How is the energy efficiency ratio (EER) calculated?

The energy efficiency ratio (EER) is calculated by measuring the cooling output of a refrigeration or air conditioning system in British Thermal Units (BTUs) and dividing that figure by the power input in watts consumed by the system. This ratio provides a straightforward assessment of the system's efficiency, allowing operators to understand how effectively the unit converts energy into cooling. A higher EER indicates a more efficient system, meaning it produces more cooling output for each watt of energy consumed. This calculation is particularly valuable when comparing different systems or assessing the performance of a unit under specific conditions.

The other options do not directly pertain to the calculation of EER. For example, measuring operational cycles does not reflect energy efficiency, and analyzing temperature differences across components or monitoring refrigerant flow rates, while important for overall system performance, do not yield the EER metric itself.