It is natural to use air conditioners for computer room projects. When choosing the air conditioner for the refrigeration system of the data center, many IT personnel in the data center thought that ordinary air conditioners can also be used for cooling the computer room, and believed that the energy efficiency of ordinary air conditioners is high, so it can be Reduce the energy consumption of the refrigeration system.
As we all know, usually 30% of the cooling load of ordinary air conditioners is to eliminate the latent heat load, and 70% is to eliminate the sensible heat load. For precision air conditioners, the situation is quite different, mainly to eliminate the sensible heat emitted by the equipment in the equipment room, the heat load emitted by the indoor staff, and the heat and humidity load of the fresh air entering the room in summer (only 5 of the total load). %). This determines that they will be different in terms of design usage, application scenarios, and functional focus.
Q1. Can the small project be replaced by a small ordinary air conditioner?
Q2. What is the essential difference between ordinary air conditioners and precision air conditioners?
1. different basic concepts
Ordinary air conditioners generally include household air conditioners, central air conditioners in residential areas, and air conditioning systems in offices and commercial office buildings. The function of this type of air conditioner is to create a good living environment for indoor air, provide people with a comfortable working and living environment, and make people in this space feel comfortable.
The precision air conditioner is designed to meet the requirements of the special process and specific environment of the precision equipment. Its purpose is to precisely control its temperature, humidity, etc. and require it to be controlled within a certain range. It is also called constant temperature and humidity air conditioner, which is characterized by large air volume and heat load Variety.
2. Product focus
Due to different design uses, the product focus will also be very different.
Ordinary air conditioners are designed to "provide people with a comfortable working and living environment". Its applicable object is people, and its application scenarios are mainly in semi-open areas where people are active: such as living rooms, bedrooms, exhibition halls, offices, etc. Ordinary air conditioners do not have the function of "constant temperature and humidity", and the temperature difference range is 1 °C. Therefore, ordinary air conditioners pay more attention to the design of comfort, low noise, low air supply and low wind speed during use.
Precision air conditioners are designed to "provide a specific operating environment with constant temperature and humidity for precision devices such as IT equipment". This is a high-precision air conditioner specially designed for computer rooms. In order to ensure good heat dissipation of computer or server chips, the application scenarios include computer rooms, laboratories, large medical equipment rooms and other high-precision fields. Its service object is related equipment that maintains the continuous operation of the computer room: such as IT equipment, power distribution system, power supply equipment, etc. The precision air conditioner has the function of "constant temperature and humidity", and the temperature difference range can be controlled at 0.1 degrees Celsius or even higher. Therefore, precision air conditioners pay more attention to the design of precise control of temperature and humidity in the equipment room and timely control of cleanliness.
3. Different control systems
Ordinary air conditioners only have a basic control system. According to their own heating and cooling needs, people operate through the infrared remote control or the smart remote control downloaded from the mobile APP. The intelligence is relatively moderate; and cooling and dehumidification can only be performed at the same time. Direction local air circulation.
Precision air conditioners have a high-precision, responsive, microprocessor-based intelligent control system that can quickly respond to changes in the external environment, thereby ensuring that environmental changes remain within the setting range required for a stable environment. For example, human-computer interaction interface, alarm protection, network monitoring and other functions.
4. Different degrees of air filtration
Ordinary air conditioners use coarse filters, which cannot remove enough dust particles. The dust will adhere to the high-efficiency chips to a large extent, which will seriously affect the service life of related components and cannot meet the purification requirements of computers. Most common air conditioners use residential-type air filters with a filtration efficiency of only 10%. This is not enough for a data center environment.
The precision air conditioner uses a high-efficiency filter, its efficiency can reach 20%~30%, and it meets the ASHRAE standard, which can filter out the dust in the air in a timely and efficient manner, which can effectively prevent the dust from adhering to the high-frequency chip and cause a short circuit due to carbonization. Improve the cleanliness, prolong the service life of related parts, and reduce operation and maintenance costs.
5. Different operating performance and cost
Common air conditioners used in most office buildings run for an average of 8 hours a day, 5 days a week, while some commercial places, such as supermarkets and shopping malls, run an average of 12 hours a day, 7 days a week. Sometimes there are environmental changes or special needs that increase the runtime. For precision air conditioners, no matter what the external environment is, most data centers require uninterrupted operation 24 hours a day, 365 days a year.
And those ordinary air conditioners with outdoor heat exchangers generally cannot operate when the external ambient temperature drops below 32°F because the pressure is too low. However, precision air conditioners operate normally at -30°F, while glycol refrigeration systems cool normally at -60°F.
Although the initial investment of precision air conditioners is basically much higher than that of ordinary air conditioners. However, the annual operating cost of ordinary air conditioners is higher than that of precision air conditioners by $243/per ton of sensible cooling capacity. This is consistent with the principle generally recognized by the industry, that is, the refrigerating capacity of 3 ton of ordinary air conditioner is equivalent to 2 ton of refrigerating capacity of precision air conditioner.
Therefore, for those small projects, in the case of sufficient funds, it is recommended to consider both the initial investment and operating costs; and for some large projects, it is still recommended to use precision air conditioners, which are designed for uninterrupted operation throughout the year. Intelligent control system, constant temperature and humidity functions, components and redundant functions, etc., will greatly improve the reliability of equipment operation, and will greatly reduce operation and maintenance costs in the later stage.