Design Method and Performance Verification of Fresh Air Cooling by Using Twin Voids in Large Scale Building

Abstract

Two multi-functional voids were planned to enable total outside air cooling in the building where there is considerable internal heat generation and the cooling period is long by utilizing two multi-functional voids. The voids were designed as ventilation towers for supply air and exhaust air, and planned to install a barrier between the openings of both voids on the rooftop. Two voids were located under consideration of the regular wind direction and the effect of separation flow on the rooftop to avoid short-circuit between supply air and exhaust air. From the result of the air flow analysis using CFD and field measurement, it can be confirmed that exhaust air containing pollutant or tracer-gas from the exhaust air void do not move to the supply air void.

Using Naturally Cold Air and Snow for Data Center Air‐Conditioning and Humidity Control

“…The resulting power consumption can be readily expected to rise . Furthermore, there are many problems, including the fact that using so much underground water may cause ground subsidence in surrounding areas, assuring a constant water level continuously for the ground water may be difficult, and the water level may vary by year. Method Using Outside Air In summer the outside air is hot and cannot be used during periods when the temperature of the air blown by the air conditioning in a data center is above 18 °C. In practice, the data centers in Japan are often set up in warmer regions (Kanto and further west), and the period in which air conditioning using outside air can be implemented is short. In cold regions, the period in which outside air can be used is longer, but on the other hand, there is a period in which the air temperature is too low, and if cold outside air is used, the humidity may drop sharply due to the difference in humidity with the server room, resulting in problems such as negative effects on computers (generation of static electricity).As a result, only part of the data centers in Japan at present use outside air as a supplementary measure, and there are no examples in Japan of its use on a large scale in cold regions where the effect would be high . Method Using SnowIn cold regions, summer is a season in which the outside air becomes hot for a given period and cannot be used in air conditioning. In snowy regions in cold regions, there is a long‐standing tradition of building houses to store snow for farm products.…”

“…Method Using Outside Air In summer the outside air is hot and cannot be used during periods when the temperature of the air blown by the air conditioning in a data center is above 18 °C. In practice, the data centers in Japan are often set up in warmer regions (Kanto and further west), and the period in which air conditioning using outside air can be implemented is short. In cold regions, the period in which outside air can be used is longer, but on the other hand, there is a period in which the air temperature is too low, and if cold outside air is used, the humidity may drop sharply due to the difference in humidity with the server room, resulting in problems such as negative effects on computers (generation of static electricity).As a result, only part of the data centers in Japan at present use outside air as a supplementary measure, and there are no examples in Japan of its use on a large scale in cold regions where the effect would be high . …”

“…As a result, only part of the data centers in Japan at present use outside air as a supplementary measure, and there are no examples in Japan of its use on a large scale in cold regions where the effect would be high [6][7][8][9][10][11][12][13][14][15][16].…”