Difference Between Computer Room AC Units and General-Purpose AC Units
Computer rooms have strict requirements for temperature, humidity, and cleanliness. Therefore, a dedicated air conditioning system for computer rooms differs greatly in design from traditional comfort air conditioning systems, and can be seen in the following five aspects:
1. Traditional comfort air conditioning systems are mainly designed for people, with a small air supply volume and a large enthalpy difference in the air supply. Cooling and dehumidification occur simultaneously. However, more than 90% of the total heat in a computer room comes from sensible heat, including the heat generated by equipment itself, lighting, heat conduction through walls, ceilings, windows, floors, solar radiation heat, infiltration air and fresh air heat. The moisture generated by these heat sources is small. Therefore, the use of comfort air conditioning systems will inevitably lead to a relative humidity that is too low in the computer room, causing the accumulation of static electricity on the surface of the internal circuit components of the equipment, resulting in equipment damage, and interfering with data transmission and storage. At the same time, since 40% to 60% of the refrigeration capacity is consumed in dehumidification, the actual cooling capacity of the cooling equipment is greatly reduced, increasing energy consumption.
Dedicated air conditioning systems for computer rooms use strict control of the evaporator's evaporation pressure and increased air supply volume to make the surface temperature of the evaporator higher than the air dew point temperature without dehumidification. All the cooling capacity is used for cooling, which improves work efficiency and reduces humidity loss (large air supply volume, small enthalpy difference in air supply).
2. Comfort air conditioning systems have a small air supply volume and low air velocity, and can only circulate local air flow in the air supply direction, which cannot form a whole air flow circulation in the computer room. This results in uneven cooling in the computer room, with temperature differences in different areas. The temperature in the air supply direction is low, while other areas are high. The heat generated by the equipment due to different placement positions accumulates locally, leading to equipment overheating and damage.
Dedicated air conditioning systems for computer rooms have a large air supply volume and a high air exchange rate (usually 30 to 60 times/hour). A whole air flow circulation can be formed in the entire computer room, so that all equipment in the computer room can be cooled evenly.
3. Due to the small air supply volume and low air exchange rate of traditional comfort air conditioning systems, the air in the computer room cannot ensure a sufficiently high flow rate to bring dust back to the filter, which results in sedimentation within the equipment and has a negative impact on the equipment itself. In addition, the filtration performance of general comfort air conditioning units is poor and cannot meet the purification requirements of computers.
Dedicated air conditioning systems for computer rooms have a large air supply volume and good air circulation. They also have specialized air filters that can effectively filter out dust in the air in a timely and efficient manner, thereby maintaining the cleanliness of the computer room.
4. Because most of the electronic devices in the computer room run continuously for long periods of time, the specialized air conditioning system for the computer room is required to be designed for high load and continuous operation throughout the year, while maintaining extremely high reliability. Comfort air conditioning systems are difficult to meet these requirements, especially in winter. Computer rooms, due to their good sealing and many heat-generating devices, still require the normal operation of the air conditioning unit for cooling. At this time, the general comfort air conditioning system is difficult to operate normally due to the low outdoor condensing pressure. The specialized air conditioning system for the computer room can still ensure normal refrigeration cycle operation through a controllable outdoor condenser.
5. The specialized air conditioning system for the computer room generally comes equipped with a dedicated humidification system, high-efficiency dehumidification system, and electric heating compensation system. Through a microprocessor, it can accurately control the temperature and humidity inside the computer room based on data feedback from various sensors. Comfort air conditioning systems generally do not have a humidification system, can only control temperature with lower precision, and have difficulty controlling humidity, which cannot meet the needs of the computer room equipment.
In summary, there are significant differences in product design between specialized air conditioning systems for computer rooms and comfort air conditioning systems. They are designed for different purposes and cannot be used interchangeably. Computer rooms must use specialized air conditioning systems. Many industries in China, such as finance, postal and telecommunications, television stations, oil exploration, printing, scientific research, and power have widely adopted them, which has improved the reliability and operating economy of computer, network, and communication systems in the computer room.