Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I don't have my gas prices handy at the moment, but a 1960s model is probably 60% efficient and my new one is 95% efficient. I also have my thermostat lower now. But I spent about $8k*, so how many months/years will that take to pay back?

(*That's for a higher$ unit and fully installed with the AC unit and exhaust moved to a different side of the house. If you are motivated, you could probably cut that bill in half.)

There was a comfort cost (opportunity cost in economics 101?), the old unit wasn't comfortable and LOUD. The air was dry or soggy in the winter (I had to disable the built-in humidifier so itchy scratchy dry) and in the summer when the AC did work, it was very loud and the house would also yo-yo from hot to cold. I dealt with that old crappy system for 9 years.