Efficiencies of chillers are viewed a bit differently now than they used to be. “Before we looked at the design kW/ton of the chiller,” said Roy Hubbard, director of market development, Engineered Systems Group, York International Corp., York, PA. But it was realized that design conditions might not be the best indicator of overall performance.
Likewise on residential and light commercial equipment, EER (energy efficiency ratio) was originally used. “But EER was not representative of the entire operation of the unit,” Hubbard noted. “So something was needed to look at it from different standpoints, different parts of the year, under different loads, and so on. That’s how SEER (seasonal energy efficiency ratio) came into existence.”