Does anyone have experience heating a woodworking shop with a Rinnai type direct vent propane heater? I'm a bit concerned with how well it would tolerate all of the saw dust in the shop. Seems as though the filter would clog up quickly. I suppose if we mounted it in an easy to access location, we might be able to live with the frequent filter cleanings (assuming she remembers to do it). We have one in a room above our garage that works well, but that is a much clener environment than the workshop.
It's a 24'x26' woodworking shop with 10 ft ceilings. As shops go, it's very well insulated & sealed: 6" sprayed in foam in the walls, 8" in the ceiling, 6" in the floor (a drive-out basement underneath is my shop), double pane windows. We've been heating it "temporarily" for over 8 years now with a couple of space heaters (a 1500 watt "Milkhouse" heater and a 1500 watt oil filled radiator, a little over 5000 BTUs each.) They are a little undersized for the room, It takes forever to warm the place up if we let it get cold, but once up to temperature, those two little heaters can keep it comfortable, even when it's 0˚F out. Maybe a little cool, but good enough for working in. In a pinch, I bring in "Big Buddy" portable propane heater to warm thing up quickly. The Big Buddy has no thermostat nd puts a lot of moisture into the room, so is not a good longer-term solution). These heaters have thermostats, but no scale on them, and the settings are not repeatable (A setting that gets us 55˚ one time is significantly off the next time.)
Judging by the fact that the 10-11,000 BTUs we have now from the space heater is undersized but tolerable, I don't think we need a very large capacity heater.
We're looking for a good long term solution. Some of what we are looking for:
- Tolerates sawdust without needing to be constantly cleaning filters (occasionally is fine, but if she has to do it every day, thatprobably won't happen)
- If a combustion type heater, must be vented outside.
- A thermostat that actually works
- The ability to set a temperature below 50˚F. We generally leave it in the high 40s when not in use. We could live with a bit higher if we had to, but we really want to keep our energy use down
- Electric or propane fueled (No kerosene or fuel oil, since nothing else we have runs on that.)
- Will run unattended for extended periods (we may not be in it for a week or more).
- Ability to run when electric power is down is a plus, though not mandatory. We can fire up a generator or bring in the portable propane heater if needed for an extended outage.
We considered a heat pump, since they are so efficient, would also provide AC in the summer, and there would be no need to site another fuel tank. A few concerns with that: (1) I have yet to find one that will allow a heating setpoint below about 55˚F. Not sure we really want to keep it that warm all winter long. (2) They do not seem at all tolerant of dirty/high sawdust environments, though I'm not sure about this. (3) The heavy electrical draw would make it tough to keep things above freezing during an extended power outage (though we could fire up the Big Buddy, if we have to.)
I've seen inexpensive ceiling mount propane heaters in some people's garages and shops. Wondering how well they do in a dusty environment. Do they make designs if these that the combustion air and by products are vented outside?
