The in dash AC will cool the complete motorhome if you open a rear vent in the coach. Even in 110 degree F temps our complete motorhome is cool using the indash AC or warm using indash heat. To make the indash heat and cooling work the air must have some place to go and if the only exit is at the other end of the rig it goes there cooling or heating every thing along the way. If you close up the coach then it just stays in the driver area. One of the hardest things to do is to get people to open a rear vent in the heat or cold..
