The air-conditioning ducts were originally galvanized steel air-conditioning ducts, and later a new fiberglass air-conditioning duct was introduced. At present, these two air-conditioning ducts are called traditional air-conditioning ducts. They usually adopt the structure of "air-conditioning duct + insulation layer" and require the use of separate insulation materials, so the construction period is long, the production cost is high, the weight is large, the heat insulation performance is poor, the appearance is not beautiful, and installation space needs to be reserved, etc. Insufficient; especially the material corrosion and other problems cause the service life to be generally within 10 years. Compared with today's fast-growing consumer demand, this kind of air-conditioning duct has fallen behind the pace of the times; therefore, this type of traditional air-conditioning duct has a smaller and smaller market share and is facing the fate of being eliminated.

There are many differences between the bag duct system and the traditional metal duct. The bag duct system is specially designed and manufactured for each project. Due to these advantages, the installation speed of the cloth bag air duct is unmatched by the traditional air duct system. The cloth bag air duct can adopt a simple straight pipe system or a more complex shape. The accessories include arc elbows, T-shaped pipes, transition pipes or Other connecting pipes. The bag duct is a larger tubular fiber tube that is hung on a fixed steel cable or rail with a hook and hung above the air conditioning area. The static pressure of the cold/warm air generated by the high-power air-conditioning unit supports the air duct, and flows the cold/warm air to the service area. The air of this type of bagged air duct is completely infiltrated by the gaps between the textile structures on the surface of the air duct. Generally, the average air velocity on the surface of the air duct is 0.05-0.5m/s, and the air supply interval is relatively short. Therefore, multiple air ducts The layout interval is not too large to ensure uniform indoor temperature. Since the air volume per unit area is small, if a large air supply volume is required, a larger surface area of the air duct should be provided.

In the low-temperature food processing workshop, in order to ensure the freshness of the food, the ambient temperature of the air conditioner is generally 10~20°C. The air conditioning system is a small enthalpy difference and large air volume system, and the air supply temperature is generally 5~14°C. At this time, when the wind speed in the air supply area is high, the comfort of processing personnel is very poor. For example, in a workshop at 18°C, when the air supply speed is 2m/s, the processing personnel's body-feeling temperature is 13°C, and if a low-speed cloth air duct is used to supply air, when the air supply speed is 0.1m/s, the body-feeling temperature is 16.3°C. Similarly, in a temperature environment of 14°C, the conventional somatosensory temperature is 7.8℃, while under the condition of breeze, the somatosensory temperature rises to 13.3℃, which greatly improves the comfort of processing personnel and guarantees the freshness of food, thus showing that The use of bag duct systems in food processing workshops is a trend.