I'm going to do this, but wanted to ask if any others have had success/issues with this.
1. 1.6gpm tankless propane water heater mounted outside of trailer, to keep combustion OUTSIDE -- with.
2. piping inside to a holding tank filled with glycol and using a
3. solar or other small hot water circulation pump wired to a thermostat.
When the thermostat calls for heat, it starts the pump, the pump circulates glycol from the holding tank.
The circulating glycol causes the tankless heater to light, which then warms up the tank.
The glycol tank is then a "thermal flywheel" where it will radiate heat slowly into the enclosed space.
The advantages are:
15watts for the circulating pump is the only 12v needed
Tankless heater is spark ignition from a pair of D cell batteries
glycol means nothing freezes
combustion is OUTSIDE
only space consumed inside is holding tank, or if you want - hydronic baseboard radiators
CHEAP -- tankless water heater is $100 or less, $15 for a pump, and a few bucks for a tank or radiators.
slow heat, no blasting hot/cold
so, anyone done this?