Circular Diffuser – CMD

Multi Cone Circular Diffusers, designed to handle large volumes of air and distribute it evenly in a 360° pattern.

Various blow patterns can be obtained by adjusting the core into or out of the frame simply by spinning it.

Circular diffusers manufactured with aluminium spinnings for the blades and frame with moulded plastic internal framework.

Available in wide range of sizes and finishes, with automatic adjustment option.

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Alternate codes

Series GRC, Type ADLR, MC, OD-2, RTLD

We are currently in the process of reviewing our product range. Please check with the Sales Office for all technical details.

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Product Description

The CMD Circular Diffuser is a multi cone circular diffuser, designed with the capability of handling large volumes of air efficiently and the ability to distribute the air evenly in a 360° pattern. The diffusers can be used for both cooled air and warmed air ventilation systems.

Adjustable Circular Diffuser

The circular diffuser has a fully adjustable central cone mounted on a thread mechanism. Various blow patterns can be achieved by simply spinning the cone into or out of the frame body. This ease of adjustment means that air distribution can be altered whenever required to suit the needs of the installation environment.

Spinning the central core of the circular diffuser inwards produces a mostly vertical throw of air, which is ideal for spot cooling or heating where a more localised stream of air is required.

Bringing the central core outwards until it is flush with the outer frame, creates an air throw with a balance between both vertical and horizontal projection.

Extending the inner core further outside of the frame allows the blades to deflect the supplied air sideways for excellent diffusion. When the circular diffusers are installed in ceilings, this setting allows for the use of the condo effect to maximise the affected areas.

Circular Diffuser Air Patterns

As well as the ease with which our circular diffusers can be manually adjusted, we also offer an automatic adjustment system. All units are available with Thermostatic (self adjusting) Element.

Our Circular Diffusers are manufactured with aluminium spinnings for the blades and frame, with a moulded plastic internal framework. They can be ordered in a range of options including Small Format, Large Format and Flat Face. Sizes range from 150mm diameter to 610mm diameter. See Circular Diffuser Specification Data Sheet for more details

Standard finish on the diffuser is to RAL9010 (White), though it can also be ordered in RAL9006 )Silver/Grey), RAL9005 (Black), RAL9003 (White), RAL9016 (White), Mill Finish, chrome Finish or any other RAL code to suit your specific installation requirements. Additional costs may apply.


Plenum boxes are accessories for use with Grilles and Diffusers. They are designed to equalise the pressure profile within the box and hence provide an even velocity at the face of the Grille or Diffuser without the use of Equalising Grids.