With one AC in the garage and one in the bedroom all centrally ducted together, I have no problem keeping any part of the Fuzion as cold as I want to in 100 degree ambient temps. In my opinion, heating the garage area is where the toy haulers are lacking. Our garage AC unit has the heat strip in it which works fine in 50 deg weather, but isn't a huge help when it is freezing out. The furnace only has one duct to the garage which doesn't receive much flow because all the other ducts are closer to the source and bleed off all the pressure. If I block the bathroom vent, I can heat the garage satisfactorily. Our last trip out in late October we saw night temps in the low 30s. We had a small electric heater in the garage and were able to maintain 70+ with little effort throughout the trailer.