Recently, we had a chemical washing of evaporator coils of a precision packaged unit. The reason of using chemical to wash the evaporator coils and fins is to degrease the residue oil films and stains from the coils and fins surfaces so that water condensate is able to flow to the drain properly by gravity. Otherwise the water condensate drips everywhere within the blower compartment and eventually to the underfloor.
The first step is to remove all the blower and motor assemblies from the unit. The photo above shows MD Dragon was unscrewing the mounting screws of the blower assembly at the four corners. Then the blower assemblies were removed one by one.