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Round spiral spiro duct Sendzimir for air supply in ventilation system

Spiral duct - diameter 100 mm - length 3000 mm

Product description

Spiral duct diameter 100 mm and length 3000 mm, galvanised according to the sendzimir process. Suitable for use as extract or supply. Airtight C under the condition that the installation is executed according to EN12237. Galvanised steel DX51D + Z275 (double layered zinc coating 275gr/m²).
The Climate Company
100 Mm
Duct length
3000 mm
Duct type
Spiro duct

Additional specifications and description

• Spiro duct, Airtight C
• Steel thickness: 0.45 mm
• Maximum pressure: 3000 Pa
• Maximum temperature: 90 °C
• Zinc coating: 20 μ each side

What is a spiral duct, and how is it made?:
A spiral ventilation duct is a hard metal tube formed made of galvanized steel (also called galva duct, spiral tube or spiro tube). It is being produced by feeding a steel strip into a machine that continuously bends the metal strip using rollers and shapes it into a spiral. At the same time, the machine presses the edges of the steel strip together, forming an air-tight tube. The piece is then cut to the desired length, inspected and tested before the finished product is shipped.
Spiral ducts are sold under many names, including circular ducts and Spiro ducts.

Why choose spiral ducts?:
Spiral ducts offer a multitude of benefits over other duct designs. They use less material when compared to traditional rectangular ducts (a 32% reduction). Thanks to this, spiral ducts can be lighter and more cost-effective. The spiral construction ensures high structural rigidity and stiffness.
Another significant benefit of this design is that spiral duct runs use fewer connecting elements. This way, they can offer better air tightness thanks to the fewer transverse and longitudinal connections when run in long, straight sections.
The circular cross-section also leads to lower noise generation and pressure loss within the duct, and dust accumulation is also reduced compared to rectangular ducts.
Please note that appropriate measures must be taken to avoid crosstalk between rooms that are connected on the same circuit (= use of silencers).

A good balance of price to performance:
This spiral duct uses 0,45 mm thick steel, with double-sided zinc coating with a thickness of 20 μ.
The maximum operating temperature is 90 °C, and the maximum pressure in the system can be up to 3000 Pa.
Thanks to the high-precision manufacturing process, it can achieve an airtightness rating of class C (according to EN12237).
Please note that the final airtightness of the system will depend on several factors, including the installation method.

Easy installation with lots of options:
A ventilation system based on circular ductwork is typically easier to construct, as in most cases ventilation elements are simply press-fit onto the ducts. A full range of accessories and devices are available for spiral ducts including in-line heaters, fans, bends, reducers, T-pieces, and all types of dampers.

Where are spiral ducts used?:
The spiral duct is the workhorse of modern HVAC. Spiral ducts are commonly used in various types of medium to high-pressure ventilation systems. In addition to standard ventilation, the duct finds its applications in areas such as dust evacuation, carbon monoxide removal, grain processing (silo aeration) etc.
Thanks to their better air tightness, ventilation systems based on spiral ducts, have become ubiquitous in Nordic countries. In cold climates where energy demands for heating are high, and losses have to be minimised, spiral ducts are the obvious choice.

An unexpected highlight of modern interior design:
In addition to their primary function as HVAC ducts, these silver spiral tubes have become a fashion statement themselves. Over the years, visible HVAC installations using spiral ducts have been gaining popularity in shops, restaurants, and many other commercial spaces. The spiral duct as an interior design element has been a mainstay for over a decade, and its popularity shows no signs of slowing down.

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