Hey Guys, At one of my houses the electricity usage is up about 50% over previous years. This is comparing months with the same average outdoor temp and the indoor temp is about the same. The high bills also start with the seasonal a/c usage so I don't think it could be anything else in the house. Seems to me the a/c system must have taken a dive in efficiency this year. What would explain this? Coolant problem? What should I check? Filter is good. Thanks!

I have a Friedrich window unit, model SM16A30. It cools a non-insulated game room (converted garage) that is 625 sq ft and it does a great job. Even in hot summer in the upper 90s it can cool the room to 68 degrees! I am not happy with a worker that decided on his own to take the grill off the front and "service" it. I was absent from the room and when I returned I saw him fiddling with it. I bought this house and this unit has worked flawlessly for 44 years, a 1974 model. When I turned it on the next day, it ran great for hours and cooled the room but I had to leave the house for two hours and when I opened the door, yuck, horrible smell and the room was warmer than it should be. It smelled "electrical" to me. It didn't sound right, it was kind of buzzing. I don't recall if it was blowing. I immediately turned it off. I remember thinking, aw heck, it must've locked up, thinking it was the electric motor or compressor failure. I asked the worker what he did to it. He said he took off the grill and the filter that covers the front was falling apart. I guess it is a carbon filter or styrofoam? He had been cleaning the baseboards in the room and he sprayed some of the household cleaner on the filter and put it back in! I have no idea why he did that. When I took off the grill today and looked at it, the "filter" material was gone, all that is left is a plastic frame that I guess supported the filter material. If you can even buy such a filter, it should have been replaced long ago. I dont' know what you call it... the corrugated aluminum-looking material that surrounds the front coils... I did not notice much at all of the filter material inside that corrugated metal. If there was a quite a bit of the filter material when he put it in there, it went somewhere. I turned on the A/C to see if it would run at all and it did but I was afraid to run it very long. It seemed to be putting out cool air but the fan speed was not nearly as strong. I decided to shut it down. I am not as mechanically-minded as some guys, sorry for the ignorance, but any idea what went wrong? Anything I can do short of calling an A/C repairman? Do you think this might be salvageable? What can I do? Can filters be bought for a 1974 model?