having the best of two worlds. I have a heat pump type air conditioner/heater that I use when I'm plugged into the dock. It can run off our generator but I can't do any charging or watermarking while I have it running. It's only a 3 Kw generator and the AC takes most of its ability. I also have a Dickerson Diesel heater which I use while underway or at anchor. I really love the AC/heater as you just set the temperature and walk away. It's clean, quite, reasonable use of amps and as I said, you just set the temperature you want.