为了降低数据中心空调设施的能耗，作者开发了一种高效风冷式空调机组。在中低温室外空气温度条件下提高压缩机效率和扩大低压比操作区域（考虑全年冷却）可以列为其特点。除了最初的压缩循环外，空调还可作为泵循环，其开发目标是进一步降低能耗。具体而言，泵循环是将低温室外空气从室外机（间接室外机）的热交换器引入冷却液循环的系统- 空气冷却法），并用泵将冷空气输送至室内。通过使用泵循环，在室外空气温度较低期间，无需运行压缩机即可进行冷却，从而降低能耗。与传统的机房空调相比，日本札幌开发的新空调使用的能源减少了约54%，纽约减少了约50%。引用:德克萨斯州达拉斯ASHRAE Transactions第119卷第1部分。

The authors have developed a high-efficiency air-cooled package air conditioner for the purpose of reducing energy consumption in air-conditioning facilities at data centers. Improvements in the compressor efficiency in mid-to-low outdoor air temperature conditions and an expansion of the low-pressure ratio operating area, which takes into consideration year-round cooling, can be listed as its features. The air conditioner, which also serves as a pump cycle in addition to the original compression cycle, was developed with the target of additional reduction of energy consumption. Specifically, the pump cycle is the system of taking the low-temperature outdoor air into a coolant cycle from the heat exchanger in the outdoor unit (indirect outdoor-air cooling method), and transporting cold into the room with a pump. By also using a pump cycle, cooling can be performed without operating the compressor during periods of low outdoor air temperature, resulting in a reduction in energy consumption. Compared to the conventional computer-room air conditioner, the new air conditioner developed uses about 54% less energy in Sapporo in Japan and about 50% less in New York.