What can cause a decrease in cooling efficiency in a refrigeration system?

A decrease in cooling efficiency in a refrigeration system can often be attributed to clogged air filters. When air filters are blocked, it restricts airflow to the evaporator coil, resulting in reduced airflow across the coil. This impairs the system's ability to transfer heat effectively, leading to a higher load on the compressor and ultimately causing the system to work harder to achieve the desired cooling effect.

In contrast, maintaining proper refrigerant levels is crucial for optimal performance, as insufficient or excessive refrigerant can cause inefficiencies, but this option does not directly imply a decrease in efficiency when it is maintained correctly. Accurate superheat settings ensure that the refrigerant is evaporating properly, also contributing positively to efficiency. Furthermore, low humidity levels do not inherently decrease a system’s cooling efficiency; in fact, lower humidity can sometimes improve perceived cooling by reducing moisture in the air.