Kianoosh M out for Warranty Install, customer called with issues that system has not been cooling well. Said the thermostat was set to 73 and system would not get down below 75 today. The high outside was 87 and sunny. Inspected thermostat controls, checked blower, coil, and outside condenser. Customer has been using fiberglass see-through filters, strongly recommend changing to pleated filters. Explained the difference and showed customer how dirt and dust is getting through the fiberglass filters into the blower and evaporator coil. Outside condenser coil was dirty from running all summer. Checked temperature split, and getting a split of 12 degrees. Could not access attic to see ductwork / insulation levels because customer has items in the way. Washed condenser as a courtesy, checked refrigerant pressures, and 9 /8 degrees subcooling. Checked temp split and got 15 degrees. Also cycled system in heating as a courtesy. System is functioning as well as it can in heating and cooling