I’m currently living in an RV managing a property and heating with two S19s one is a single board 88 chip and one is a double board 88 chip. Both 120V APW12 psu. They are at about 27 J/Th efficiency with LuxOS.
I have not had to use any propane yet and we’ve been in single digits at times. See attached costs and rewards. The propane is for comparison and price per gal is local current. I thought this might be helpful for some, with actual numbers. Feedback is always welcome.