There could be several causes. Check to make sure that coils and fins on condeaser unit are clean and if not shut off power to unit and wash them out or blow out with compressed air. Make sure air filters on furnace or air handler are clean. Check fins on squirrel cage blower and clean as needed.Check freon levels and pressures to make sure you don't need to add freon.Also make sure that there is insulation and it is in good condition on the suction line to condensor,Large line.I hope some of this helps you. One other thing you can check is the fins on the A-coil and clean if needed.Most people won't do this because often they are in sealed case. Good luck and thank you.

Hello, there are a few thing that can cause a Air conditioner to not cool well enough. First off the airflow should be checked, filters, evap coil to see if they are clean. Secondly the unit may have a leak which is causing your unit to loose refrigerant and therefore not cool well. Have these two areas checked out on your air conditioner.