The original intention of the invention of the cloth air duct is to meet the basic needs of large air supply area and low wind speed in the frozen and refrigerated food industry. At first, the soft material and the special air supply method of the cloth air duct met this need to some extent. However, some other problems followed. For example, ordinary cotton fabrics do not pay attention to fiber permeability, and the cloth air duct cannot be matched with the fan during use, resulting in problems such as air suffocation. The complete air supply effect cannot be achieved. At the same time, the materials used for the cloth air ducts are all ordinary fiber materials, and the fire prevention problem is not considered. There are many fire hazards in the cloth air duct in the project.
In the 1980s and 1990s, with the emergence of new fiber materials and the innovation of textile technology, more and more new materials were used in industrial production. Engineers in the foreign HVAC field have also noticed this trend and tried to use new fiber materials to replace ordinary cotton fabrics for cloth air ducts. This special fiber material with different permeability and fire resistance enables it to be precisely matched with the air conditioning system to ensure a good air outlet effect. Because of its appearance like stockings, foreign engineers named this new fabric air duct system Sox.
The Sox system has many revolutionary advantages. It not only optimizes the use effect of the air conditioner, but also complies with various fire safety regulations of the building. These advantages make it quickly replace the original cloth air duct and become the mainstream air duct product, and the cloth air duct gradually disappeared in the long river of history.
In 2004, DURKEE INTERNATIONAL, which has been committed to the development of international new technologies and new products in the HVAC field, paid attention to the development prospects of the global fiber fabric air distribution system, and introduced the sox system（HAVC air sock ventilation system) to China for the first time, and named it Sox air duct.
Sox air duct system is a flexible end system of outgoing air which is woven from special fibers and replaces traditional cloth air ducts, dampers, diffusers and thermal insulation materials. It is also called fiber fabric air distribution system.
The appearance of the Sox air duct system has brought a technological revolution to the field of ventilation systems in China. Due to its advantages of uniform and comfortable air supply, simplicity and beauty, anti-condensation, convenient installation, cleaning and maintenance, Sox air ducts have been widely recognized by the commercial, public and industrial fields. It is applied to various industries such as supermarkets, professional markets, gymnasiums, convention and exhibition centers, auditoriums, food factories, automobile factories, etc.