SEER Rating: Is Bigger Always Better?

By Randy Arthur

President, Arthur Air Conditioning 

Smart consumers know that air conditioning systems’ efficiency is measured by Seasonal Energy Efficiency Ratio, or SEER. Every model is labeled with its SEER level, and the U.S. government now requires that no air conditioner be sold with a lower SEER than 13. (The rating is the number of BTUs of cooling output per hour divided by the total electric energy input in watt-hours under a specific set of seasonal conditions.) 

Models from five to 10 years old are rated at 9 or lower, and cost a lot more in electricity to run than the more energy-efficient 13 or 14. There are units rated as high as 19. Should you automatically choose the highest rating you can buy? Maybe or maybe not. 

Certainly the highest-rated models use less electricity to cool the same number of cubic feet of your home or business. But they are more complex in design, with more moving parts and more that can go wrong. They may require repairs more than a workhorse 13 SEER unit that will run for many trouble-free years with only routine preventive maintenance, according to Consumer Reports website. Trust only the most experienced, certified technicians to install any unit, and sign up for preventive maintenance every six months the day your new unit is installed. 

Regardless of rating, it’s the actual field conditions that set the true SEER rating of any unit, not the laboratory where it was tested. Your HVAC contractor should take these four conditions into account to make sure your new unit delivers at the efficiency you have paid for:

		Airflow: Are ducts too small, or laid out to restrict air flow? Are grilles the right size? Does the air handler match the other equipment?
		Charge: Is enough refrigerant being forced into the system? Systems with longer lines tend to be much more severely undercharged than systems with shorter lines. Ask your tech to explain why the longest line in your installation is the right size.
		Tight Ducts: If your ducts leak at the seams, you are cooling your attic.
		Size: Oversized equipment is not better; it will run for shorter periods and leave too much humidity in your indoor air. Uncomfortable hot spots can occur, and residents will reset the thermostat frequently, which is inefficient and can lead to maintenance problems.

 Be sure your licensed air conditioner installer understands which SEER rating is best for you, your budget and your home. As one of your East Lake neighbors, I’ll be happy to give you a second opinion on your air conditioning needs.