Which measurement indicates the efficiency of an HVAC system in converting energy to heating or cooling?

The Seasonal Energy Efficiency Ratio (SEER) is a crucial measurement used to evaluate the efficiency of an HVAC system, particularly air conditioning systems, in converting energy into cooling over a typical cooling season. This ratio indicates how effectively a system utilizes electrical energy, as it assesses the total cooling output, measured in BTUs, divided by the total electrical energy input, measured in watt-hours. A higher SEER value signifies greater efficiency, meaning the system provides more cooling per unit of electricity consumed, which is beneficial for energy savings and lower utility bills.

While other options relate to HVAC systems, they measure different aspects. Cubic Feet per Minute (CFM) measures airflow rather than efficiency. The British Thermal Unit (BTU) quantifies energy but does not convey efficiency. Annual Fuel Utilization Efficiency (AFUE) is a measure used for heating systems that indicates how efficiently a furnace converts fuel into usable heat over a year, but it specifically relates to heating rather than cooling. Thus, SEER is the most relevant measurement for understanding an HVAC system's overall efficiency in energy conversion for cooling purposes.