We purchased two a/c units for use in an apartment building for a customer of ours. One unit worked fine. The other unit had a broken fan blade upon arrival and just hummed when we started it. This was an upper apartment with a couple with a baby. We didn't have time for the authorized repair dealer ordered the new blade and repaired it so we purchased a 3rd unit. We checked the box for damage  and started it up before we installed it. Same thing. Just hummed and fan not turning. We ended up ordering a 4th unit  so we would could provide cooling. Now we have two extra a/c units waiting for repair. NOT REAL HAPPY.