Additional specifications and description
Why use flexible ducts?
Compared to rigid ductwork, flexible ducts offer a quicker and cheaper installation process, as they do not require separate elements such as bends to change direction. The lighter weight also means they need fewer mounting points. Another benefit is that a continuous run of Alutex will have zero leaks.
Why choose Alutex?
The main advantage of “Alutex A23” is its excellent flexibility. Alutex can bend in a tight radius and can compress and stretch. Thanks to this Alutex is easy to route around bends and obstacles and attach to round/oval connectors.
Where is Alutex used?
Alutex is suitable for residential and industrial/commercial HVAC applications. Flexible ducts can be used both for supply and exhaust ventilation systems.
A typical example of flexible ducts in exhaust ventilation and the most common use case for Alutex is transporting air pumped by an exhaust fan in a bathroom, toilet or laundry room to an outside wall grille. In these applications, the exhaust fan is located at the beginning of the duct run rather than at the end. This configuration avoids creating a low-pressure zone inside the duct.
In contrast, supply ventilation (positive pressure applications) allows for longer runs. However, this does not mean that all of the standard galvanised steel and Spiro ducts can be replaced with Alutex. Flexible ducting complements rigid ductwork. For example, Alutex is very convenient for attaching air supply outlets or plenum boxes to rigid ductwork.
Alutex comprises 3 layers of aluminium with a thickness of 7 μm and two layers of polyester with a thickness of 12 μm. A spiral of high-tension steel wire inserted between the layers helps the duct maintain its shape.
The flexible duct is attached to other ventilation elements using long zip ties or metal band clamps. Aluminium tape (Alu tape) can provide additional strength if needed.
Flexible ducts might not always be the best option
The disadvantages of flexible ducts are their higher air resistance/pressure loss and noise levels compared to rigid circular/Spiro ductwork. The flexible construction of these ducts also means that they are not as well suited to negative pressure applications, and they can only tolerate a moderate amount of negative pressure. In cases where it is impossible to avoid negative pressure, the duct run should be kept short.
While flexible ducting is considerably easier to install than standard ducting, there are some considerations to keep in mind. When bending the duct, it must not become kinked. Any kinks in the ductwork will negatively affect airflow. Unlike rigid ducts, which are measured and cut to the exact length, flexible ducts are often left longer than necessary. This extra length can introduce unnecessary bends and turns along the duct run. And in cases where the duct hangs from a ceiling, it will sag between the supports/mounts. All of this reduces the performance of the ventilation system.
Alutex is shipped in a compressed form, which makes its transportation and storage easier. Once unpacked, the duct extends to its standard length of 10 m.