Our low profile, roof mount A/C unit with heat is a Coleman 9,200 BTU “Polar Cub”. We love it and so do our customers. It requires 110v power so you must have shore power or generator power to turn it on. Those in the northwest or in climates where A/C is not as important as heat, you might consider a motorized vent in the ceiling plus our catalytic propane heater. The motorized (12v) vent is called a Fantastic Fan and it forces air into the camper or out of the camper. With windows open it creates a lot of air flow inside the camper. The propane heater is a radiant heat unit that works really well in the small interior of the camper. The Fantastic Fan and propane heater can both work with battery power and your camper’s propane bottle. Any time the heater is on, please have a window cracked or your vent open to let fresh air into the camper. The heaters should never emit LP gas, but they do gradually deplete the oxygen supply if there is no fresh air.