Dust, wind, and abrupt freezes put different demands on a heat pump.
Anson spends much of the year in conditions where cooling is the larger job, which is one reason a heat pump suits a home here: the same outdoor equipment handles summer air conditioning and winter heating. The harder transition comes when a cold front arrives quickly or temperatures fall to a freeze. The outdoor unit has to shift into heating operation, manage frost through defrost cycles, and bring on supplemental heat when the weather calls for it.
Those short, sharper cold spells make setup important. The equipment has to be selected for the job, refrigerant performance has to be right, electrical support has to carry the system when supplemental heat is needed, and the thermostat has to tell the equipment when to change modes. A problem in any of those parts can show up when the weather changes even if cooling seemed normal beforehand.
Dust and wind also collect around an outdoor unit over time. Restricted coil airflow makes it harder for the unit to move heat, while a poor mounting arrangement leaves the equipment less secure in windy conditions. We also look beyond the outdoor unit at the ducts. A heat pump cannot make up for major air loss or uneven airflow caused by ductwork that is not distributing conditioned air well.