The minimum SEER standards for energy efficiency of air conditioners and heat pumps are set by the U.S. Department of Energy (DOE) and one standard was applied nationwide until 2015. That’s when they switched to regional standards, dividing the country into north, south, and southwest. A higher minmum SEER rating was then required for air conditioners in the South, and higher still in the Southwest, so units manufactured to the lowest acceptable SEER standard for the north are not allowed in the other two zones, and minimum units in the South are not allowed to be sold in the Southwest. That’s the reason for the “INSTALLATION PROHIBITED IN SOUTH AND SOUTHWEST” and “INSTALLATION PROHIBITED IN SOUTHWEST” warning at the bottom of the data label at the side of some air conditioners.

    The SEER standard for heat pumps is currently the same for all three regions, so you won’t see the “INSTALLATION PROHIBITED” notice on a heat pump data label. But new regional standards are coming in 2023 and you can expect them to be nudged up, and possibly unevenly, again every few years after that. Where the prohibition for minimum SEER condenser installation applies may shift around over time and might appear on some heat pumps too. 

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  To learn more about heating and air conditioning systems, see these other blog posts:

• How can I find out the SEER of my air conditioner? 

• My air conditioner won't turn on. What's wrong? 

• How can I find out the size of my air conditioner? 

• How can I tell whether the condenser (outdoor unit) is an air conditioner or heat pump? 

• Where is the air filter for my central air conditioner and furnace? I can’t find it? 

• Does an old air conditioner use more electricity as it ages? 

• How did homes stay cool in Florida before air conditioning? 

• What is wrong with an air conditioner when the air flow out of the vents is low?

• Why has the thermostat screen gone blank? 

• Why does it take so long to cool a house when an air conditioner has been off for a while? 

• Why is my air conditioner not cooling enough? 

• What are the most common problems with wall/window air conditioners?  

• Will closing doors reduce my heating and cooling costs? 

   Visit our HEATING AND AIR CONDITIONING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.