Understanding SEER vs SEER2 Ratings A Guide for Arizona Homeowners

As an Arizona homeowner, staying informed about energy efficiency ratings is crucial, especially with the recent introduction of the SEER2 rating system. Understanding the differences between SEER and SEER2 can help you make more informed decisions when it comes to purchasing or upgrading your HVAC system. In this blog post, we’ll delve into the intricacies of both ratings, explaining what they mean and how they can impact your home’s energy consumption and comfort levels.

What is SEER?

SEER stands for Seasonal Energy Efficiency Ratio. It measures the efficiency of an air conditioning unit over an entire cooling season, calculated by dividing the total cooling output (measured in BTUs) by the total energy input (measured in watt-hours). In simpler terms, SEER indicates how effectively an air conditioner converts electricity into cooling power.

Understanding SEER Ratings:

  • Higher SEER = Greater Efficiency: A higher SEER rating means that the air conditioner is more energy-efficient. For example, a unit with a SEER rating of 16 is more efficient than one with a SEER rating of 14.
  • Energy Savings: Upgrading to a higher SEER-rated system can lead to significant energy savings over time, resulting in lower electricity bills.
  • Environmental Impact: Higher SEER ratings generally indicate lower greenhouse gas emissions, contributing to a greener environment.

Introducing SEER2:

SEER2 is an enhanced version of the SEER rating system, designed to provide homeowners with more accurate information about their air conditioning system’s energy efficiency. Unlike SEER, which measures efficiency at a single outdoor temperature (usually 95°F), SEER2 takes into account a wider range of outdoor temperatures to better reflect real-world conditions.

Key Differences Between SEER and SEER2:

  • Temperature Variability: While SEER is based on a fixed outdoor temperature, SEER2 considers multiple outdoor temperatures, providing a more comprehensive assessment of the system’s efficiency.
  • Dynamic Performance: SEER2 accounts for fluctuations in outdoor temperature, giving homeowners a clearer picture of how their air conditioner will perform in different weather conditions.
  • Improved Accuracy: By incorporating a broader range of temperatures, SEER2 offers a more accurate representation of a system’s energy efficiency, helping homeowners make better-informed decisions.

Benefits of SEER2 for Arizona Homeowners:

  • Better Performance Prediction:  In Arizona’s hot climate, where temperatures can vary significantly throughout the day, SEER2 provides more accurate predictions of how an air conditioning system will perform under real-world conditions.
  • Optimized Energy Savings: With SEER2, homeowners can select air conditioning systems that are specifically designed to deliver optimal energy savings in Arizona’s unique climate.
  • Enhanced Comfort:  By choosing a system with a higher SEER2 rating, homeowners can enjoy improved comfort levels, even during extreme heat waves.


Understanding the differences between SEER and SEER2 ratings is essential for Arizona homeowners looking to invest in energy-efficient air conditioning systems. While SEER provides a baseline measure of efficiency, SEER2 offers a more nuanced and accurate assessment, particularly in regions with extreme temperature variations like Arizona. By choosing a system with a high SEER2 rating, homeowners can enjoy improved energy savings, environmental sustainability, and overall comfort in their homes. When considering HVAC upgrades or replacements, consulting with a trusted HVAC professional can help you navigate the complexities of SEER and SEER2 ratings to make the best choice for your home and budget.