Double Deflection Grilles | rickardair

Double Deflection Grilles

The RICKARD Double Deflection Grilles has been designed to provide a cost effective outlet in an architecturally pleasing package. Our unique design allows us to vary the look of the face and offer various mounting methods. The face can be varied by changing the frame width and depth as required. By using traditionally used aluminium extrusions, this is not possible.

PERFORMANCE

Aerodynamically shaped components reduce noise and improve air flow characteristics.

OPERATION

Adjustable blades allow horizontal or vertical adjustment in either direction, symmetrically or asymmetrically. Adjustability changes throw length, direction and the airflow patterns shape.

INSTALLATION SAVINGS

Standard screw attachment from the face or an optional spring clip attachment is available. Spring clip attachment creates friction between the grille spring and the aperture making installation and removal a snap.

AESTHETICS

Our standard grille is manufactured with slightly wider end flanges. This gives the grille a slightly longer, less boxy look. Equal sized flanges are available if required. Our spring clip option eliminates the need for screws and creates a clean face.

FINISH

High Quality Epoxy Powder Coated Finish available in a range of colours. For an anodized finish an epoxy anodized finish is available. Matt White comes as Standard.

MAINTENANCE

No maintenance required.

DUCT OR BULKHEAD MOUNTING

HORIZONTAL THROW

MEDIUM TO LARGE SPACES REQUIRING LONG THROWS

ZONES WITH A CONSTANT LOAD (WITH/WITHOUT OBD)

USE WITH FANCOIL UNITS

COOLING AND HEATING

USED WITH RICKARDS VAV WALL BULKHEAD DIFFUSERS (WBD’S)

RICKARD Double Deflection Grilles can be used in a multitude of applications. Typically they are intended to be used as constant volume outlets with or without opposed blade balancing dampers. Rickard manufacture and can supply Double Deflection Grilles with OBD’s as required. Double Deflection Grilles are typically used to throw air horizontally in relatively large spaces. They do not automatically regulate the air volume entering the conditioned space as they are constant volume devices.  Consequently, room temperatures will vary with room loads (assuming the duct air temperature and pressure remain constant).

In some cases Double Deflection Grilles are used with Fancoil units. In these cases or in cases where the volume is adjusted upstream of the outlet, it is important to consider the possibility of dumping at low volumes. This becomes more likely since the outlet size remains constant and cannot decrease in size to increase velocity when volumes drop. When a space’s load is likely to fluctuate please select Rickard’s VAV WBD grilles to provide temperature control and higher levels of occupant comfort.

The Rickard Double deflection grilles can be used to supply spaces that require heating or cooling. To ensure that dumping does not occur in cooling and stratification in heating care must be taken to supply the diffusers with adequate pressure.

Adjustable vanes make it possible to easily adjust the direction of the blades by hand. Adjustable blades allow horizontal or vertical adjustment in either direction, symmetrically or asymmetrically. Adjustability changes throw length, direction and pattern shape. In case airflow balancing is required, Rickard manufacture and can supply Double Deflection Grilles with OBD’s.

Our Grilles are supplied with screw attachment from the face as standard or an optional spring clip attachment. Spring clip attachment creates friction between the grille sides and the aperture it fits into.

 

 

The most important practical factors to consider in internal zones is uniform air distribution without dumping and sufficient airflow volumes. Volumes and throws are tabled at various pressures measured at the outlet. The effect of dumping is to overcool the person immediately below the diffuser while the person further away will not be cooled enough.  Dumping is eliminated by ensuring that the discharge air energy from the diffuser is adequate to distribute conditioned air evenly throughout the conditioned area and at the same time provides good secondary room air induction rates.  Providing the total pressure at the outlet is not too low, dumping of conditioned cold air will not take place.

Dumping can also occur when two air streams travelling in opposite directions meet and is therefore redirected vertically downwards. This is avoided by ensuring that diffusers are placed far enough apart to eliminate drafts in the conditioned space.

The table shows the throw or the distance at which air velocity has reduced to 0.25 m/s (50 ft/min). Using this information, diffusers  should be situated such that two adjacent diffusers are separated by slightly less than the sum of their throws. Please note that measurements were taken with the blades set parallel to the direction of flow. The rotation of blades results in an increased pressure drop, a reduction in velocity and a change in the direction of flow i.e. narrower or wider depending on the direction of orientation.

 

DIMENSIONS

 

 

 

 

 

FACE

Slightly wider end flanges (Standard)

Equally sized flanges (Optional)

Special shaped or flange widths (available on request and where practical)

BLADES

Single Deflection

Double Deflection

MOUNTING

Countersunk Screw Mounting

Spring Clip Fixing

ACCESSORIES

Opposed Blade Damper (OBD)

PAINT

Epoxy Powder Coating

Matt White (Standard)

Anodised Silver Finish (Optional)

Special colours for large volume orders (RAL code required)

Wet Spray

Special colours for small volume orders (RAL code required)

SIZES

The following sizes are available as standard. Special sizes can be requested from your local sales representative.