• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4253-4259
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• 2015

In this study, the effects of various control methods of outdoor air cooling control system on control characteristics and energy consumption in building are researched by simulation. The system analysis modelling is done by using TRNSYS program package, and the control performances with existing outdoor air cooling methods are compared with the control ones without outdoor air cooling. As a result, appropriate operating temperature conditions of outdoor air cooling system according to outdoor temperature changes are required, and the outdoor air/return air dry bulb temperature comparison control method among the control methods shows best responses in energy savings.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.7
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• pp.371-376
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• 2013

Recently, many studies related to reducing the energy consumption in data centers have been conducted. These studies have mainly focused on the air intake and exhaust system of a computer room air handling unit (CRAH) in the server room, diffuser type, suppression and discharge of the heat generated from the server, and the air-side economizer system. In this study, the energy consumption of the conventional central chilled water cooling system is compared with the energy consumption of the air-side economizer system. We also examined how changes of differential pressure by each filter have influenced energy consumption, using the power usage effectiveness (PUE). Results show that the PUE was improved, and energy consumption decreased, by applying the air-side economizer system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.4
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• pp.145-150
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• 2014

Many studies are being conducted with the aim of reducing the energy consumption in data centers, which are one of the highest consumers of energy. The use of an air-side economizer system that uses external air during intermediate and winter seasons is being considered for reducing the energy consumption of air conditioners. In this study, using the energy simulation, we evaluated the energy performance of a central chilled water cooling system and air-side economizer system in domestic data centers. Further, the cost-effectiveness of the air-side economizer was analyzed through Life-Cycle Cost Analysis. The results showed that with the use of air-side economizer systems, the energy costs increased as the applied filter grade increased; however, unlike existing central chilled water systems, it would break even within 2 years.