When looking for the right air conditioner for your space, you’re likely to come across some ratings like Seasonal Energy Efficiency Ratio (SEER) and Energy Efficiency Ratio (EER). What do these ratings mean, and how do you make sense of them? Keep reading to find out more about these important ratios, what they measure, and how you can use them to select the best air conditioner for you.
- What is SEER?
- So, What's EER Then?
- How Do You Calculate EER?
- Do These Ratings Matter?
- Comparing Products
What is SEER?
The most common way to measure the efficiency of an air conditioner is the Seasonal Energy Efficiency Ratio (SEER), which measures how efficiently an air conditioner operates over an entire season. When comparing SEER and the Energy Efficiency ratio, the difference lies in the “S”. Since SEER is based on a measurement for an entire season, the SEER rating is tested and calculated at a variety of outside temperatures ranging from 65 to 104 degrees Fahrenheit.
The calculation is designed to provide a measure of efficiency specific to climates in the middle of the United States. Additionally, SEER is more commonly associated with central air conditioners.
So, What’s EER Then?
The Energy Efficiency Ratio, or EER for short, is a standardized measurement of the energy efficiency of an air conditioner. When comparing ratings, the higher an air conditioner’s EER, the more efficient it is. What’s important to remember is that EER measures an air conditioner’s efficiency at a single operating temperature, specifically how efficient it is when the outdoor temperature is 95 degrees F.
EER is a useful piece of information when comparing room air conditioners like portable, window, through-the-wall, ductless mini-split, and packaged terminal (PTAC) air conditioners.
How Do You Calculate EER?
Calculating an air conditioner’s EER is a more streamlined process than for SEER. The equation can be viewed as:
Cooling Capacity (Maximum BTUs)
Maximum Cooling Wattage
So, if you have a 24,000 BTU air conditioner with a 1,920-watt cooling capacity, EER would equal:
24,000 BTUS
1,920 Watts
EER = 12.5
Do These Ratings Really Matter?
Both of these ratings provide an essential piece of information to purchasers of air conditioners. Energy Guide labels must be attached in a visible place on all new air conditioners. When you’re looking at the label, there’s going to be a couple of pieces of information that you’ll want to take note of.
- Estimated Yearly Energy Cost: This tells you how much you can expect the air conditioner to cost to operate per year. The cost is determined by comparing the unit with models of similar capacity and is based on the national average electricity cost.
- Appropriate Ratio: If you’re purchasing a room air conditioner, you should see the EER listed on the label. For central air conditioner units, the SEER will be displayed.
- Energy Star: An Energy Star seal will appear if the air conditioner has been independently verified to meet rigorous efficiency standards. Products with the seal are some of the most cost-effective air conditioners on the market.
Compare Similar Products
When it comes to using EER and SEER ratings to compare products, it’s important to remember that comparing one air conditioner’s EER to another’s SEER won’t provide you with any relevant information. You’ll want to examine the EER for an air conditioner against the EER for another air conditioner or SEER vs. SEER to get the most accurate knowledge.
In Summary
Seasonal Energy Efficiency Ratio (SEER) measures how efficiently an air conditioner operates over an entire season, while the Energy Efficiency Ratio (EER) is a standardized measurement of the efficiency of an air conditioner. The higher either ratio is, the more efficient the unit is.
For more information about air conditioners, be sure to check out our article about the different types of room air conditioners. If you still aren’t sure which air conditioner is best for you or how to compare them, give one of our product experts a call at 1-800-934-9194. We’d be happy to walk you through the process.
