SEER ratings, Mini Splits, and my AC system

As summer descends upon us, many homeowners turn their attention to their AC units. If you live in a older home this may be a source of great concern. Utility costs suddenly go up and comfort levels can go down. What can be done? New systems can be very costly and picking the right system can be harder than shopping for a car and cost almost as much.



Seer ratings or seasonal energy efficiency ratio indicates the relative amount of energy needed to provide a specific cooling output. Basically the higher the SEER rating the more efficient the unit. Starting in 2015 the DOE (Department of Energy) mandated that all new homes have at least a 14 SEER rating. This included the Southeast region of the US only. A typical 20+ year old home has a rating of 10 or less.

Professional AC providers are more than happy to sell you a 20+ SEER rated unit. These can be very costly. My practical advice for homeowners considering an upgrade is to not spend the bank on the latest and greatest unit, especially if you've never done any energy efficiency updates. (Additional insulation, radiant barriers, etc.) Consider going with a 14 SEER unit, which brings you up to current Code requirements and does not require any special thermostats.


Another popular upgrade is the mini split. This is a ductless air conditioner that consists of a wall-mounted indoor unit combined with an outside compressor. They are popular in hotels and can provide additional cooling to a hot room or easy add on to an addition. These are very efficient systems. Consider that the energy lost in the duct work can be as high as 25%.


These units can help if you just want to keep one room cool and keep the rest of the house at a warmer temperature. For example; I like it cooler when I sleep, but I hate the idea that the whole house has to be cooled as well. A mini split in the master bedroom is the solution. I can keep the rest of the house at 79 while the master is a crisp 68!


So, if you electric bills are a nightmare and your system is old and inefficient, consider getting a new system with at least a 14 SEER rating. If your electric bills are reasonable and your system is working, but you're hot in one room consider a mini split. Either choice will bring down your utility costs and keep you comfortable during the dogs days of summer.

- Michael Magna