Congrats on the greenhouse! I had to wait 73 years before I got mine. It's been so much fun! I love going to sit inside when it's snowy and cold outside.
I think it depends mostly on your altitude. We are at 6500 ft near Silver City. We bought one, and it had a safety feature that automatically turned it off when oxygen was low. It required manual re-setting to run again. It would only run for less than 5 minutes. We now use electric for the greenhouse.
We heat our home now with a wood pellet stove. It keeps the main areas warm, and the bedrooms much cooler.
