How is SEER calculated in a heat pump system?

The Seasonal Energy Efficiency Ratio (SEER) is a critical measure for the efficiency of a heat pump system in cooling mode. It is calculated by dividing the total amount of heat extracted from the indoor air over a cooling season, measured in British Thermal Units (BTUs), by the total energy consumed, measured in watt-hours (or watts). This ratio provides a clear representation of the system's efficiency—the higher the SEER value, the more efficient the heat pump is at providing cooling.

Thus, option B correctly reflects the SEER calculation process, as it specifically addresses the relationship between the heat removed (BTUs) and the energy consumed (watts). This ratio is essential for comparing different heat pump systems and understanding their operational costs and performance efficiencies over a period.

The other options do not accurately describe the SEER calculation method. Dividing total wattage by the cooling load or energy input by output temperature does not yield the efficiency ratio in the context of seasonal performance. Additionally, using runtime hours divided by temperature difference does not align with the standard definition and calculation of SEER in HVAC systems.