What is the central air conditioning system?

What is the central air conditioning system?

A central air conditioning system is a system consisting of one or more central machines that co-ordinates a whole distribution system for all areas of the building. Central air conditioning systems use water as a refrigerant through piped water to heat exchangers to cool the air.

Central air conditioning system consists of the main parts:
CHILLER: A device that produces cold water through a pipeline system that provides heat exchangers installed in air conditioning spaces to cool the air.
FAN COIL UNITs (FCUs): These are devices located in the air conditioners (the capacity of the heat exchangers is chosen based on the required cooling capacity of the room, which are installed in different types. ), where cold water from air conditioner goes through the indoor unit to heat the room air and perform the cooling function.
Cooling tower and water pump: performs the function of releasing the thermal energy of the condenser (air conditioner) after the air conditioner performs the water cooling in the evaporator.
Piping and cold water supply system: The system distributes cold water from the central air conditioning to the FCU heat exchanger.
Cold-air distribution pipeline system: It is the cold air distribution system from the FCUs through blown mouths to the air-conditioned areas.
Electric control system: Control system control interlocks devices in the system (Air conditioner, FCU, Water pump and cooling tower)
Features of this central air conditioning system:
- Central air conditioning can be placed on the roof floor or in the basement technical room. The heat exchangers are located in the air-conditioned rooms (usually in the false ceiling and distributed in cold air). Through the air duct and ceiling fans installed in the ceiling, the cold water piping system distributed to the heat exchanger goes in the technical box and false ceiling so the system installation does not affect the connection. structure of the building.
- The cooling system is through the air duct system and the mouth blowing from the ceiling to the area of ​​the air conditioning room, so the arrangement of the mouth to ensure the diffusion of cold air in the room is complete. can be done.
- For the central system, the addition of fresh air is simple through the air duct fitting of AHU air freshener units that supply fresh air and mix with the return air of each FCU, AHU. (This is unlikely for local machines.)
- Due to the cooling system with water, during operation, the air conditioner is running smoothly and less affected by outside temperature.
- The power factor is lower than the capacity of the system, so during the operation of the air conditioner will automatically adjust the compressor capacity to ensure the minimum energy costs in the process. operating system. This significantly reduces operating costs for the entire system.
- durability and longevity (over 15 years)
- Wide range of power to choose from, the machine can be selected with the capacity suitable for the design and investment projects to expand the system easily.
At present, in the field of air conditioning there are quite a number of systems used for different purposes and architectural features. These systems can be distinguished through a number of features. However, it is possible to generalize into some basic systems:
* Water Cooling System:
- Water cooling system, condenser cooling by water.
- Water cooling system, condenser cooling by wind.
In this system includes the main equipment such as central air conditioner, heat exchanger, condenser, water pump, etc.
The cold water produced in the central air-conditioners is supplied to the heat exchangers located in the air-conditioned spaces. Here, water acts as a heat exchanger, carrying out the process of receiving heat from the environment in the room, reducing (increasing) temperature, humidity in the room. After completing this process, water circulates back to central air conditioning and continues a new cycle.
This system is suitable for conditioning requirements for different spaces with different temperature and humidity levels (in each individual space we can choose a temperature - depends on the control in that space)
Installation requirements for this system are not very high. The distance between the false ceiling and the bottom of the beam is between 100 and 200 mm is possible.
* Wind Cooling System:
- Wind cooling system, condenser cooling by water.
- The system of cooling by wind, cooling condenser by wind
In this system includes the main equipment such as central air-conditioning, channels of wind and distribution of cold wind, condenser cooling equipment ...
Unlike the first one, in this system, the central air conditioner produces cold air and supplies it to air conditioning spaces through the air ducts. Here, the cold wind acts as a heat exchanger, carrying out the process of receiving heat from the environment in the room, reducing (increasing) the temperature and humidity in the room. After completing this process, the cold air circulates back to the central air conditioning via another duct (or return directly to the engine room) and continues a new cycle.