Tiny home in floor radiant hydronic heating (warmboard) help

tinyhomeheathelp

Hi! I live in an area where people don’t want to touch tiny homes for gas work so finding info about how to run my warmboard hydronic heated floors has been challenging. I want to use propane to heat. I have 120 ft of 1/2 inch pex in a single zone. I don’t know what kind of heater (I was thinking on demand but don’t know how to regulate the flow) and what kind of pump and thermostat. I am at a loss on how to build this system! Thanks in advance. 

hot_rod

About the only small enough lp heater is a 6,000 btu/ hr water heater. They are noisy and fairly inefficient
When you run a heat load on a tiny home, it is tiny also. I used a small electric boiler on an 8x20’ home I built. I actually downsized the element in the Thermo 2000 boiler.

One thing to be aware of is the amount of actual floor space to cover the load. With built ins you end up with maybe a 3’ wide strip of useable radiant floor heat. Mine was spray foamed and had good windows, so the load was under.2,000 btu/ hr. The heat from cooking or running a small over is about all you need for heat🤔

Larry Weingarten

Hi, I'll add that if you live in an area that gets cold, you could add radiant tube or panel radiators to the walls to get enough surface area. This might be a case where a dedicated tank-type water heater will provide enough heat. On demand heaters have so much flow restriction, that they aren't a good fit for radiant heating.

Yours, Larry

Mad Dog_2

I like a small tank type water heater even electric if rates are Low in your area. Mad dog 🐕 

Hot_water_fan

If this is grid connected, I’d use electricity, it’s just easier. 

hot_rod

This looks like a nicer design for for RV use
My brother in law put one of their lp furnaces  in a 24’ camping trailer

https://www.propexheatsource.com/heaters/malaga-water-heater/

bburd

hot_rod said:

This looks like a nicer design for for RV use
My brother in law put one of their lp furnaces  in a 24’ camping trailer

https://www.propexheatsource.com/heaters/malaga-water-heater/

That heater has a maximum working pressure of 29 psi, and "must not be connect to a mains water supply" meaning public water or well tank, which operate at higher pressures. Probably not right for the application, but there must be something out there that is.

TAG

What are you using to heat the domestic hot water

hot_rod

bburd said:

hot_rod said:

This looks like a nicer design for for RV use
My brother in law put one of their lp furnaces  in a 24’ camping trailer

https://www.propexheatsource.com/heaters/malaga-water-heater/

That heater has a maximum working pressure of 29 psi, and "must not be connect to a mains water supply" meaning public water or well tank, which operate at higher pressures. Probably not right for the application, but there must be something out there that is.

My thought was to use it as the radiant heat source. A 20 psi relief could be added. It could run at 5 psi fill pressure

Alan (California Radiant) Forbes

https://www.janesradiant.com/small_point-of-use.htm