When shopping around for a new air conditioner, SEER is one way to compare it to other models. This is the Seasonal Energy Efficiency Ratio, or Seasonal Energy Efficiency Rating. It is the ratio of an AC’s cooling output during an entire cooling season, divided by how much energy is used (expressed in Watt-Hours). Assuming the indoor temperature is constant, SEER is determined by a simulation of outdoor temperatures ranging from 60°F to over 100°F.
A SEER ratio identifies an HVAC unit’s maximum efficiency. Just because an air conditioner has a specific rating doesn’t mean it will always perform at that level, just as a car rated to get 25 miles per gallon on the highway won’t be as fuel efficient on city streets. Likewise, operating conditions will affect how efficient your AC is.
What Do Different SEER Ratings Mean?
The United States Department of Energy has set guidelines for minimum AC efficiency ratings. It requires all air conditioners to be rated at least SEER 13. Here is a look at some common ratings.
- SEER 13-15: A basic level usually associated with single-stage air conditioning units. They must run on the highest setting to achieve efficiency, and thus may create uneven temperatures at home and be on the noisy side.
- SEER 16-19: Provides a better level of efficiency with quieter performance. Designed to run at about 65% capacity, these units create the same results with less work, along with even cooling and dehumidification.
- SEER 20-24: The best performers, these units adjust automatically, so they can run from 25% to 100% capacity based on demand. In addition to efficiency, these variable-capacity central air conditioners create balanced temperatures, are quiet, and reliable.
Benefits of a Higher SEER Rating
The higher its SEER rating, the more expensive the AC unit. With efficiency combined with manufacturer rebates and tax credits, a homeowner can see a return on investment with a higher-end unit. SEER ratings for most air conditioners generally range up to 21 or 22. The benefits of a high SEER ratio generally come down to efficiency, which contributes to energy savings, and comfort particularly in hot climates. High-SEER air conditioners often include a two-stage or variable speed compressor and a variable-speed blower that improve performance.
What Is the Best SEER Rating for My Home?
If you live in the Southwest and Southeast regions of the U.S., you’ll want an AC system that’s at least SEER 14. In the North, you can get by with as low as SEER 13. Compared to older systems rated at around 8 or 9, even these units are somewhat efficient. Still, there are other factors that impact efficiency, including the size of your home, sunlight and shading, and the condition of your ductwork.
Calculating a SEER Rating
Most AC’s have their SEER rating listed on a label. But you can calculate it mathematically. First, find how many British thermal units (BTUs) per watt-hour your air conditioner uses in a cooling season, and then note how many watts per hour your unit uses. There are about 125 days between late spring and through the summer, equal to about 1,000 hours; therefore, multiplying the number of BTUs by 1,000 reveals how many BTUs the system uses during the season. To calculate watts used during the entire cooling season, multiply the system’s wattage per hour by 1,000. Then divide the total number of BTUs by the total watts per hour consumed—this will yield the SEER rating.
Contact Sky Heating & Air Conditioning
Specializing in installing, repairing, and maintaining many types of air conditioning systems, we can help you find an AC unit or system with the best SEER rating for your home. Schedule an appointment online or call 503-235-9083 now for assistance.