Manabu Kishita

Aisle-capping method for airflow design in data centers

This report describes cold aisle capping and hot aisle capping methods, one of the airflow design techniques for data centers and telecommunications equipment rooms where high heat density equipments are installed in racks. In both cold and hot aisle capping, the aisles are enclosed by sidewalls at the end of the aisle and by a ceiling over the aisle. These are expected to provide effects of improving hot spots, which are caused by the exhaust air flowing into the cold aisle, and to provide an energy-saving effect by reducing the energy loss, which is caused by mixing of the supply air and the exhaust air of the IT equipment. This report presents the results of an experiment on the effects of improving the hot spots, energy-saving, and temperature-rise suppression during air-conditioner shutdown in the case that each method is applied. A practical example of installing the cold aisle capping in an existing equipment room is also described.

Improving the efficiency of cooling systems in data centers considering equipment characteristics

Internet data centers are helping to expand the network society throughout the world. These data centers require air conditioning to operate, and raising the efficiency of their cooling systems can have significant benefits such as the prevention of equipment failure and the saving of energy as well as improved cost performance. A data center in which much heat-generating equipment has been installed produces a large amount of heat, and achieving a balance between cooling power and fan driving power holds the key to greater efficiency. This study consisted of: 1) full-scale mockup experiments that consider the ventilation of even heat-generating equipment installed in racks; and 2) efficiency evaluation and intake-temperature evaluation based on measurement results for fixed heat-generating equipment using ventilation volume and interequipment gap area as parameters. The results of these evaluations revealed that intake temperature could be predicted when varying these two parameters.

Relationship between the reliability of a Data-center air-conditioning system and the air-conditioning power supply

This report describes reliability of a Data-center air conditioning system, especially in the viewpoint of the relationship between the reliability and the air conditioning power supply. We examined the system reliability including the air-conditioning power supply in detail, and proposed a new factor for evaluating the reliability of the power configuration of the air conditioning system in this report.