Camper radiant heat and engine cooling circuit

[bulya]

Hi, has anyone built a camper radiant heat system connected to an engine cooling circuit?

I have 1993 MB 814DA (Vario) that I am currently converting into a camper. I am thinking about installing radiant heated floors, install additional coolant heater and water pump and use truck cooling circuit for heating. It would go both way, during driving it can keep cabin warm, and during camping you can pre-heat an engine. I thought about 2 ways to do it, 1 loop between truck and heated floors, or 2 loops connected via heat exchanger (would need 2 pumps for engine pre-heating and cabin).

My concerns are:
* significantly extending a circuit and stressing truck water pump with 1 circuit system
* cooling liquid being "too cold" during cold weather with 1 circuit system
* heat exchanger inefficiency with 2 circuit system

If anyone has experience with these types of system and can advise resources/tips/any info - I would appreciate it.

Thank you!

 

[Peter_n_Margaret]

Our Webasto diesel heater heats a 30L calorifier hot water system that also supplies heated glycol for central heating the living space.
That calorifier can also be heated via a 100W element powered from solar powered inverter and it has a separate heat exchanger coil heated by the engine waste heat.
It can also be used in reverse by heating it with the Webasto to pre-heat the engine before starting in cold conditions.
After driving 20 minutes we have 30L of HOT water. It can be turned off, but we never need to do that.
Works a treat and I will be doing similar for the new build.
Cheers,
Peter
OKA196 motorhome

 

[Joe917]

Our MB917 has 3 radiators and a 20l hw calorifier in the camper. connected directly to the engine loop. Shut off valve on one side of the loop with a Webasto heater on the camper side. The system has run without issue for30 years. (Webasto replaced once and calorifier replaced once). The Webasto is controlled by a Slimline Tstat. Camper heat from Engine or Webasto, any combination of radiators and hwt ,engine pre heat, any one or all.
No need for a heat exchanger, this eliminates extra pumps.
Webasto pump can handle the entire loop no issues, same for engine pump.
An underfloor loop would be nice but temperature control might be an issue.