If you’re preparing to upgrade your HVAC, you might have come across a term called a SEER rating. This rating is important because it represents the efficiency of an HVAC system and how much money and energy it will cost to run your equipment. Here’s some information about SEER ratings and why they should be an important factor when choosing a new HVAC system.

What Is an HVAC SEER Rating?

For heating, ventilation, and air conditioning (HVAC) systems, the acronym “SEER” is short for seasonal energy efficiency ratio. A SEER rating is a ratio derived by dividing the cooling system’s output during an average season by the energy used in watt-hours. The SEER rating represents how much money and energy the system uses to operate during a year.

A system that uses less energy for cooling will have a higher SEER rating since the ratio represents its maximum efficiency. However, efficiency can vary based on different conditions.

A system’s SEER ratio is calculated over a whole cooling season using a constant indoor temperature with varying external temperatures that range from 60 degrees Fahrenheit to 100 degrees Fahrenheit to simulate an average season. A system with a higher rating uses less electricity than an air conditioner with a lower SEER rating.


The SEER ratio has been updated to SEER 2. The primary difference between SEER and SEER 2 is each rating system’s testing conditions. The new rating system was designed to align with energy consumption reduction efforts.

The Department of Energy (DOE) increased the external static pressure conditions used for SEER 2 to make them closer to the static pressure in a typical residential ducted system. By contrast, the testing conditions used in SEER ratings do not properly account for how the ductwork affects the external static pressure. This means that in SEER ratios, external static pressures used often were not enough to simulate real-world conditions.

What Are the Benefits of a High SEER/SEER 2 Ratio?

Air conditioning systems with higher SEER 2 ratings come with a higher price tag than lower-rated systems. However, choosing equipment with a high SEER or SEER 2 ratio offers multiple benefits, as described below.

Greater Energy Efficiency

AC equipment with a higher SEER/SEER 2 rating will be more energy efficient than equipment with a lower rating. The minimum SEER 2 rating for air conditioners is 13.41. However, air conditioners typically have SEER 2 ratings between 13 and 21. The SEER rating represents the air conditioner’s maximum efficiency, and the efficiency of the system you choose will vary based on other factors, including your ductwork, home size, etc. Because of this variability, you should also implement other energy-saving measures to control costs.

Increased Comfort

Air conditioning systems with higher SEER 2 ratings ensure the interior comfort of the homes they cool. A highly rated system will cool more efficiently while maintaining your desired indoor air temperature.

Variable-Speed Compressor vs. Two-Stage Compressor

Lower-rated air conditioners typically have single-stage blowers. This means that an air conditioner with a low SEER 2 rating may turn on and off frequently when the weather is mild. This can lead to uneven cooling in your home. Single-stage blowers can also lead to higher levels of humidity in your home, which can make the temperature feel warmer than it is. The effective removal of humidity from the air requires your AC to run instead of turning off and on.

By contrast, AC systems with higher SEER ratings have dual-stage compressors, which means they run on high or low. Having two stages allows the compressor to reduce its energy needs in mild weather when it operates on low. When the weather is hot, the compressor will instead run at a high output to keep the temperature even and cool.

Systems with high SEER 2 ratings might have variable-speed compressors, which allow them to operate at multiple levels. This allows the energy output to be customized to maintain the interior comfort of your home. Air conditioners with variable-speed compressors blow a continuous stream of air to maintain the temperature in your home consistently while reducing the energy requirements as needed.

Smaller Carbon Footprint

A high SEER 2 rating means your system will not require as much energy to operate and will be more efficient. By choosing an air conditioning system with a higher rating, you can ensure your impact on the environment will be smaller. Your system will use less energy, and your utility costs should be lower. Some newer models also use more environmentally friendly refrigerants.

Why Does the SEER Rating of Your AC Matter?

Older systems from a decade ago had SEER ratings ranging from eight to 10, which indicates they operate less efficiently. They also require more energy and have higher utility costs. If you have an older air conditioning system, you can check its SEER rating by looking at the EnergyGuide sticker on the equipment or the paper attached to your HVAC system’s air handler. Your system’s model number will likely refer to the SEER unit. However, if you are unsure what it is, you can find the serial and model number and call the manufacturer to find out what its SEER rating is.

If you have an air conditioning system that’s 10 or more years old, replacing it could help you save 20% or more on your annual energy costs. The U.S. Department of Energy has issued new energy standards that require all air conditioners to have a minimum SEER rating of 13, but you can get a system with a SEER rating of up to 21 or more.

However, this doesn’t mean you should avoid an air conditioning system with a lower SEER 2 rating. Your home’s insulation and ductwork can affect your air conditioner’s performance. Even if you choose a system with a high SEER 2 rating, it’s still a good idea to follow other energy-saving strategies to keep your energy costs low during the summer months.

Packaged HVAC systems also use SEER ratings to indicate their maximum energy efficiency. With the large variety of systems available, it’s smart to evaluate the benefits each one might offer in terms of both the SEER rating and other features to figure out which one might work the best for you.

Talk to Our Experts

If your air conditioning system is not working as efficiently as it once did, you might be thinking about replacing it with a newer system. Consistently high utility bills, a system that constantly shuts on and off, and uneven indoor temperatures might indicate it’s time for a replacement. The SEER rating of the new system you choose will be important in terms of energy efficiency, indoor comfort, utility costs, and more. Our experienced HVAC technicians can help you understand how the various factors might affect the efficiency of your new system and help you choose the one that will best meet your needs. Call us at Aace's Heating, Air Conditioning & Swamp Coolers in Victorville, CA, today for more information about SEER ratings and HVAC installation. We also offer swamp cooler installation and maintenance, maintenance plans, and service for your air conditioning and furnace equipment.

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