Small RV furnace for cab heat.........

[jenkinsph]

The heater output can be changed incrementally depending on the drill size for the jet. I would suspect the most pleasant scenario in a small space is to have a low output that is a constant or near constant run. A simple thermostat without the mercury bulb can then control the cycles without constant starting and stopping the furnace. FWIW a small truck camper rv furnace which is more compact and lower output might have been a better choice as it will warm up a much larger space in a few minutes. Overheating the cab will likely be the big issue.

 

[buickanddeere]

Exhaust heat exchanger as used in small air cooled air craft. No extra fuel and instant heat.

 

[CCWKen]

While you guys are working on getting heat, I'm trying to figure out where to mount an air conditioning compressor and condenser. :confused3: Not much call for heaters down here. If we want more heat, we open a door. Winter runs about the first two or three weeks in January. The rest of the time, it's AC.

BuickandDeere has a good idea with the heat exchanger if you have an air cooled engine. The old VWs used it and it worked pretty good. The problem is that they can get bulky.

 

[linrick1]

Made some more progress on the heater project. Cut the holes for the furnace output, exhaust and gas supply, welded up the body panels and hinge, primed the body and framework and painted the framework black. I'll paint the body Steiner red when I'm certain that I'm finished drilling or welding. I picked up a spring/snap action thermostat, and as soon as I can remove it from it's nasty brown mounting will try this first. I'm not sure how the vibration and motion of the machine will effect its performance but it is here, it was free and it might even work. Next up is the tank mount and regulator/supply line, cutting the hole in the cab, and running the wiring and ductwork. As far as finding a unit with a lower output that would suit this purpose, they are available but impossible to find used and are far beyond what my budget allows new. The Atwood unit I am using has the lowest BTU output of their entire lineup so finding something smaller and affordable would be difficult at best. As a former aircraft mechanic, I am aware of exhaust heat exchangers and their effectiveness, but dismissed this approach for a couple of reasons - I don't feel comfortable fabricating my own, having one made would be prohibitively expensive, and the ductwork required would look way too trailer for my tastes. Here are some pics of the progress to date, thanks for the input and interest, Rick

 

[linrick1]

Made a little more progress on the heater today. Cut the hole through the back of the cab and test fit the bracket/enclosure assembly and duct work, as well as measured for the propane tank mount. Went a little long with the intake shrouding on the enclosure, overhangs the side of the cab by about 1 1/2" but I don't believe it will be an issue. Still have to fabricate the tank mount, get a regulator and hose, and then wire it up but it's coming along. Thanks for the input and interest, Rick

 

[Travelover]

Be sure to post a picture of you blowing snow in your bathing suit. :laughing:

 

[chim]

Are you using 100% outside air rather than recirculating air from the cab? If so, does the heater give a "delta T" in the spec?

 

[tman1020]

Nice work so far.thats going to be toasty Probably won't be a problem but I would add a co2 detector just in case and get a good bumper guard around that gas bottle.

 

[4570Man]

Does this machine have an oil cooler? If so it should provide enough heat.

 

[buickanddeere]

100% outside air will use more LP but have left fogging than a unit which recirculates inside air.