I just got a new window a/c 6300btu. Previously I had a 10,000 btu window a/c. When I first got it it cooled my whole apartment. Then 7 years later it started to fail this season, before I placed it in the window I did what I thought was cleaning the filter, coils and guts of the a/c. Nothing special just running water through it then I put into window. It no longer worked as it did, after that I put the thing in and out the window repeatedly cleaning to no avail. I would have to set the temp to 60 in order to feel cool air on the least brutal days. Two of the coils would freeze up going all the way back to the thin wound wires. (I know that freezing coils can be either due to needing more freon, a leak, or a crack in the coil but I never saw any leaks or any coils or wiring that looked like it was misshapen, but I thinking that if the fins were damaged then a clot could form where ever the fins were either damaged, clogged, or non existent. It made a lot of noise moreso than when I first got it, and when the compressor kicked in it was like hearing the sound and movement of a stick shift car changing gears.

O'k my question is, is this normal for all window a/c's? My new a/c (the 6300 btu a/c) which is an off brand (Generations) I was thrilled to it's performance, it was so quiet even when the compressor switched on. No humming or vibrating, I could barely tell when the compressor switched on and it cools very too. Since it's been in the window for about 3 weeks it's starting to sound more like the old a/c but not as much. It still cools well but I'm wondering if it's my imagination but I do remember and thought how quiet this a/c is compared to my old GE a/c. The new a/c was put in the window professionally using a tape measure and one of those $40 a/c supports, the a/c is drilled into the window. It did not vibrate at all, now there's some vibration when the compressor kicks on. WTH???

I have an aching suspicion the super of this building might have done something to both of them. I'm on the first floor so he could easily reach them, the 10,000 btu was even more convenient to him. Is it possible he could have put some corrosive liquid in them to make this happen? When I was cleaning the 10,000 btu I noticed in the back where the inside fins were that only in that spot the fins were brittle and easily broke off. My final attempt to try to save the a/c I bought some foaming cleanser for it and sprayed all the coils and fins but only the inside fins in the back nearest to the fan in a few spots were brittle. Could the foam had damaged those fins? If so then why wouldn't all the fins be damaged? This was a product specially for cleaning the coils in a/c's.

I just want to know if it's possible per I don't trust this man. Please don't suggest moving, I can't afford it right now.