We had neighbors with only a front living room air, unit wired for a 2nd in bedroom. They constantly complained about just the 1 not cooling enough. Ordered a 2nd to be installed in bedroom after having it in to the rv place and check 2 or 3 times and always returned saying - working fine. Son installed 2nd A/C and decided to clean and check front one. Baffles in vent were closing off the vent most of the way and the cooled air was barely coming thru. He readjusted the baffles and guess what ---- 2nd A/C not even needed now .