EER (Energy Efficiency Ratio) measures cooling efficiency at a single fixed outdoor condition (95°F). Unlike SEER, which averages across a typical cooling season, EER tells you how the unit performs at peak heat. EER2 is the updated version with slightly stricter testing protocols.
For Colorado homes that experience 95°F+ afternoons in July and August, EER is a meaningful number. A unit with a high SEER but poor EER will run inefficiently during peak heat — which is exactly when you need it most.
Typical EER values
- 10-11 EER — baseline / older units
- 12-13 EER2 — common in modern 16 SEER2 systems
- 14+ EER2 — high-performance, variable-speed
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Right Way Mechanical is a family-owned HVAC contractor serving Wheat Ridge, Arvada, west Denver, and the Colorado foothills.