SEER (Seasonal Energy Efficiency Ratio)

A rating measuring an air conditioner's efficiency over a cooling season.

Definition

SEER is the ratio of cooling output (in BTUs) to total electric energy input (in watt-hours) over a typical cooling season. Higher SEER = more efficient.

In plain English

US federal minimum is currently SEER 14–15 depending on region. SEER2 is the newer testing standard introduced in 2023.

Example

Upgrading from a SEER 10 unit to a SEER 18 unit can cut a home's cooling bill by ~40%.

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