What does a SEER rating mean?

By Advanced HVAC Systems

 First off, what is a SEER rating? SEER is an acronym for Seasonal Energy Efficiency Rating.
So what does this mean to the average consumer?  Theoretically the higher the SEER the more efficient the unit. It is a metric used to measure the cooling output (BTU/hr) for each unit of energy consumed (watts).
The problem is the SEER isn't very accurate.  Units are tested for SEER at a base temperature of 82 degrees Fahrenheit. So what happens if the temperature were to rise 10 degrees? In short you will lose an equivalent ton of cooling. The capacity of the air conditioner goes down and energy consumption goes up.

SEER believe it or not is a marketing tool used to make air conditioners seem more efficient. A more accurate way to measure efficiency is the EER or Energy Efficiency Rating.
Similar to the SEER the EER is calculated by taking the total BTU's of rejected heat and dividing it by the energy used to reject that heat. The difference is EER's are measured in a controlled environment (95 degrees outdoor and 80 degrees indoor) and SEER's take seasonal variables into account. Therefore values will vary depending on where the unit is tested.

That being said. A higher SEER is still better, but may not be worth the additional cost depending on your climate. Annual savings probably wont justify the higher cost of the higher seer unit.

Advanced HVAC Systems