I installed 1 12k Pioneer 120v unit several years ago. Stilled used the rv bedroom factory unit. When the bedroom unit died I added the second. It is a 240v unit. That is all the cassettes offer. I choice this this due to no wall in bedroom to put a wall unit in. I really do like the cassette better though. I did put it on a transformer to run it on 120v. I can run both units, lights, tv on my 2500 watt inverter generator. They are very efficient. I agree there are higher seer units now. I second Signature Solar units. We have no problem cooling our 40" Teton now. We did with the factory units. We do use the furnace some. We like the hot heat. I have installed 4500 watt of solar, that finished, 2 6500 watt inverters, 21kwh lithium battery pak. Have not wired in inverters to ac yet. Work in progress. Should be able to run entire unit with no utility. My goal anyway. Not possible with traditional rv acs.