I have both. They are on the small end, as far as these things go.
The propane unit is about twenty years old, but I don’t really use it much. I did use it , along with some tarps to improvise a garage, of sorts, to change a heater core on my truck at my cabin in the dead of winter. Worked great.
I also pressed it into service before I got the hanging heater in the shop. The shop was well insulated and the fumes were objectionable after a while without cracking the door.
The kerosene heater is even older, but I just got it from a friend who was cleaning out his garage.
I have been using it in my shop lean to while installing conduit and electric service. The shed is 16’x50’ with a 16’ ceiling on the building side.
The fumes aren’t objectionable, but, remember that the soffit is not sealed, and the roof vents into the main shop attic.
No way will the heater bring the entire shed to temperature, but I was able to work in single digit temperatures, after a fashion.
I also aimed it at the metal clad wall to thaw frozen water pipes in the shop bathroom. (What idiot woul put water pipes in an exterior wall?)
I buy the kerosene at my propane/fuel oil distributor’s terminal for $4.00/gallon. The unit has a tag they says number 1 heating oil is ok, but I haven’t tried it, although I probably would if I expected to use it on a regular basis. None of the regular gas stations carry kerosene any more.
Both do the job. Main advantage of the propane unit is the fuel is less messy to handle. My units are small enough that they don’t have wheels. So the kerosene unit is hard to handle with a full tank (I’m old). The propane unit is lighter, or at least easier to handle.
