How is the efficiency of cooling systems typically measured?

The efficiency of cooling systems is commonly measured using the Energy Efficiency Ratio (EER). EER is defined as the ratio of the cooling capacity of the air conditioning unit, measured in British Thermal Units (BTUs), to the power input, measured in watts. It represents how effectively a cooling system operates at a specific set of conditions, typically at a steady state (usually at 95°F outdoor temperature). A higher EER indicates a more efficient cooling system, allowing users to understand energy costs and environmental impacts associated with operation.

While other metrics exist, such as the Seasonal Energy Efficiency Ratio (SEER) and the Coefficient of Performance (COP), their applications are slightly different. SEER measures efficiency over a typical cooling season and accounts for varying operational conditions, while COP is primarily used for heating systems, representing the ratio of useful heating or cooling provided to the work required. The Integrated Energy Ratio (IER) accounts for various performance factors over the lifetime of the system but is not as routinely referenced for standard efficiency comparisons.

Thus, EER is the specific and conventional metric for quantifying the efficiency of cooling systems directly, aligning well with HVAC practices.