Although it’s important to consult the RV AC manual for step-by-step installation details, here are a few general pointers. 

First, you need to remove the old AC unit — or, if your RV came without one, you’ll need to create a roof vent to hold your AC unit. If you’re removing an existing unit, be sure to get all the screws out and carefully scrape away the caulking or sealant; to ensure you’ll get just as tight and waterproof a fit with your new unit!

You’ll also need to ensure that the existing wiring matches your AC’s requirements, or install proper new wiring if you’re starting from scratch.