In-floor Heating from Auxiliary Heater Coolant Lines

[SnowBikesLeft]

Hi,

New to Posting. I just bought a 2006 Ford E350 Shorty. Tried to do a search but didn't find too much on this particular subject.

I have aa stock auxiliary heater for the cabin of the bus mounted under a seat just in front of one of the rear wheel wells. I also have a Coolant isolation valve mounted externally behind the drivers seat. I was wondering if anyone had removed this heater and extended the coolant lines through the new subfloor and insulation to create hydronic heating. Obviously it would only run when the engine is running, but would this be a cheap/worthwhile installation to heat the floors while driving/idling in the winter? I assume there would not need to be any additional pumps installed, just additional coolant added to the circuit?

Thanks in advance!

Cheers,

Dan

[Simplicity]

Eh, this sends up red flags for me.

1) In a stationary home, yeah. But, in a moving, rock n roll bus....to much movement. If you have an issue, it's UNDER your floor.

2) I don't see any upside to this from a heating perspective. As you said, it would only work when the bus is running. I can't see using in floor heating when driving or idling, because you already have plenty of heat. Especially in a small bus.

3) So many other cool things to do with your time, creativity and money then running water lines under your floor.

[CHEESE_WAGON]

I second what Simplicity said. It's doable, but care must be taken to combat the special problems that present themselves in a mobile environment. And, yes, an additional booster pump is required to maintain flow. All buses with factory auxiliary heaters have them.

I might also add that should such a system spring a leak, your conversion is effectively ruined because the floor must be pulled up to asses the damage, unless a little thought and attention to accessibility is given.

[joeblack5]

That is very well possible..
But..
The coolant gets hotter then normal pex can handle. Also the pressure when the engine accidentally overheats together with the temperature will make pex blow out.
You would need a mixing valve with likely an additional pump. Max temp around 150f .
From a safety standpoint it would be better to get a flat plate heat exchanger.

The floor heat would likely not enough to heat the bus by itself..some depends on insulation and outdoor temp..wind-chill etc... In Dory we have added an additional radiator for temps below 40F. But a warm floor is nice..

If you plan to add a diesel coolant heater in the future then floor heat is very nice.

The main advantages of floor heat is that it is quiet and very efficient from an electric point of view.
Having a diesel coolant heater also opens up more options for domestic hot water and pre heating the engine.
In a small bus that would lead to some space saving.

Good luck.
Johan

[SnowBikesLeft]

Thanks for the prompt response guys!

After taking that on board, I may try and use those coolant lines around an insulated undermount greywater tank instead, that I can turn on in the winter to keep it from freezing periodically. Otherwise I'll just isolate them and move onto to the next task!