Understanding the Evolution of Air Conditioner Efficiency Ratings: From SEER to SEER2

For many years, air conditioners were rated using two primary metrics: SEER and EER. SEER, which stands for Seasonal Energy Efficiency Ratio, and EER, the Energy Efficiency Rating, both serve to measure an air conditioner’s efficiency, but they do so in different ways.

SEER vs. EER: The Basics

SEER (Seasonal Energy Efficiency Ratio) is a rating system that evaluates how efficiently an air conditioning unit converts electricity into cooling over a range of outdoor temperatures that simulate a typical summer season. This means that SEER takes into account varying temperatures, providing a comprehensive efficiency measure over the course of a summer.

EER (Energy Efficiency Rating), on the other hand, measures efficiency at a single outdoor temperature, specifically 95 degrees Fahrenheit. This provides a snapshot of how well the unit performs under peak heat conditions.

Historically, units might achieve high SEER ratings by performing well at moderate temperatures (around 70-75 degrees) but might not be as efficient in higher temperatures. Despite this, the overall SEER rating would remain high due to the rating system’s averaging over a range of temperatures.

The Shift to SEER2 and EER2

In January 2023, a significant change occurred in how these efficiency ratings are calculated. The U.S. government introduced SEER2 and EER2 ratings. The main reason for this change is the recognition that most duct systems in American homes are not adequately designed. Many homes suffer from insufficient supply and return ductwork, leading to increased external static pressure in duct systems.

Under the previous SEER and EER ratings, the efficiency calculations did not realistically reflect these common duct system inadequacies. The new SEER2 and EER2 ratings account for higher external static pressure, providing a more accurate efficiency measure under typical real-world conditions.

Impact of the New Ratings

With the introduction of SEER2 and EER2, many air conditioning units have been re-evaluated. For example, a unit that was previously rated at 20 SEER might now be rated at 18 SEER2, even though the unit itself has not changed. This adjustment better reflects the unit’s performance under the more realistic conditions accounted for in the new testing standards.

Additionally, lower-end efficiency models that previously met SEER standards may no longer comply with SEER2 criteria. This has led manufacturers to retool their product lines. For instance, Rheem undertook a significant overhaul of their lower and mid-range efficiency models to meet the new requirements, although their high-end models largely met the new standards with only minimal adjustments.

In Conclusion

The shift from SEER to SEER2 and from EER to EER2 represents a move towards more accurate and realistic efficiency ratings for air conditioners. These new standards ensure that ratings better reflect the actual performance of units in typical home environments, considering the common issue of inadequate ductwork. As a result, consumers can now make more informed decisions based on these updated efficiency ratings.

At Bryan’s Heating & Air Conditioning, Inc., we’re committed to providing fast, reliable, and professional HVAC services to ensure your home or business stays comfortable year-round.

Call (316) 755-2447 or message us to get the expert assistance you need. Our team is ready to help with all your heating and cooling needs.