Heated floors

[Natgreen]

I been kicking around an idea for awhile. Getting a solar water heater then put tubing in the floor and circulate anti freeze so you can have heated floors. I'll admit I haven't looked into it much. It's just brainstorming for me. Has anyone else done This? Or know if it can actually be done.

 

[MrNoodly]

Or how about a small propane powered on-demand water heater?

 

[maki2]

Some vans that have diesel power have a circulation heating function from off of the engine that is used for heating the floors of the RV. So not an unheard of practice. It also uses a heat exchanger (again using heat from the engine) to heat water for the household use such as showers. But it is most useful when you have been actively driving for a while then set up camp and take your shower right after you stop driving.

 

[eDJ_]

On the old CRVL forum I had designed an on demand propane hot water heater system that would circulate hot water thru a "PEX tubing" single zone, run on the floor under the flooring/carpet.  It used a Toyota Prius electric water pump connected to a Bosch relay that was triggered by a mechanical thermostat.  (and connected to the house battery) 

When the temp got low enough the thermostat would trigger the relay to close and energize the electric water pump to circulate coolant thru the water heater which would sense the flow and ignite.   As the hot coolant would circulate and heat the floor in time the thermostat would sense the upper limit of heat.   (the temp the thermostat was set to maintain)  and break the relay's contact with house power....and thus shut down  the water pump causing the hot water heater to shut down).   This would provide for cyclic heating similar to a house with a boiler and baseboard hydronic heating.

The pump doesn't have brushes and is a sealed unit, capable of a long life.

The main thing is venting the propane water heater to the outside and there should be some provision for expansion of the hot coolant. (like a small tank)   I would also suggest some consideration be given to a vent to allow outside air for the burner of the water heater.


The floor would have to have 2X4's secured to it in a manner for the PEX tubing to run thru it like a maze such that the pump pumps the hot coolant into the zone (maze) and the cooled coolant returns to the inlet of the hot water heater.
(pumps tend to push better than they pull)  The elevated flooring may have a couple of long narrow metal grates that can be opened or shut (when not needed).

I've thought of a few other ways of doing this but I think this would be the simplest way to go.

 

[eDJ_]

Here is a basic sketch of the system I've described if anyone is having trouble visualizing it.

The floor would have to have boards such as 2x4's  with space between them for 3/4 inch PEX tubing to run in between them and to form a loop as shown.  Plywood would cover this construction. It may not have to cover all of the Van's floor space to heat it.  Say from in front of the bed to a couple of feet behind the driver/passengers seats. (thus providing an area for ice chest so it isn't sitting on a heated floor)

Thin strips of foam insulation could be placed in these channels for the PEX to lay on.

I've not shown the wiring diagram but it is simple as the 30 amp Bosch Relay has 5 points to connect to ground and the other items such as the Thermostat, Battery, and Pump.  I believe the hot water heater ignition is piezoelectric so it doesn't require an electrical signal to ignite.  But in this case the Thermostat needs to be "mechanical" such that it's points open and close as a mechanical function.

I haven't built this system (yet) but if and when I do this will be the plan I use.

 

[Natgreen]

Keep us updated. Thanks for the input.

 

[ckelly78z]

I really like the idea of having warm feet, more so than hot air blowing at me from a furnace/heater. Thanks for the idea.

 

[B and C]

Down booties work well for keeping feet warm. I have a furnace but still wear the booties inside when my feet are on the floor or lounging with my feet up. Cheaper and easier plus no worry of leaks.

 

[highdesertranger]

yeah no KISS in this thread. highdesertranger

 

[eDJ_]

I haven't discussed the wiring of the 5 post Bosch 12 V Relay.

Here  is the relay explained:




Any electricians here want to suggest how to wire the relay to the battery & pump....and the thermostat if it need to have an electrical signal routed thru it ?
I understand the water heater self ignites with a piezoelectric device when it senses flow of fluid thru it. 

If I were using one of these I may have a Carbon Monoxide Detector in the Van (or maybe 2 for redundancy)

 

[Spaceman Spiff]

Unless you insulate under the heating element you will loose about 1/2 your heat out the floor of the van.  The amount of heat you loose is directly proportional to the insulation under vs. over the heating element.