I have a 2 yr old double wide with approx 2000 sq ft and a 4 ton ac unit. I had some problems with it freezing up and called an ac repairman. After 2 to 3 trips he finally found that cat hair was passing through the filters I used and had clogged the coils. He cleaned that out and I've been using higher quality filters and changing them 2 times a month. However my ac won't lower the temperature below 78 degrees. He said the freon was not low either. I live in a very small town with only a local man to repair the AC. I'm wondering if he knows what he is doing or if there is something else I can do. My AC bill this past month was $575 and for that amount I expect to be cool. I'm getting desperate for a solution. Please help.

4 ton for 2000 ft. is plenty. However, what has been the ambient temp? Does he temp go down at night? Any tree shading or full sun? Make sure all the underneath piping is insulated and connected.

You probably have ruined the compressor since it froze up. When a unit freezes up it is due to clogged coils which must be cleaned with coil cleaner and a pressure washer. When unit freezes up the compressor tries to pump liquid and bends the reed valves. When this happens the only remedy is to replace the compressor and clean the coils and blower very well. (Did you clean the blower, too?) Cleaning the blower is just as important as cleaning the coils because 1/16" of dirt in cups of blower fan blades causes a loss of 30% airflow. Once the compressor is replaced it should cool again if your duct work is tight. If the unit is under 5 years old the compressor is covered under warranty, but there is a charge like $150 to replace compressor. You have to remove compressor and write down model and serial number to ac unit and take it to dealer for a replacement, but lines must be welded shut. You need a mechanic to do this, obviously. (Having a receipt for purchase of AC unit will help greatly, but it is not needed on one two years old, only when it is borderline. You will be covered from manufacture date without receipt.) DrTom4444