No denying the fact that torpedo heaters are STINKY mothers! My shop generally smells like burnt K1 until early spring! However, while I have a wood stove (i love wood stoves) I do not have the room in my little cramped space to work a wood stove in, and even if I did I doubt I would. I would not want to fight the insurance company for coverage even if I could use a wood stove.
In fact, I have never heard anyone say that using a torpedo in a sealed environment is anything but unsafe. All I can figure out is the garages I have used my heater in must have been semi drafty because I have never had an issue with a sense of drowsiness or something of that nature. If breathing became an issue I think I would sense something like that in a hurry, I am asthmatic. The one thing I do prefer about the torpedo over a wood stove in particular is if I want to use an explosive or combustible chemical I can shut the torpedo down and use the substance, following it's use I either promptly leave, or open the shop and totally clear it of fumes before plugging the torpedo back in. Clearly, I could not do that with a wood stove.
If I had my way, I would have a natural gas unit hanging from the ceiling, I would love to retire my torpedo, though I am thankfull for the heat it provides on those real bone chilling days when work in the shop is a must.