螺旋风管的种类：
Type of spiral duct:
螺旋风管市场上按材质一般分为三类：镀锌螺旋风管、不锈钢螺旋风管以及复合螺旋风管。其中，不锈钢风管质量最好，适用性强，但价格高。目前市场上流通最广的螺旋风管是镀锌板的。镀锌板螺旋风管，基本是不锈钢螺旋风管的特性，但是价格相对只有不锈钢风管的三分之二甚至更低。复合螺旋风管一般应用在外界环境较为普通，对风管要求不太高的场所。特点由于铁皮容易在各种环境下发生化学反应，造成腐蚀、生锈。而锌在干燥的空气中几乎不发生变化。
Spiral air ducts are generally divided into three categories according to materials in the market: galvanized spiral air ducts, stainless steel spiral air ducts and composite spiral air ducts. Among them, the stainless steel air duct has the best quality and strong applicability, but the price is high. At present, the most widely circulated spiral air duct in the market is galvanized sheet. Galvanized sheet spiral air duct is basically the characteristic of stainless steel spiral air duct, but the price is only two-thirds or even lower than that of stainless steel air duct. Composite spiral air duct is generally used in places where the external environment is common and the requirements for air duct are not too high. Features as the iron sheet is easy to react in various environments, causing corrosion and rust. However, zinc hardly changes in dry air.