Helical ducts are thin-walled circular pipes formed by rolling metal strip into a spiral seam. They are primarily used in air conditioning and ventilation systems. The material is mainly galvanized steel, but can also be made from stainless steel, copper, aluminum, colored steel, and micro-perforated steel plates, among others, and are used in various applications.

Advantages:

A. Airtightness:

Each straight pipe is made from a single sheet of metal, ensuring excellent airtightness.

2. During spiral duct installation, there are fewer connections between pipes. The typical length of a round duct is 3-6 meters, while the rectangular duct is only 1-1.16 meters. Round ducts can be longer if permitted.

3. Connecting two ducts requires just one joint, whereas rectangular ducts need two completely separate flange systems for connection.

Supplies:

1. In the same cross-sectional area, the perimeter of a rectangular duct is 13% longer than that of a circular duct. For a rectangular duct with a length-to-width ratio of 1:2, the perimeter is 20% greater than that of a circular duct, 30% for a ratio of 1:3, and 41% for a ratio of 1:4. Therefore, the materials used for manufacturing and the sealant and insulation during installation of circular ducts are less than those for rectangular ducts. 2. For the same insulation effect, circular ducts can use thinner insulation materials compared to rectangular ducts, and also lower-density insulation layers. 3. The number and dimensions of mounting brackets can be reduced. The distance between rectangular duct brackets is 2.5M, whereas for circular ducts, it is 3M. 4. The superior structural characteristics of circular ducts fully allow for the use of thinner sheet materials under the same conditions.

The circular duct's pipeline system is standardized, and due to the standardized dimensions, an entire series of fittings and joints can be pre-manufactured. The connection of circular ducts is straightforward, requiring only one person to install a single circular duct, whereas rectangular ducts at least need two people.

Four, circular ducts exhibit less frictional loss compared to rectangular ducts. This is due to the significant reduction in air resistance in spiral ducts and their accessories, as well as their high airtightness. Consequently, when selecting fans, the required motor power is greatly reduced, thereby lowering the daily operating costs of the system and the initial investment in the fan.