What are the basic components and working principles of an HVAC system? What are the main system types?

1. The subsystems of the HVAC system mainly include: heating system, ventilation system and air conditioning system.

2. Its working principle has the following steps: first, after the air comes in, in addition to introducing fresh air, the air can be cooled, and then filtered. After the filtering, several major features are added: The first is to add an electronic dust collector, which can mainly capture very small particles of dust.

Generally speaking, it can capture dust of one micron, and most of the dust within this range is bacteria, viruses, smoke, or odors, so it can be filtered out; in addition, it will add a Humidification equipment, this humidifier can create room humidification to a relative humidity of about 40%.

3. According to the purpose of use, it can be classified into comfort air conditioners and process air conditioners.

Comfort air conditioning - requires suitable temperature, comfortable environment, no strict requirements on temperature and humidity adjustment accuracy, and is used in housing, offices, theaters, shopping malls, stadiums, automobiles, ships, aircraft, etc.

Technical air conditioners - have certain requirements for temperature and humidity adjustment accuracy, and also have higher requirements for air cleanliness. Used in electronic device production workshops, precision instrument production workshops, computer rooms, biological laboratories, etc.

According to the equipment layout, it can be classified into centralized central air conditioning, semi-centralized air conditioning, and local air conditioning.

Extended information:

The evolution process of HVAC:

The most fundamental goal of the HVAC system is to control the ambient temperature to meet people's needs Environmental comfort and some technological requirements.

In early HVAC systems, constant flow hydraulic systems were generally used to adjust the ambient temperature of the target area through step-by-step control of the air volume of the terminal equipment.

For example, a three-speed switch is used to adjust the air volume of the fan coil and the air volume is adjusted through a variable air volume air-conditioning box. This kind of adjustment is simple, rough and decentralized, and there is no need to adjust the hydraulic system after the system is initially debugged.

With the continuous improvement of people's requirements for environmental comfort and energy-saving awareness, this adjustment can no longer meet the requirements. So people began to use variable flow hydraulic systems and variable air volume systems to continuously adjust the water volume or air volume of the system through electric regulating valves or air valve actuators to achieve precise control of the ambient temperature.

The electric regulating valve can be connected to various sensors, transmitters and controllers to form a decentralized control system, or it can be connected to the building control system to form a central control system for decentralized control and centralized management. This improves the system's ability to regulate ambient temperature.

However, in some variable flow systems with large system load fluctuations, since multiple electric control valves work at the same time, changes in the working status of any one electric control valve will have an impact on other electric control valves. The electric control valve itself has poor anti-interference ability, which causes the entire system to be unstable, the ability to control the ambient temperature decreases, and the adjustment accuracy decreases.

Therefore, in some current large-scale variable-flow central air-conditioning water systems, a new type of regulating valve with strong anti-interference ability-dynamic balancing electric valve is increasingly widely used.

At the same time, a new comprehensive balanced hydraulic system is being adopted by more and more large-scale variable flow water systems because of its high efficiency, stability and energy saving.

Baidu Encyclopedia-HVAC