would need to add anything except the heat exchanger. It would just provide a measure of safety. I actually thought hydronic systems with engine preheat all had that feature and mine was missing it but perhaps not. I do not currently have an expansion tank unless the hot water tank functions as one. The hydronic system has the same pressure as the radiator cap I guess. It has always worked fine, heating the house with engine coolant heat. I will read your write up tomorrow. Thank you for the input.

[buswarrior]

Flat plate heat exchangers were often quoted, by those who wanted to keep systems separate, but share the heat.

I have swung back and forth over the years, whether to isolate or gang it all together.

Remembering that there's a fresh water supply onboard, from which to replenish whichever life support system the moment demands... some carefully positioned valves in order to isolate and then regain function on either side is my current bias.

Coolant boiler, generator, prime mover, domestic hot water tank, solar power dump, all represent a source of "free heat" depending on the situation.

That we try to harvest it, is a worthy design exercise. How we go about it... that's why we build our own!

Happy coaching!
Buswarrior

[RichardEntrekin]

Bear,

When you add the heat exchanger, you will have to add a circulation pump to the new loop, since the circulation from the engine will only move coolant through one side of the exchanger. Something will be required to move the coolant in the other side of the exchanger.

[Bearmtnmartin]

My bus is a Wanderlodge, and it came with a circulation pump that runs the coolant through three radiators through the bus and also the hot water tank. It is simple and effective. All i want to do for the moment is seperate the house circuit from the engine circuit, which is something I think bluebird neglected to do. I dont want to lose coolant until the low coolant light comes on. That could be gallons and there are 70 feet of one inch hose that could leak. It seems like a simple way to limit trouble, but i am not sure how big an exchanger to get.

[buswarrior]

Equivalent btu exchanger to the combined heat exchangers.

Those will be off the shelf heaters, are there any labels on them? The rating might be right there? Otherwise measure them, and compare to the supplier's catalogue.

Wanderlodge community may know ?

Happy coaching!
Buswarrior

[Bearmtnmartin]

I see Brian Diehl has done the same thing. He uses a 100,000 BTU flat plate exchanger which apparently works well so I bought a similar one.