1. The subsystems of 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 treatment, several features are added: first, an electronic dust collector is added, which can mainly capture the dust of non-small particles.

Generally speaking, it can capture a micron of dust, and most of the dust is bacteria, viruses, soot or peculiar smell, so it can be filtered out; In addition, a humidifier will be added, which can create room humidification to about 40% relative humidity.

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

Comfort air conditioning - it requires appropriate temperature and comfortable environment, and has no strict requirements on the adjustment accuracy of temperature and humidity. It is used in housing, offices, cinemas, shopping malls, gymnasiums, automobiles, ships, aircraft, etc.

Process air conditioning - there are certain requirements for the regulation accuracy of temperature and humidity, and there are also high requirements for the cleanliness of the air. It is used in electronic device production workshop, precision instrument production workshop, computer room, biological laboratory, etc.

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