The data center room is the basic infrastructure protection of IT facilities running. The construction of room mainly includes decoration system, power distribution system, air conditioner fresh air system, lightning protection and earthing system, monitoring and management system, fire alarm system, integrated wiring system. The air conditioning system is the environment protection of the data center room running. Because a large number of network and computer equipments are stored with high density in the data center room, a lot of heat is not only produced, but the requirements on humidity, dust quantity and size in the environment are high, which put forward higher requirements for air conditioning system.

According to the classification of air conditioning application, they can be divided into two kinds of comfort air conditioning and process air conditioning, the former is mainly designed for human life and work, the latter is for the particular requirements for temperature and humidity, air cleanliness, operating conditions etc. Precision air conditioning is designed for the characteristics and environmental requirements of data center room, communications room, and belongs to process air conditioning.

To sum up, the environment of room is required to be stable and reliable, and specific precision air conditioning can be adopted to achieve this goal. Although comfort air conditioning units reduce the initial investment, they are unable to ensure the constant temperature and humidity, air cleanliness and ventilation in the room.

Air supply of room air conditioning system in data center is divided into two ways, room air supply and cabinet close range air supply. The latter is mainly used for high heat density cabinet refrigeration, and the former applies to the conventional environment of a single cabinet heat density less than 10KW. Air supply airflow organization in room include under-floor air supply, air supply on the hood and duct air supply. Under-floor air supply is the most important way among them with the characteristics of cooling efficiency, ease of installation and clean.

The cool air from air conditioning in the room flows into the space under static floor forming a big static pressure box under the floor. The cool air will be delivered to the front of the server cabinet by the hole-floor, inhalation by server equipment through cabinet mesh door. The hot air discharged by the cabinet will be naturally replaced by the cool air or delivered to the air outlet at the top of air conditioning through channel ceiling, air duct completing a refrigeration cycle.

Figure Downflow distribution of precision air conditioning

The cabinets will be arranged as face-to-face and back-to-back to form the hot and cold aisles. You can set ventilation floor with enough holes with large ventilation rate in the cold channel side of the cabinet. The floor ventilation rate can be adjusted according to the different heat load, or fix the ventilation floor location. It will not place ventilation floor in the hot channel side of the cabinet.

In order to ensure the cabinet temperature and humidity of the proximal and distal air conditioners is uniform, reduce wind resistance under the floor and improve the cooling efficiency, usually, the following measures can be taken:

1）Improve the height of floor placed from 300mm to 400 or even 600 to 1000mm;

2）The layout of electrical wiring is adjusted as the upper alignment, dedicated to be plenum box under the floor;

3）To close cold aisle or hot aisle to effectively cut off from the hot and cold air to prevent air short-circuit;

Figure Closed Airflow Organization of Cold Aisle

4）To increase the air containment fittings, you can increase the air supply refrigeration to 10KW high power density within the cabinet, such as floor ADU. Floor ADU is with function of forced air blowing, containing the unit floor outlet of cabinets, high porosity, and strong wind capacity for the down air distribution system, which can improve the air volume of individual floor vents to solve individual high density cabinets with wind.