Hello, My home central air is not cooling the house. The system is probably 25 years old but has worked pretty well up to now. The compressor is running, the condensor fan is running. The refridgerent pressures are 30 and 175. I opened the panel to the evaporator and the lower couple of coils on each side of the "A" coil are cold and frosted but all of the rest of the coils are barely cooler than ambient. Only the bottom 1/5 of the "A" coil is cold. The larger insulated line out of the evaporator is also barely cooler than ambient if that. Can anyone offer an opinion as to what is wrong? This site has been a great help to me. Thanks