professor95
did this 10 years ago to his fiver
he took the window A/C guts out of its case,(no breaks in wiring or tubing,,must be done carefully) and installed it inside the box/pan of an old roof top unit, that was non-functional
he gutted the old roof top unit to install the new smaller A/C parts
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/21943313/print/true.cfm