In the modern field of Mechanical and Electrical Engineering (M&E), the choice of ventilation solution does not stop at the function of air circulation but must also meet strict standards of energy efficiency, durability, aesthetics and construction costs. Emerging as a leading choice to replace traditional air ducts, spiral round duct (spiral duct) is increasingly asserting its indispensable position in large-scale civil and industrial works. This article will delve into a comprehensive analysis of spiral round duct, helping you understand why this is considered the “backbone” of advanced HVAC systems.
1. What is spiral round duct? Structure and manufacturing principle
1.1. Definition of spiral round duct
Spiral round air duct is a type of air duct with a circular cross-section, specially processed by the spiral lockseam method from thin strips of metal material. The most recognizable feature of this type of duct is the spiral ribs running along the outside of the body of the duct. These ribs are not only the result of the manufacturing process but also act as reinforcements, significantly increasing the stiffness of the duct wall.
Unlike conventional smooth round ducts that are welded longitudinally, the spiral structure of spiral round duct Provides superior negative and positive pressure resistance even when using thinner materials.
1.2. Main structural materials
Quality and durability of spiral round duct depends largely on input materials. Based on information from reputable manufacturers such as Sao Viet Air Duct, the two most popular materials today are:
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Galvanized Steel: This is the most popular material, accounting for a large proportion of the market. The galvanized layer (according to standards such as Z8, Z10, Z12, Z18...) helps protect the base steel from environmental impacts, effectively preventing oxidation and corrosion under normal conditions. This type is suitable for most air conditioning systems, ventilation of factories and office buildings.
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Stainless Steel (Stainless Steel – SUS 304, SUS 201): For special environments with high corrosion such as chemical plants, medical clean rooms, or areas near the sea, spiral round duct Stainless steel is a must. Stainless steel offers lasting durability, chemical resistance and the highest level of hygiene.
2. Outstanding advantages of spiral round duct system
Why do Sao Viet Air Conditioning system design engineers and many leading consulting units prioritize using it? spiral round duct? The answer lies in a series of technical and economic advantages it brings compared to traditional square ducts.
2.1. Optimal aerodynamic performance, reduced pressure loss
This is the biggest advantage technically. Circular cross section is the most ideal shape for transporting liquid or gas. In spiral round duct, air moves with the least resistance because there are no corners that disturb the air flow (turbulent flow) like in square tubes.
Furthermore, the spiral structure inside the pipe is quite smooth, helping to reduce friction along the pipe. This leads to a significantly lower pressure drop. As a result, the supply/exhaust fan does not need to operate at too high a capacity to push the air far, helping to save operating energy for the entire HVAC system in the long run.
2.2. High airtightness, minimizing leakage
Spiral seams are made by automated machinery with extremely high precision, creating a strong and tight mechanical connection. Compared to square ductwork that requires many flange joints and gaskets at the corners, spiral round duct have a longer continuous length (usually 3m or 4m per section), reducing the number of connections. Fewer connections mean less risk of air leakage, ensuring the design airflow reaches the target air outlets.
2.3. High structural strength and good load-bearing capacity
As mentioned, the spiral rib acts as a stiffener. This allows spiral round duct has the ability to withstand much higher pressure differentials (both positive pressure of supply fan and negative pressure of exhaust fan) than square pipes of the same material thickness.
In reality, to achieve the same stiffness, square ducts often require thicker sheet metal or additional reinforcement of threaded rods and V-bars. spiral round duct Allows the use of thinner, lighter materials while still ensuring technical requirements, helping to reduce the load on the ceiling structure of the building.
2.4. Saving investment and installation costs
Although the unit cost of materials per kg may be similar, the total cost for the system spiral round duct usually lower due to the following factors:
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Material savings: Due to good aerodynamic properties, to transport the same amount of air flow, the cross-section of a round tube is usually smaller than that of a square tube, resulting in less material surface area required.
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Fast construction: Connecting the segments spiral round duct Using fittings (sockets) or round flanges is often quicker than using TDC/TDF flanges on square pipes. Light weight also makes transportation and lifting easier, reducing installation labor.
2.5. High aesthetics for the "open ceiling" architectural trend
In modern industrial style office, restaurant and cafe designs, the technical system is often exposed. spiral round duct With a soft, even cylindrical shape and a shiny metal surface, it becomes an impressive interior decoration detail. It brings a feeling of open space, modernity and professionalism compared to the roughness of square air ducts.
2.6. Easy to clean and maintain
Because there are no dead corners to accumulate dirt like square pipes, cleaning the inside is easy. spiral round duct Routine cleaning becomes easier and more efficient. Modern robotic duct cleaners also work best in round duct environments.
3. Quick comparison: Spiral round duct vs Square duct
To better understand the differences, check out the comparison table below:
| Criteria | Spiral Round Air Duct | Square Air Duct |
| Aerodynamics | Best. Smooth air flow, low turbulence. | Inferior. Susceptible to line interference at corners. |
| Pressure loss | Short. | Higher. |
| Noise | Lower due to smooth airflow and rigid construction that reduces vibration. | Can be higher, prone to flat sheet metal vibration (barrel effect). |
| Installation space | Requires slightly higher ceiling space for the same conversion area. | Make good use of narrow ceiling space (can make flat tube). |
| Manufacturing materials | Less material required for the same air flow. | Costs more materials. |
| Tightness | Very high due to the twist joint. | Depends a lot on the skill of the person making the flange and gasket. |
| Aesthetics (Open-air) | Very beautiful, modern. | Usually must be covered or insulated. |
Obviously, except in special cases where false ceiling height is strictly restricted, spiral round duct is the superior choice in most technical aspects.
4. Technical specifications and accessories
When learning about products at factories like Sao Viet Air Duct, you will see the diversity of specifications. spiral round duct to meet all construction needs.
4.1. Common size specifications
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Diameter (D): The size range is very wide, from small pipes D100mm, D125mm, D150mm used for small return/supply air branches, to large main pipes D800mm, D1000mm, D1200mm or even larger according to special requirements.
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Material thickness (Thickness): Depending on the pipe diameter and the working pressure of the system, the thickness of the sheet metal will change. Commonly from 0.48mm, 0.58mm, 0.75mm, 0.95mm to 1.15mm. The principle is that the larger the diameter, the thicker the sheet metal must be to ensure rigidity.
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Standard length: Usually 3 meters or 4 meters per tree for ease of transportation.
4.2. Spiral round duct accessory system
A system spiral round duct The complete system is complete with accessories for diversion, branching and connection. These accessories are also manufactured with high precision to ensure uniformity and tightness:
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Round Elbow (Elbow 90°, 45°): Used to change the direction of air flow.
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Reducer: Convert cross section from large pipe to small pipe (concentric or eccentric cone) to maintain wind velocity.
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Tee, Y-branch: Used to branch the air flow from the main shaft to different areas.
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Coupling: Accessories to connect two straight pipes together (usually male coupling).
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Take-off: Extract air from the main pipe body to the branch pipe or to the air outlet.
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Round Volume Damper (VCD): Adjust the air flow in the duct.
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End cap: Seal the end of the pipe.
5. Diverse applications of spiral round ducts in practice
Thanks to its superior properties, spiral round duct Widely used in most fields requiring air treatment:
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Central air conditioning system (HVAC): Used as cold air supply ducts, return air ducts for office buildings, shopping malls, hotels. Especially popular in large halls, supermarkets with open ceilings.
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Industrial factory ventilation: Exhaust hot air, supply fresh air to factories and warehouses. High pressure resistance helps it transport huge amounts of air over long distances.
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Dust extraction, odor extraction, exhaust gas treatment system: Applications in wood factories, textile factories, industrial kitchens, laboratories. These systems are often used spiral round duct stainless steel to prevent corrosion.
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Staircase pressurization and corridor smoke extraction system: Ensure fire safety for high-rise buildings.
6. Important notes when choosing and constructing
To maximize the effectiveness of the system spiral round duct, investors and contractors need to note:
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Choose the right thickness and material: It is necessary to comply with international standards (such as SMACNA, DW144) or Vietnamese standards (TCVN) on the selection of sheet metal thickness corresponding to the diameter and operating pressure to avoid distortion or vibration during operation.
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Quality of workmanship: Choose a reputable supplier (for example: units with modern pipe bending machine lines like Sao Viet) to ensure even, beautiful spiral lines, tight joints, and no open edges.
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Installation technique: The optical suspension system and brackets must ensure standard spacing to avoid tube sagging. The joints must be sealed with specialized silicone glue or silver tape to ensure no air leakage.
7. Conclusion
Spiral round air duct Not just a passing trend, but a progressive engineering solution that brings long-term performance, economic and aesthetic benefits to construction projects. From superior air conduction, high durability to installation flexibility, this type of duct has proven its core value in the HVAC industry.
Choosing high-quality products from professional manufacturers (such as those provided by Sao Viet Duct System or Sao Viet Air Conditioner) along with precise design and construction will ensure you have a ventilation system that operates efficiently, durably and saves maximum energy. Investing in the system spiral round duct is an investment in the healthy "lungs" of the project.
CONTACT INFORMATION – SAO VIET AIR DUCT MANUFACTURING AND TRADING COMPANY LIMITED
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Factory address: 267 Le Thanh Tong, May Chai, Ngo Quyen, Hai Phong
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Hotline/Zalo:
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Mrs. Hang: 0815.999.826
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Mrs. Giang: 0934.559.168
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Mrs. Linh: 0949.852.886
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Tel: 0985.239.838
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E-mail: vietonggio@gmail.com / dieuhoasaoviet@gmail.com
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Website: onggiosaoviet.vn - dieuhoasaoviet.vn
Let Sao Viet Air Ducts be your partner in creating healthy and safe living spaces!
