We started with one unit and now have four. We bought an 1830's 3-story house that has never had central AC. We consider installing central air but the cost was astronomical. We bought one unit to tryout and loved it so we bought 3 more. Two 10,000 btu units cool our entire 1st level. We have an 8,000 btu unit in our master bedroom and a 6,500 btu in our guest bedroom. Second level stays comfortably cool. Units are way quieter than other brands we considered and they look great. They are heavy so it's a two person job to install. I love being able to adjust each unit from my phone. Only option I would like to of had are timers on the units.