Red rock dust coating return boots and coil fins
Why it happens here
Wind moves fine red dust across the whole community, and standard filters only catch part of it. The rest settles in return boots and on the evaporator coil. It is worse on the ridge and mesa where exposure is highest.
Our approach
We vacuum the return side before agitating anything, then clean the coil with coil cleaner and a low-pressure rinse. We also check your MERV rating and recommend an upgrade if the system can handle it. Most homes here move up two filter grades.