Understanding EER2 Ratings: What They Mean for Your Air Conditioner

Shopping for a new air conditioner can be overwhelming, especially when you encounter technical terms like “EER2 rating.” But knowing what these terms mean can help you make a smarter, more informed choice. HVAC.com breaks down what an EER2 rating is, how it’s measured, and why choosing a unit with a higher EER2 could save you money and keep you cooler.

What Is an EER2 Rating?

The EER2 (Energy Efficiency Ratio 2) rating measures how efficiently an air conditioner or heat pump cools your space on a very hot day – typically at 95°F outdoors, 80°F indoors, and 50% humidity. This updated version of the traditional EER rating offers a more accurate measure of real-world performance by accounting for higher external static pressures during testing.

The formula is simple: the unit’s cooling capacity (in BTUs) divided by its power input (in watts). A higher EER2 rating means better efficiency, which translates to lower electricity bills. For example, an AC with an EER2 of 12 uses less energy than one rated at 10 while providing the same cooling effect.

EER2 vs. SEER2: What’s the Difference?

Both EER2 and SEER2 measure an air conditioner's efficiency but focus on different conditions. While the EER2 evaluates performance under peak cooling conditions, typically at 95°F, SEER2 (Seasonal Energy Efficiency Ratio) measures efficiency over an entire cooling season, with temperatures ranging from 65°F to 104°F.

If you live in an area with mild summers, SEER2 is likely more relevant, as air conditioners rarely operate at peak capacity. However, if you live in a hot climate such as Phoenix that experiences intense heat regularly, EER2 provides a more accurate measure of your AC’s efficiency on the hottest days.

Who Can Benefit from a Higher EER2 Air Conditioner?

Here are some groups who would particularly benefit from a higher EER2 air conditioner:

1. Homeowners in Hot Climates: If you live in a region with high summer temperatures, such as Florida or Texas, your air conditioner likely works overtime. A unit with a higher EER2 rating not only keeps you cool and comfortable but also provides better humidity control and improved cooling performance – without inflating your energy bills.
2. Businesses with Large Spaces: Offices, retail stores, and restaurants need consistent cooling to ensure customer and employee comfort and protect equipment. A high EER2 air conditioner delivers enhanced comfort and more efficient cooling, helping to significantly reduce operational costs.
3. Environmentally Conscious Consumers: If you aim to reduce your carbon footprint, choosing an air conditioner with a higher EER2 rating is a smart move. It minimizes energy consumption, lowers greenhouse gas emissions, and provides better climate control for your space.
4. Anyone Looking to Save on Energy Bills: Even in mild climates, a high EER2 unit helps you save money – especially during the hottest months when air conditioning usage spikes – while maintaining consistent comfort and efficient humidity control.
5. New Home Builders and Renovators: If you’re building a new home or upgrading your HVAC system, investing in a high EER2 air conditioner ensures long-term savings, enhanced comfort, and improved cooling performance for years to come.