I went to do a quarterly maintenance, change filters, clean cond. coils, etc.
When I showed up a woman started complaing her space wasn't cold enough. I checked the thermostat and it read 76f in the space. It also read that the fan was in auto and the system was in auto. I set the desired temp to 70f and went to the air-handler. By the way this is a 3/4 ton split system, air-handler in a closet on fourth floor and cond. coil on roof top. The unit was running when I approached it. The fan any way. I checked the suction and discharge lines by hand, they felt normal. I opened the unit, the evap. coil was clean, all wiring seemed to be in place. I went to the roof top and the compressor and cond. fan were running. So I checked the Delta T at the air handler. I had a return air temp of 72-74f and a supply air temp of 59-63f. But the space wasn't cooling. The temp at the supply grill was 72f. I then cleaned the cond. coil with nu-brite coil cleaner and changed the return air filter with a pleated filter. I checked the space one more time immediately after I did this and still no change. Unfortunately I had to leave but will be returning tomorrow to finish the maintenance. I did not put my gauges on the unit or check for super heat and subcooling, will do tomorrow. Any suggestions?, sorry for the long explanation, thought the more info I gave the less questions I would receive instead of answers.