Definition
Energy Efficiency Ratio — a measure of cooling efficiency at a specific high temperature. Useful for comparing performance on the hottest days.
Why this matters for your home
EER measures cooling efficiency at a single steady condition — typically 95°F outdoors — rather than averaged across a season like SEER2. Because it reflects performance on peak-heat days, it's a useful number for judging how a system holds up in extreme conditions.
For most Minnesota homeowners SEER2 is the headline efficiency figure, but EER matters if you run heavy cooling during heat waves. We help you read both ratings together so you're comparing equipment on the conditions your home actually sees, not just a lab average.