What is a SEER?
SEER is an acronym that stands for Seasonal Energy Efficiency Rating. It’s a benchmark of how much electricity a given A/C system uses to deliver each Btu/h of cooling power compared to another one under a standard, fixed set of rating conditions. The rating system is managed by the Department of Energy, and they decide what the testing standards are. The higher the SEER number is, the higher the score the system has received on the D.O.E. mandated efficiency tests.
What many don’t understand is that the emphasis here is on the word ”system”. And the outside unit is only one part of the cooling system. You also have the inside cooling coils (sometimes called the evaporator or A-coil). The blower system in the furnace (or air handler) is also a part of the system as far as the SEER testing goes, because the SEER rating is based on the amount of cooling produced by x outside unit and x cooling coils – using x air volume delivered by x blower system.
The blower motor in the furnace or air handler uses x amount of electricity, as does the outside unit. And the SEER rating tests are basically calculating how much total electricity the system uses to deliver its BTU of cooling. So the SEER tests are conducted with x furnace (or air handler), x outside unit, and x inside cooling coils.
There is technically no such thing as a “13 SEER” outside unit when you come right down to it. The same outside unit could end up with a higher or lower than 13 SEER score, depending on the inside coil and furnace (or air handler) being used to test it with.
To make a long story short, the SEER rating is given to a combination of typically 3 components.