What is the seasonal energy efficiency ratio (SEER)?

The seasonal energy efficiency ratio (SEER) is a measurement used to rate the efficiency of air conditioners and heat pumps. In the United States, it is defined as the cooling output in British thermal units divided by the total electrical energy input in watt-hours over a typical cooling season. Higher SEER ratings indicate greater energy efficiency for the device. A testing protocol update in 2023 introduced SEER2 to more accurately account for duct-related energy use, while European legislation uses a different standardized measure known as ESEER.

What we know

• The SEER rating of an air conditioner is calculated by dividing its cooling output during a typical cooling season by the total electric energy input over the same period. [2]
• In the United States, SEER is defined under AHRI standard 210/240 as the ratio of cooling in British thermal units to energy consumed in watt-hours, and is controlled by a trade association. [2, 3]
• A revised testing protocol implemented in 2023 produces smaller numbers identified in documentation as SEER2 measurements, which more accurately account for energy used when pushing cooled air through ducts. [2]
• European legislation defines SEER using reference annual cooling demand divided by annual electricity consumption for cooling, utilizing SI units and region-specific conditions. [2]

Still open

• Because European and U.S. standards use different units, load conditions, outdoor temperatures, and weightings, the resulting numbers are not directly comparable.

Where to go next

• whenHow does SEER2 change air conditioner testing?
• compared withWhat is the European seasonal energy efficiency ratio?
• the bigger pictureHow is the coefficient of performance calculated for heat pumps?
• what caused itWhat role does the AHRI play in HVAC standards?
• an unexpected connectionHow does annual fuel utilization efficiency measure furnace heating?

Sources

• [1]seasonal energy efficiency ratio (Wikidata Q3798224) · CC0 1.0
• [2]Seasonal energy efficiency ratio · CC BY-SA 4.0
• [3]European seasonal energy efficiency ratio · CC BY-SA 4.0
• [4]Coefficient of performance · CC BY-SA 4.0
• [5]Annual fuel utilization efficiency · CC BY-SA 4.0