Effect of installation faults on the performance of a split air conditioner.

The study analyzed the effect of common installation faults on the cooling performance of a residential, split air conditioner installed in a single-family, slab-on-grade house. We considered five climatic regions in the United States from hot/humid to cold. Through seasonal simulations of the house/air conditioner system, the study found that duct leakage, refrigerant undercharge, undersized refrigerant expansion valve, low indoor airflow, and air conditioner oversizing with non-oversized ductwork have the most potential for causing significant performance degradation and increased seasonal energy consumption. Seasonal energy use can significantly increase even more when the homeowner lowers the thermostat setting to remove excessive indoor humidity caused by certain installation faults.