We set the expansion tank and diesel heater in their approximate final positions this week and started up the system.
It took only a couple of minutes to circulate less than 2 gallons of the water/ethylene glycol mix all through the 70’ of heater hose coolant lines.
There were no leaks, not a single one. We had to bleed captured air off, using a flat blade screwdriver, at the heater’s outlet before the circulation pump would run smoothly.
Once running, we could detect NO sound from the pump. We had to touch it with our hand to confirm our suspicion that fluid was traveling in the line.
When the unit first starts the circulating pump, ceramic igniter and combustion air fan all come on together and there is a not unpleasant whine which lasts 60 seconds.
When combustion starts it is barely audible. I would say the constant sound is about the same as the new Flojet water pump inside the trailer.
This silence was helped by the fact that we’d exhausted the plant to the outside of the temporary workspace.
So we tested it with the exhaust inside the shed. There was more sound but you could conduct a conversation in a normal voice.
The sound is much less than the little Japanese generators make, for instance. It’s also less than the sound a propane furnace exhaust makes.
Nevertheless, in the final set up, we will add a small muffler. The system will then be whisper quiet.
So we have no sound to speak of and no smell outside.
Inside the trailer there is complete silence. You can’t hear the fluid moving in the rubber hose of course. There is no sound of a gas furnace coming on and off. No ducts so no air turbulence. Just the quiet hum of the little 1.5 amp fans in the three fan coil units.
The little Webasto heater on the trailer tongue measures 9” x 4” by 6.4” and weights 7 pounds.
Operating on 12v
it draws 5 W at high and 2.5 at low. Full heat is 17, 200 BTU. Reduced heat is 8,600.
It consumes 0.16 gallons of diesel per hour at high and .08 at low.
It’s a very, very sweet set up. I’m happy to see all the work result in such a nice system.
These are photos of the small wall thermostat used to control the fan units and the 11.5-gallon diesel tank, complete with pump.
The tank is mounted under the trailer, just forward of the axles.
The hole at the right front is where we inserted the supply feed for the diesel cook top. The stove uses the same size miniature fuel line and also just sips fuel.
You can follow the diesel conversion story here: