Why is it recommended to add gravel fill under the pad of a condensing unit?

Adding gravel fill under the pad of a condensing unit is recommended primarily to prevent settling of the ground. This practice is crucial because a stable and level surface ensures that the unit operates efficiently and effectively over its lifespan. If the ground beneath the unit settles unevenly, it can lead to misalignment and potential damage to the unit. Moreover, proper leveling supports the integrity of the refrigerant and electrical components, which is vital for safety and performance.

While enhancing cooling efficiency, increasing airflow, and reducing vibration are important aspects of condensing unit installation and operation, those do not directly correlate with the primary function of gravel fill, which is to stabilize the pad and prevent settling.