Radiant hydronic floor heat mod?

[JWA]

Originally Posted by skoronesa

-Limit the amount of heat sucked from the coolant system minimizing shock to the engine

You don't run too much risk of damaging or even greatly affecting the engine's cooling system by adding an auxiliary heat exchanger such as your proposed radiant flooring. The engine's thermostat modulates coolant flow according to the temperature of the coolant as it passes over it.

While there are other issues with engine hot coolant acting as a radiant floor heater source how it would affect the engine cooling system relating to low temperature damage isn't one to be overly concerned about.

[skoronesa]

Originally Posted by JWA

You don't run too much risk of damaging or even greatly affecting the engine's cooling system by adding an auxiliary heat exchanger such as your proposed radiant flooring. The engine's thermostat modulates coolant flow according to the temperature of the coolant as it passes over it.

While there are other issues with engine hot coolant acting as a radiant floor heater source how it would affect the engine cooling system relating to low temperature damage isn't one to be overly concerned about.

I think you're right. I just know that with a boiler return temperature is very important and if it's too low will thermally stress the cast iron and cause it to crack.

[Orv]

I think you'd be OK as far as thermal shock, since when the coolant returns it'll be mixing with hot coolant from the normal engine cooling loop. Keep in mind every time the thermostat opens a whole radiator full of cold coolant gets dumped into the engine -- I've had vehicles where I could see the abrupt drop on the coolant temperature gauge when that happened.

[JWA]

Originally Posted by Orv

I think you'd be OK as far as thermal shock, since when the coolant returns it'll be mixing with hot coolant from the normal engine cooling loop. Keep in mind every time the thermostat opens a whole radiator full of cold coolant gets dumped into the engine -- I've had vehicles where I could see the abrupt drop on the coolant temperature gauge when that happened.

Because the thermostat modulates it tends to greatly eliminate those sorts of cold coolant shocks. Since the PCM likes to see a consistent CHT single a lot has been done to satisfy that requirement.

Where we measure temperature on the coolant can have a huge effect too. I've already added an Auto Meter temp gauge with a sender in the upper radiator hose. Interesting thing is I can have air warmer than ambient moving through the heating vents long before the temperature sensor shows anything at all.

I'll add another sending unit to a port in the coolant crossover tube---switching between the two while at operating temperature might prove interest.

Anyway good conversation here!

[Magnus_Barefoot]

Originally Posted by skoronesa

You bring up a good point. I would use a plate to plate heat exchanger to isolate the radiant from the cooling system. This would be placed in a visible location with bypass valves for the hot weather. It would require a circulator pump on the radiant side.

This would actually kill several birds with one stone.
-Eliminate the chance of a leak in the radiant affecting the cooling system
-Limit the amount of heat sucked from the coolant system minimizing shock to the engine
-Allow you to effectively stop the heat when you want.
-Allow you to run normal antifreeze in the radiant system and use standard al-pex instead of something compatible with the engines cooling system.

Thank you for your constructive criticism!

I like where this is going. It only requires an additional small circulation pump added to the load on solar system and solves the potential issue of antifreeze leaking in the cabin. Some radiant floor heating examples installed in vans I've seen require separate heaters for the coolant (water). This to me is incredibly energy intensive and not to mention wasteful of the heat being generated by the engine. Of course you would need to run the vehicle to get heat. Although as a thermal mass water is hard to beat and that heat can be held on to for a bit assuming insulation is sufficient.



If you've ever felt what it's like walking barefoot on a heated floor in a house in the dead of winter.. it makes a huge difference and it's actually quite subtle. The floor doesn't need to be anywhere near hot or even all that warm, the chill just needs to be taken off of it and you're in new territory.



I had a great chance to install something like this, except time is of the essence and I had to move on with getting my build done. Once I find a good penthouse top to put on.. I am adding this to the remodeling!


Great input all around guys

[TomsBeast]

For me, fewer systems means fewer things to maintain. Adding home-like systems to a rolling, flexing, home on wheels seems to ensure at least SOMETHING needs repair at all times LOL!

Radiant heated floor that only works when the engine is running seems of limited value in a camper van, even if it could be made 99% reliable. A floor heat system leak in the floor (of a typical camper build) would be a soggy disaster.

You could always build in a way to valve off the floor tubes 9in the event of a leak), but I wouldn't even consider doing this without separating the floor system from engine's cooling system using a water-to-water heat exchanger, as was mentioned.