SEER vs SEER2: What’s the Difference and Why It Matters for Your AC

If you’re thinking about replacing your air conditioner, you’ve likely come across the terms SEER and SEER2. These ratings are used to measure energy efficiency, and directly impact how much you spend on energy when cooling your home. With SEER2 being the new standard measurement, it’s important to understand the difference and what to look for when researching new AC systems.

What Is a SEER Rating?

SEER stands for “Seasonal Energy Efficiency Ratio.” This ratio tells you how efficiently your air conditioner operates over a normal cooling season. The higher the number means the more efficient the system is.
For example:

• A 13 SEER system is considered outdated by today’s standards in most regions.
• A 15 or 16 SEER system is more in line with modern efficiency levels.
• Higher ratings offer more energy savings over time.

Many homeowners look up SEER rating calculators or charts to understand the potential SEER rating savings between systems. A basic rule of thumb is: the higher the SEER, the lower your energy bills, especially in warmer climates.

SEER2 vs SEER

Starting in 2023, SEER2 replaced SEER as the national efficiency standard. SEER2 uses updated testing procedures that more accurately reflect how systems perform once installed in real homes; not just in a lab. Here are the key differences between SEER vs SEER2:

• SEER was based on ideal testing conditions
• SEER2 accounts for external factors like ductwork resistance and realworld airflow

Because of the testing differences, SEER2 ratings are slightly lower than SEER and give a more accurate depiction of the everyday system efficiency. So if you’re comparing SEER vs SEER2, a 15 SEER2 unit is more efficient than a 15 SEER rating unit tested under the older method.

What Is a “Good” SEER2 Rating?

A good rating for one home might not be ideal for another. Factors like the climate, how often the AC is ran, and how long you plan to stay in your home can influence your home’s ideal SEER2 rating. In general:

• A 14.3 SEER2 is a strong starting point for most homes.
• Higher ratings can lead to better long-term savings, especially in hotter climates.

If you’re looking at mini split SEER ratings you’ll often see higher SEER rating since ductless setups are typically more efficient.

How to Find Your Current AC’s SEER Rating

Most systems display their rating on the yellow EnergyGuide label on the outside of the unit. If it’s missing or unreadable you can also:

• Check your unit’s model number and look it up online
• Look at your system’s user manual or paperwork
• Ask your HVAC technician

It’s common for homeowners to wonder how to find the SEER rating on an AC unit because it is not always listed in obvious places. Likely, if your unit is older than 10 years, you will find that the systems available today have higher SEER ratings.

What About EER Ratings?

While SEER measures seasonal performance, EER (Energy Efficiency Ratio) measures a system’s efficiency at one set temperature. It’s commonly used to gauge performance during extreme heat. An excellent EER or EER2 rating is typically around 12 or higher. When evaluating AC units, typically, the SEER2 rating is more important; however, if you live in a hot and dry climate the EER rating can provide a bigger picture of the unit's peak performance potential.

Choosing Your Home’s Perfect AC System

If you’re comparing options or just want a better understanding of what’s installed inside of your home, knowing the difference between SEER vs SEER2 matters. SEER2 is the current standard, and the rating helps homeowners make informed decisions when upgrading their cooling systems. If you are not sure which system is right for your space, Mint Home is happy to help. Just provide a few details about your home's size and layout to get an instant quote– we'll help you find the top-rated system that fits your comfort needs.