To accommodate internal information systems, companies provide a separate room - a server room. It installs computers, computers, servers and other telecommunications equipment. The room has strict requirements for climatic parameters: humidity and temperature. The optimal conditions for the functioning of the equipment are provided by the installation of air conditioners. The type and capacity of the air conditioner is selected taking into account the characteristics of the server room.
Purpose of conditioning in server rooms
Server room is a room reserved for telecommunication equipment. The room is equipped with backup power, temperature and humidity sensors. The room has no windows. The operating equipment generates a huge amount of heat, and the air conditioning system is engaged in its removal. It should provide favorable conditions for the operation of servers. High temperatures and dust in the air can damage sensitive equipment. To bring indicators to normative is the task of the climatic device.
Server Room Features
Choosing air conditioning for server rooms, take into account the specifics of the premises and the basic requirements for them:
- Climatic equipment should work continuously, round the clock, 365 days a year.
- The optimum temperature is 18-25 ° C.
- Air humidity in the range from 20% to 80%. In winter, 75-80% is allowed, in summer - not higher than 65%.
- The amount of dust is up to 0.75 mg / m3, the particle size is not more than 3 microns.
- The optimum air flow rate is 0.2 m / s, fluctuations in the range up to 0.5 m / s are allowed.
- Noise level is not higher than 65 dB.
Based on the characteristics of the room, air conditioners must control the level of humidity, temperature and degree of dust.
Recommendations for choosing the type of air conditioner
Not every climate system can withstand the difficult conditions of continuous loading. It should be equipped with a dust filter, a dehumidifier, a winter kit. One option for air cooling is a server cabinet with air conditioning. The design does not require condensate drainage, the outdoor unit is compact in size. The indoor unit is installed vertically or horizontally inside the server cabinet.
Air Conditioner Requirements
When maintaining the climate in the server rooms, the uninterrupted operation of air conditioners is important. Failure and repair will leave telecommunication equipment without cooling for a long time. The requirement is ensured by the principle of rotation and redundancy. The room is installed several air conditioning systems, combined into a single network by a rotary device. If one air conditioner fails, the backup option automatically turns on.
Alternating switching on of the blocks allows balancing the load distribution and ensuring optimal climate parameters. In this mode, the equipment stops alternately for rest and maintenance.
The rotation unit helps control the conditioning of the server rooms. It automatically alternates the inclusion of work settings, if necessary, connects a backup device. The second control option is the installation of sensors, the readings of which are displayed on the computer monitor. To determine the conditions in the server room do not have to leave the workplace. All information in the form of tables and graphs is sent to a computer.Messages are accompanied by a sound signal.
Split systems
To maintain the specified parameters in the server rooms, split systems are used. High-power domestic or semi-industrial systems are installed in rooms of a small area with heat up to 10 kW. By type of installation, they are:
- Wall mounted is a universal and affordable option. Productivity 2.5-5 kW, a model is selected in which a significant length of the freon path is provided. Recommended manufacturers are Daikin, Toshiba, and Mitsubishi Electric.
- Ducted - devices are placed under a false ceiling, save space and provide efficient air exchange. Suitable for large server rooms. Ducted air conditioning delivers cold air directly to the racks.
- Column - powerful systems in the form of cabinets are installed on the floor, do not require installation.
Split systems in which winter operation is not provided are finalized by winter sets.
Precision Climate Systems
Precision air conditioners for server rooms are professional equipment. Climatic complexes have a high resource of continuous operation, allow you to maintain optimal temperature and humidity. One of the advantages of the equipment is accuracy, climatic indicators in large areas have fluctuations of not more than 1 ° C and 2%. In server rooms, cabinet and ceiling models are installed. The first differ in bulky dimensions, their power is 100 kW. Ceiling systems are less efficient (20 kW); they are installed in rooms where it is not possible to place cabinet air conditioners.
Climatic complexes are monoblock and split-type separate systems. The system is cooled in various ways: by evaporation of freon, water or air circuit. Popular manufacturers: UNIFLAIR, Blue box.
Advantages of installations:
- smooth operation;
- high power equipment;
- precise control of climate components;
- wide range of operating temperatures;
- combination with supervisory control.
Cons of precision systems:
- high price;
- noise of a monoblock design.
Chiller fan coil system
The air conditioning system uses water or a mixture of ethylene glycol as a coolant. The principle of operation is similar to installations with freon. The chiller cools the liquid circulating in the fan coil heat exchanger, passing through the radiator the air lowers the temperature.
Advantages of the system:
- high performance;
- universality;
- safe and affordable operation.
Air conditioning problems in winter
Minus outside temperature in winter leads to problems in the operation of climate control systems:
- The compressor oil viscosity increases, its properties deteriorate. At the time of start-up, friction of spare parts increases.
- Icing of the fan blades of the outdoor unit.
- The compressor oil dissolves in freon during continuous operation.
- Withdrawal of the drainage hose in order to save money is carried out on the street. At a negative temperature, the water in it freezes, forming a cork that prevents condensate drainage.
The solution to the problems is the choice of air conditioning for the server room with a winter kit. It includes:
- Cable for heating the compressor housing. Oil becomes liquid, thorny parts are excluded, resulting in quick wear. A 30-50 W heating cable is installed at the bottom of the compressor.
- Heating of the drainage is carried out by a cable, dressed on a tube.
- Fan speed controller of outdoor unit. The electronic device is installed in the fan power break. The unit controls the speed from 0 to 100%. The speed is selected according to the temperature sensor.
Selection of air conditioning by type of cooling
Depending on the size of the room and the number of servers, one of those cooling options is selected:
- Air conditioning throughout the room. The disadvantage of this method is the uneven distribution of cold air. Due to the low efficiency, the consumption of electricity increases.
- Zone cooling of cabinets installed in rows. The cooler is built into the rack or an air-conditioned server cabinet is used. Blowing air flow occurs on the grilles of the equipment or in a cold corridor. To increase the efficiency of the system allows the separation of the zone of hot and chilled air.
- Individual air conditioning with mounting a precision system on a server rack. Installation performance is used most rationally. The disadvantage of this method is that the cost of such equipment is higher than other options for climate technology.
Selection and calculation of air conditioning power
The performance of HVAC equipment is determined at the server design stage. Calculations are based on the total heat emissions of each cabinet. Indicators are taken from equipment documentation. The air conditioner power calculations for the server room take into account the special requirements for the room and equipment operating modes. The main criterion for choosing an air conditioner is cold performance. Its value should exceed the total heat release. You can use the online calculator on specialized sites. Accurate data will be required:
- area of the room;
- ceiling height;
- heat dissipation technology;
- number of staff.
Formula for self simplified calculation:
PQo + Qn + Qm, where
P is the power of the air conditioner;
Qo - heat emission of telecommunication equipment;
Qn - heat dissipation of people and auxiliary devices (uninterruptible power units, artificial lighting);
Qm - heat input to the room from the environment.
In the absence of accurate data on server cabinets, heat dissipation is considered as 30-50% of power consumption. The volume (area) of the room is also taken into account when choosing an air conditioner. After calculating the required performance, redundancy is provided.
Do not forget that an increase in the power of the air conditioning system leads to its appreciation.
