You probably have ducted AC. My fwd AC has filter on the AC it self. The rear have sponge filters in the overhead of the Living room / kitchen. One on the port side one on the starboard side. Good luck.
Don & Donna Stout
E-9 Anchor Clanker
Full timers since 2010
2017 North Point 381 DLQS
2015 F-250 6.7 w/Timbrens
It is ducted. I have the whisper quiet unit. There is only one unit. Mine did not come with the optional 2nd unit in the bedroom. I intend to add the second unit before summer. I see the return inlets in the kitchen ceiling so there are foam filters under those?
I had it done and the 3rd unit easily ties into existing ductwork on my 2015 FLSA
I had one of the first 2015 FLSA and the FACTORY couldn't do it. They changed the roof design 1/2 way through the year. They also made the goose neck shorter and the basement compartment larger with side swing doors instead of top swing.