I kinda did exactly that! When we first had our steal tent it would get mighty hot. so i dissambled our(insert random chinese brand portable a/c here) for just this purpose. Being a Transit we are limited on space (and funds
) so i located the entire compressor & coil assembly under the bus and brought the output flush with the floor. Being only 11kbtu it doesn't do a lot but it would def cool the rearward portion of the bus A OK! Since then i've aquired some older coleman MachIII units that work that i will attempt the same procedure on!
Also! If you have one with a remote i just added some wire and brought the IR sensor up the wall so we could control it from bed!