Additional specifications and description
Iris dampers are used to adjust and measure the airflow within a duct. Iris dampers offer many benefits over traditional damper designs, and they’ve been gaining popularity in modern HVAC systems. Their primary advantage is that they combine measurement and control in one simple-to-install device. They get their name from the way in which the damper mechanism functions - it can shrink and expand its opening very similar to an eye’s iris. This mechanism is, mechanically, very similar to a camera’s aperture, as both use multiple overlapping elements or blades to adjust the size of the orifice. As their mechanism can open fully, these dampers offer unimpeded access to the ductwork for cleaning or inspection. Iris dampers combine accurate air volume metering with a wide range of adjustments, ease of installation and quiet operation, robustness, and long-term reliability, making them a very compelling product.
The purpose of iris dampers is to control the flow of air in supply and exhaust ducts depending on the requirements of the ventilation system. They are equipped with two manometer connections for measuring the pressure before and after the damper, which makes air flow balancing easy. Another benefit of the iris-style damper mechanism is that it offers fine-grain control with a wide operating range. Iris dampers offer superb acoustic qualities compared to other types of dampers. As the damper mechanism creates a circular orifice, it is ideally suited for circular ductwork. Paired together, iris dampers and circular ductwork offer the least disturbance to airflow, making them the quietest damper design. When installed correctly per the recommended method, iris dampers could negate the need to use as many sound attenuators as would be required otherwise.
Construction and mounting instructions:
The damper housing and the iris regulation blades are both constructed out of galvanised steel. The male-male spigots with EPDM rubber gaskets allow for an easy press-fit installation without compromising the air tightness of the ventilation system. The device is suitable for both intake and exhaust ventilation and can operate in both horizontal and vertical orientations. To achieve the best possible results, especially regarding sound attenuation, the recommended installation procedure should be followed. The device should be mounted in straight duct runs, observing the recommended spacing before and after the damper. The spacing before the damper should be at least 4 times the duct diameter. The minimal recommended spacing after the damper is equal to the diameter of the duct.
The iris damper is equipped with two connections for a manometer, which are used to take measurements of air pressure before and after the device. Air volume adjustment is performed via a plastic regulator, using the included plastic wrench. Each damper also comes with a table of airflow values corresponding to the regulator settings. The settings on the regulator and the diaphragm mechanism match perfectly, making the volume control very accurate. The control range of the iris mechanism is from 25 to 100% of the nominal diameter. Please keep in mind that as this damper cannot fully close, it cannot be used as a shut-off damper. Once installed, the device is maintenance-free.
Please note that the final airtightness of the system will depend on several factors, including the installation method.