Study on free cooling systems for data centers in Japan

A free cooling system is one effective solution for reducing the power consumption of air conditioning systems. In recent years, free cooling systems have gained the spotlight in Japan, so we have conducted a survey and simulation-based estimation toward their introduction. The estimation results have shown that the water-side economizer requires doubling the capacity of the cooling tower and consideration of the installation space and cost, while the air-side economizer increases the humidifying power, which requires the relaxation of indoor humidity specifications. According to the simulation-based comparison results, the package-type air-conditioning unit with an expanded scope of low pressure ratio control has the lowest power consumption per year.