Additional specifications and description
The Constant Air Volume damper, also known as Constant Volume Regulator (CVR) is designed to be fitted inside of regular round or Spiro ducts and is equipped with an air-tight lip seal for easy press-fit installation. It maintains precise air volume metering in a wide range of operating conditions. The operating mechanism uses a spring-loaded control surface that is sensitive even to minute pressure differences and offers a good control response with relatively low airflow rates. The device is simple to use as it is self-calibrating, and the desired flow rate is set with only a single Torx screw. This constant volume regulator is suitable for horizontal and vertical installation in supply and exhaust ducts. Once installed, the device is maintenance-free. As the CVR doesn’t require external power and sensors or controllers, it represents a very cost-effective solution.
Constant Air Volume dampers / Constant Volume Regulators are used in Constant Air Volume HVAC systems. This type of ventilation system is most commonly deployed in large interior spaces such as warehouses, atriums, auditoriums, and theatres or multi-storey buildings. As these ventilation systems have a complex ductwork network, constant air volume dampers function to automatically control the distribution of air. Their purpose is to maintain a predetermined, constant volume of air flowing through them, despite any fluctuations in the air pressure in the ducts. The goal is to achieve a uniform airflow through all supply or exhaust vents, thus improving the comfort inside the building. This is very important in colder climates to combat the so-called thermal stacking effect which can cause hot air to be pushed out of the top of the building while cold air is sucked in on the lower floors.
Construction and installation method:
This Constant Volume Regulator is designed to be mounted inside of standard circular or Spiro ducts and functions in either a horizontal or vertical orientation, both in supply and return ducts. It is constructed of non-flammable (rated M1) plastic and galvanised steel elements. It is equipped with a rubber lip seal that secures it in place inside the duct without the need for any other mounting hardware or sealant. The direction of the device depends on whether it is installed in a supply or extract duct. When installed in extract ducts it can be placed near the diffuser, however, when in a supply duct there should be a distance of at least 3 times the diameter of the duct between the diffuser and CVR. When installed in a horizontal duct run, it is important to observe the orientation of the volume regulator mechanism, it should not be tilted or rotated upside down - the proper direction is marked on the device itself.
The desired airflow is adjusted via a Torx number 10 screw, observing the markings on the device, but note that the mechanism and the flap itself should not be touched / handled during installation. The working mechanism of the CAV damper functions without the need for external power or control - it only has to be set at the desired volume during the installation and will continue to operate maintenance-free.
While the automatic control mechanism is precise, unfavourable operating conditions can cause deviations from the desired air volume. Lower than recommended airflow speeds, pressures exceeding the design specifications, or dust / dirt accumulation will negatively impact the accurate operation of the CAV damper. Please refer to the manufacturer’s data sheet for detailed technical specifications and installation instructions.