The energy efficiency of your HVAC equipment is always an important factor. Obviously, the more efficient your equipment is, the less money you will spend on energy costs to run it. All HVAC equipment is rated based on its energy efficiency, which allows you to easily compare different units and how much energy they use. For air conditioners, heat pumps, and ductless mini-split systems, the energy efficiency is expressed in terms of SEER, or seasonal energy efficiency ratio.
When purchasing this type of equipment, you will see that every unit lists a SEER number. Still, if you’re like most people, you probably know little to nothing about what these numbers actually mean. With this in mind, here is an overview of the SEER rating system and what these numbers mean for your HVAC equipment.
SEER Ratings Explained
The SEER system was developed by the Air Conditioning, Heating, and Refrigeration Institute as a way to measure and compare the energy efficiency and performance of cooling equipment. Seasonal energy efficiency focuses on the total amount of cooling the unit produces over the entire cooling season and how much energy it uses to produce this.
SEER is calculated by taking the total cooling output, measured in BTUs, over the season divided by how many watt-hours of electricity the unit uses over the same season. Temperatures can fluctuate quite a lot over the course of the summer, which is why it is important to look at how well the unit performs throughout an entire season instead of just on one day. When calculating SEER, the numbers are based on a constant indoor temperature and outdoor temperatures between 60 and 100 degrees.
One easy way to understand it is to think about it as you would the fuel efficiency of your car except instead of miles per gallon SEER is the amount of cooling produced per watt-hour of electricity. This comparison also helps you to understand that SEER is simply a way of expressing the maximum energy efficiency that the unit can achieve under normal conditions. This last part is important since the outside temperature and humidity level can impact how efficiently an air conditioner or heat pump functions.
Think about it this way. Just because your car can get 30 miles per gallon doesn’t mean that it always will as numerous factors can impact and decrease your fuel efficiency. The same is also true for cooling equipment. That is to say, just because an air conditioner has a certain efficiency rating doesn’t mean that it won’t use more energy at different times. Nonetheless, SEER still allows you to directly compare different cooling equipment using a standard metric in the same way that you would compare the efficiency of different vehicles.
What Is the Minimum SEER Rating?
The U.S. Department of Energy requires that all new air conditioners and heat pumps meet minimum performance standards in terms of energy efficiency. These minimums were first established by the National Appliance Energy Conservation Act of 1987 and have been updated several times since. As of the 2015 updates, the minimum SEER required by law varies depending on which part of the country you live in.
Since 2015, all new air conditioners installed in the northern United States must be at least 13 SEER. The minimum for all air conditioners in California and all other southwestern and southeastern states is 14 SEER.
These minimums are set to rise again in 2023. At that time, the minimum for air conditioners and heat pumps will be 15 SEER in the southern states and 14 SEER in the northern half of the country. The fact that the minimums will rise in 2023 means that now is a great time to consider replacing your old air conditioner. If you wait until next year, it will potentially cost more since your new unit will then need to conform to the new minimum efficiency standards.
All ductless mini-split systems and heat pumps also have a minimum efficiency requirement. As of 2015, 15 SEER is the minimum for mini-split air conditioners in all parts of the country. For heat pumps, the minimum is 14 SEER in every state. As heat pumps can also produce heat in addition to air conditioning, they also have minimum heating efficiency requirements. This is measured in terms of heating seasonal performance factor (HSPF), but that is a topic for another day.
Using SEER to Determine Energy Savings
When buying a new air conditioner or other cooling equipment, the choice usually comes down to a combination of energy efficiency and total cost. The higher the SEER rating is, the more money you will save on energy costs to cool your home. A higher SEER rating also means that the unit will cost more money than the same size of AC with a lower SEER. For this reason, most people find it important to know how much they will save in energy for a higher SEER unit compared to how much more it costs to buy.
Although 14 SEER is the minimum in California, this doesn’t necessarily mean that a 14 SEER air conditioner is a bad choice. This is especially true if your old air conditioner was installed before 2006 as the minimum back then was only 10 SEER. In this case, even going with the least efficient unit currently available will still result in fairly significant energy savings.
You can find charts from the Department of Energy that show approximate savings for each SEER value compared to a unit with the lowest available 13 SEER. Under normal conditions, upgrading from a 13 SEER to a 15 SEER will reduce your energy usage by approximately 13% while an 18 SEER unit could reduce your energy costs by more than 25%.
Most residential air conditioners range from 13 SEER to 22 SEER, but you can find central AC units that go as high as 27 SEER. Compared to a 13 SEER, a 27 SEER air conditioner could reduce your cooling costs by almost 50%. While this is great in terms of the environment, the energy savings from a much higher-rated AC will rarely cover the additional cost that you’ll pay for the more efficient unit. This makes it important to compare the costs and the savings and determine what is most important to you.
To achieve these higher SEER ratings, the more efficient air conditioners generally use a two-stage or variable-speed compressor along with a variable-speed blower fan. This allows them to function much more efficiently as the unit doesn’t always have to run at full power. These units also more efficiently remove excess humidity from the air.
Lower efficiency AC units are generally always single-stage and one speed. This means that they tend to turn on and off more frequently and also experience more problems with uneven cooling. On the other hand, these units have fewer parts, which means that there is less than can go wrong and fewer things that could need repairing.
Professional Cooling Services and More
If you’re in need of a new air conditioner, heat pump, or mini-split AC, the experts at Friar's Heating and Air are here to help. Our technicians can evaluate the size of your home and your cooling needs to ensure that you end up with the best unit for your home. We carry a range of energy-efficient equipment from top manufacturers like Trane, Goodman, and Amana, and we work on all makes of existing equipment. Our team also specializes in heating repairs, installation, and maintenance. We are located in San Diego and serve residents in most surrounding communities. For more information on SEER ratings or if you have any other questions, give us a call today.