OK, I have a old 1995 travel trailer installation is poor and it has plenty of leaks. It is 40 feet long and has 2 pop outs that make it about 13 feet wide. So about 520 sq ft max. Do you think it would be cheaper to run the old roof top AC or run a window unit. I don't know how much wattage it would be to run the roof top, but I do know that the window unit will run at 1,350 watts. I live in Florida and it is parked right under the sun with no shade. Both units will keep the trailer cold, but I don't know the life left on the rooftop unit. And i want to keep the utility bills down. What is your experience and knowledge? Is their a way I can estimate? Should I go with the roof top or window ( it is a Frigidaire 15,100 BTU 11.2 EER 115V Window Air Conditioner - FFRE1533Q1 )
The water cooled AC units are outside air units.
Look at the nameplate rating on the installed unit. If it has a higher wattage than the window AC it will cost more to run. A 15,000 BTU Dometic roof mount AC currently is specified as 1,530 watts. So it runs less than 200 watts higher than your window AC. That is only about 3 cents an hour more in power cost. Running both of the units will cost you about 50 cents per hour, or $12 a day if running all the time. If you only ran one unit and added some small fans to circulate the cool air more efficiently you might find that works well enough. Do you really need to keep the trailer cold as you call it? If you keep it reasonably moderate you will get used to the temperature. It isn't necessary to have your home freezing cold.
