Arrived to perform Ac tune up. Customer has no concerns Set thermostat call for cooling Observe indoor unit, air filter, condensate system, coils and performed temperature readings Observe out door unit, service coils, electrical compartment, motors, refrigerate lines The customer has 2 indoor units and 1 split central. I observed that the indoor units were dirty and I tried to clean them, but the dust is attached and it is difficult to remove. Recommended to wash all 2 units