Window units are not rated in SEER. They are rated in EER.
Central air conditioners are rated in both. There is a difference.
EER is a rating determined by a single standard condition, which SEER ratings are determined with multiple conditions, including conditions where it is cooler and the units operate more efficiently.
As a very rough figure, 13 SEER is roughly 11.5(+/- 5 depending on the system) EER in the standard split-system central air setups.
Usually the window AC units that are energy star that you can find on Craigslist are around 10.7 EER, this is around the 12-12.5 SEER range. The Energy Star standards changed about 2 or 3 years ago, but before that, the standards on the smaller units was around 10.7 EER.
Compared to the window air conditioners from the 70's and 80's that most older apartments still have installed today, the new energy star units are a significant improvement.
I think that the newest units out today that are roughly a 13 SEER or close to it are pretty good for a unit the size of a large luggage carry-on. These things have small coils in relation to their output and have their outlets in close proximity to their inlets.
I was actually disappointed when I saw non-inverter mini-splits with only 13 SEER, it seems with a ductless system that 15+ SEER should be close to automatic with large coils and no ductwork.
|