Should You Coat the Evaporator as Well as the Condenser?

Why the condenser comes first

The condenser takes the full outdoor atmosphere — salt, dust and pollution — pulled through it by the fan. It is where coastal corrosion shows first.

Why evaporators corrode too

The evaporator is wet for most of its running hours. In humid climates or with outdoor air, that water film carries salt and pollutants; in some buildings, organic acids from indoor materials attack its copper tubes.

Drainage matters

An evaporator coating must be thin and fully cured so condensate still drains freely and the film does not soften when wet.

What this means for your project

List both coils in the enquiry and say whether the indoor unit handles outdoor air. For most coastal projects the outdoor coils are essential; the indoor coils depend on climate and building use.