What is the basic composition of HVAC? What are the classifications of HVAC?

With the continuous improvement of people's living standards, people pay more and more attention to the pursuit of a better and more comfortable living environment and material environment. Air conditioning is a common household appliance in people's daily life, but today, Bian Xiao wants to talk to you about HVAC. I believe many friends are not familiar with HVAC. What is the composition of HVAC? What is the working principle? Next, Bian Xiao will introduce you to HVAC. Let's have a look.

First, the basic composition of HVAC system

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

The heating system mainly includes hot water heating and steam heating. Hot water heating is more popular in buildings. Hot water heating keeps the indoor temperature by circulating heat exchange between hot water and secondary heat exchanger. The basic components of the system include: boiler, circulating pump, secondary heat exchanger, pipeline system and indoor terminal.

Ventilation refers to the process of giving people fresh air and removing exhaust gas in indoor space. The main purpose of ventilation is to ensure indoor air quality, and proper ventilation can also reduce the temperature of indoor space. Ventilation includes natural ventilation and mechanical (forced) ventilation.

Air-conditioning system is composed of many components, which can adjust the air in the building under manual control to achieve the required conditions. Its basic function is to treat the air sent into the building to a certain state, so as to eliminate the indoor residual heat and humidity and keep the temperature and humidity within the acceptable range of human body.

A complete and independent air conditioning system can be basically divided into three parts, namely: cold and heat sources and air handling equipment, air and cold and hot water transmission and distribution system, and indoor terminal equipment.

Second, the classification and basic principle of HVAC system

1. Classification by purpose of use

Comfortable air-conditioning-it requires proper temperature and comfortable environment, and there is no strict requirement on the accuracy of temperature and humidity adjustment. It is used in homes, offices, theaters, shopping malls, gymnasiums, cars, ships, planes and so on.

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

2. Classification according to equipment layout

Centralized (central) air conditioning-air treatment equipment is centralized in the central air conditioning room, and the treated air is sent to the air conditioning system of each room through air ducts. Suitable for shopping malls, supermarkets, restaurants, ships, factories and other places with large area, concentrated rooms and close heat and moisture loads in each room. The maintenance and management of the system are convenient, and the noise elimination and vibration isolation of equipment are easy to solve, but the energy consumption of fans and pumps in the transmission and distribution system of central air conditioning system is high. In Figure 8-4, if there is no local air treatment A, only centralized air treatment B is used for air conditioning, and this system is centralized.

Semi-centralized air conditioning-an air conditioning system with central air conditioning and terminal devices for handling air. The system is complex and can achieve high adjustment accuracy. Suitable for hotels, hotels, office buildings and other civil buildings with independent adjustment requirements. The energy consumption of transmission and distribution system of semi-centralized air conditioning is usually lower than that of centralized air conditioning system. Common semi-centralized air conditioning systems include fan-coil system and induced air conditioning system. In Figure 8-4, there are both local air treatment A and centralized air treatment B***, and this system is semi-centralized.

Local air conditioning-each room has its own equipment to handle air conditioning. Air conditioners can be installed directly in a room or in an adjacent room to treat air locally. Suitable for offices, computer rooms, families and other occasions with small area, scattered rooms and large difference in heat and humidity loads. Its equipment can be a single independent air conditioning unit, or a system composed of fan-coil air conditioners. The cold and hot water are supplied centrally through pipes, and the temperature of each room can be adjusted as needed. In Figure 8-4, if there is no centralized air treatment B and only local air treatment A, the system belongs to local type.

3. According to the bearing medium classification

All-air system-only sends hot and cold air to the air-conditioned area through the air duct, as shown in Figure 8-5? As shown in (a). The types of air ducts in all-air system are: single-zone air duct, multi-zone air duct, single-tube or double-tube, terminal reheat air duct, constant air volume, variable air volume system and mixed system. In a typical all-air system, fresh air and return air are mixed, processed by a refrigerant coil, and then sent into the room to heat or cool the room. In Figure 8-4, if the air conditioner only adopts centralized treatment B, it belongs to the all-air system.

Full water system-the room load is borne by the centralized supply of cold and hot water. As shown in Figure 8-5(b), the cold water circulating from the central unit is transported to the coil in the air handling unit (also called terminal equipment or fan coil) for indoor air conditioning. Heating is realized by the circulating flow of hot water in the coil. When the environment only needs cooling or heating, or heating and cooling are not carried out at the same time, two control systems can be used. The hot water required for heating is made by electric heater or boiler, and is dissipated by convection heat exchanger, kick plate radiator, finned tube radiator and standard fan coil unit. In Figure 8-4, if only refrigerant water is subjected to local air treatment A, it belongs to the all-water system.

Air-water system-part of the load in the air-conditioned room is borne by centralized air, and other loads enter the air-conditioned room with water as the medium to reprocess the air.

Direct evaporation unit system-also known as refrigerant air conditioning system, the load of air-conditioned room is directly borne by refrigerant, and the evaporator (or condenser) of refrigeration system directly absorbs (or releases) heat from air-conditioned room, as shown in Figure 8-5? (d) as shown in the figure. The device consists of air handling equipment (air cooler, air heater, humidifier, filter, etc.). ), ventilator and refrigeration equipment (refrigeration compressor, throttle mechanism, etc. ). In Figure 8-4, only the local heat exchange of refrigerant A works, and the refrigerant is a liquid refrigerant, so it belongs to the direct evaporation system.

The above is the knowledge about HVAC compiled by Bian Xiao. I believe you have a better understanding of HVAC after reading it. Bian Xiao believes that HVAC has brought greater convenience to our lives and is a very good product. Friends who need to buy air conditioners may wish to try HVAC, but Bian Xiao reminds everyone to pay attention to the quality of HVAC when purchasing, and try to buy them in regular stores to prevent buying fake and shoddy products.

Tubatu Online provides you with "every decoration quotation, 1-4 local decoration companies, 3 sets of decoration design schemes" and the decoration pit avoidance strategy for free! Click this link:/Zhu Ye /zxbj-cszy.php? to8to _ from = SEO _ zhidao _ m _ jiare & amp； Wb, you can get it for free ~