Abstract
Indices for rating operating efficiency in equipment have existed for some time, but the need for an accurate index based on actual operating conditions has recently been felt. The annual performance factor (APF) has been stipulated as a new efficiency index for office-oriented air-cooled packaged air conditioners, but no index yet exists for air conditioners in data centers that provide cooling year-round. This paper presents a detailed analysis of actual operating conditions of data-center air conditioners and proposes a new efficiency evaluation index for large-scale air conditioners in data centers.
