9/22/23 Assisted Steve in an extensive cleaning. Binding area 20 ton AC system- Today Chris and I Opened up the air handler and cleaned the evaporator coil and the evaporator coil pan and drain. We used evaporator coil cleaner. and garden hose to clean. We did improve the static pressure drop across the coil. System is working at this time Evaporator coil was very dirty evaporator. The pan was full of dirt and muck.