Factor analysis of power-saving effects in air-side economizers for data centers

Simulations of annual reduction in power consumption based on tests of the energy-saving effect of introducing the air-side economizer (direct outside air cooling) to data centers in Japan are reported. Effects of environmental factors on energy saving are compared for air-side economizer and conventional systems that use air conditioners for cooling. When the air-side economizer is used, weather conditions affect the indoor temperature and humidity. Because outdoor air contains dust and corrosive substances that can affect ICT equipment, the introduction of outdoor air affects the indoor air quality (IAQ). We therefore investigated the effects of indoor air quality and other environmental conditions on the energy-saving effect of the air-side economizer. A background factor is that individually distributed air conditioning systems are often used for ICT equipment in Japan for their high degree of incremental expandability. Similar systems are also used in data centers with raised-floor ventilation, so the application of the air-side economizer was also investigated for its high compatibility with such systems.