SEER Ratings: What They Mean and Why They’re Important

Energy efficiency is an important consideration when buying any new HVAC equipment. When shopping for a new air conditioner or any other equipment, you’ll see that every model is rated in terms of energy efficiency. For air conditioners and most other cooling equipment, this is expressed in terms of SEER, or Seasonal Energy Efficiency Ratio. If you’re like most people, you might be confused about exactly what these SEER numbers mean. With this in mind, here is a full overview of the SEER rating system and what these numbers can tell you.

The SEER Rating System Explained

The SEER rating system was created to measure and to compare the overall energy efficiency of cooling equipment over the course of an entire cooling season. This system is currently used for almost every type of cooling equipment, including central AC units, heat pumps, and ductless mini-splits. The only exception is window air conditioners, which are rated in terms of EER (Energy Efficiency Ratio).

The main difference is that SEER is basically an average of how well the unit performs in a variety of different conditions whereas EER is more of a snapshot of the maximum efficiency level. This differentiation is important because air conditioners and other cooling equipment will work more or less efficiently based on the outdoor temperature and humidity level. As a result, it is necessary to estimate the average efficiency over the course of the summer to accurately rate the equipment.

To calculate SEER, the equipment is subjected to tests that simulate the typical conditions it might experience throughout the summer. Specifically, the equipment is tested in temperatures ranging from 60 to 100 degrees and also in various humidity levels. Following these tests, researchers take the total BTUs of cooling that the unit produces and divide this number by the amount of energy the unit used over the course of one cooling season.

Still, this number doesn’t really tell you anything on its own. Instead, it is simply a way to measure and to compare the efficiency of different units to see how well they perform. Some people find it helpful to think about SEER in the same way as you would the fuel efficiency of a vehicle. In both cases, tests are run to determine the average efficiency.

Just because a vehicle is rated at 35 miles per gallon doesn’t mean it will always achieve this level of efficiency in real life because conditions can either increase or decrease this number. The same is also true for SEER since the AC will generally perform more efficiently in cooler temperatures and less efficiently when the weather is much hotter or more humid.

Most central AC units and heat pumps range from 14 SEER to 22 SEER although some models go as high as 27 SEER. The average for ductless AC units is around 20 SEER, but some of these models go above 30 SEER.

The higher the SEER rating, the less energy the unit will use. Still, as you might expect, those units with much higher SEER ratings also tend to come with much bigger price tags. For this reason, the choice between units often comes down to a compromise between efficiency and price. Specifically, you’ll usually want to calculate how much money you’ll save on energy costs by using a higher rated unit compared to how much more the unit costs.

Using Seer to Calculate Potential Energy Savings

Although SEER numbers don’t really mean anything on their own, they do allow you to compare different models and to determine how much energy you can save by opting for a higher rated unit. Specifically, the numbers can be used to calculate the average amount of energy the unit will use per hour. This is done by dividing the BTUs the unit produces divided by SEER.

For instance, let’s say you need a 36,000 BTU air conditioner and want to compare the difference in energy usage between a 14 SEER and a 20 SEER unit. Based on this calculation, the 14 SEER unit would use an average of 2,570 watts of electricity per hour whereas the 20 SEER unit would only use 1,800 watts to produce the same amount of cooling.

The average AC unit runs for approximately 1,000 hours during the course of a cooling system. This means that the 14 SEER unit would use 2,570 kilowatt-hours of electricity during the summer, and the 20 SEER unit would use 1,800 kWh. Based on the nationwide average electricity price of 14 cents per kilowatt-hour, the 20 SEER unit would reduce your yearly cooling costs by around $108 per year compared to the 14 SEER unit. This means you could end up saving more than $1,500 over the lifetime of the air conditioner by opting for the more efficient model.

This type of calculation is extremely useful since it allows you to determine whether the additional energy savings from the more efficient unit will offset the increased price. There are also charts available online from the Department of Energy that allow you to instantly calculate savings based on different SEER ratings.

Minimum Efficiency Standards

The U.S. Department of Energy (DOE) has set minimum efficiency standards for all new air conditioners and heat pumps. This policy was originally established as part of the National Appliance Energy Conservation Act of 1987. At that time, all new equipment had to be at least 10 SEER.

The minimum efficiency standards have been updated several times since then, with the most recent update occurring in 2015. Since then, all new heat pumps and air conditioners installed in California and the southern U.S. must be at least 14 SEER, but 13 SEER is the minimum for the northern part of the country. The DOE has already announced that the minimum requirements will be increasing beginning in 2023. From that point, all new equipment must be at least 15 SEER for California and the southern U.S. and at least 14 SEER for all northern states.

It is important to note that just because 14 SEER is the minimum required by law doesn’t mean that these lower rated units are a bad choice. Prior to 2006, the minimum for all parts of the country was only 10 SEER. This means that if your current air conditioner was installed before this, even a 14 SEER AC could still drastically reduce your cooling costs. In this case, upgrading from your old 10 SEER unit to a new 14 SEER model should result in annual energy savings of approximately 30%.

Trusted Air Conditioning Experts

If you’re in the market for a new air conditioner, the experts at Oak Island Heating and Air Conditioning are always here to help. We are located in San Marcos, CA and have been providing professional cooling and heating services to customers throughout the San Diego area for nearly 25 years. Our highly trained HVAC technicians can handle all types of repairs, maintenance, and installations, and we work on all makes and models of equipment.

We also specialize in indoor air quality and offer numerous solutions to help clean and condition the air inside your home, including air purifiers, dehumidifiers, air scrubbers, and more. If you have any questions about AC installation or our range of other services, contact Oak Island Heating and Air Conditioning today!

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