CURVED BLADE GRILLES / REGISTERS

1/CB Grille with single row of individually adjustable curved blades parallel to the width. 1/CBD Register with single row of individually adjustable curved blades parallel to the width complete with opposed blade damper. 2/CB Grille with single row of individually adjustable curved blades parallel to the width to blow equally in two opposite directions. 2/CBD Register with single row of individually adjustable curved blades, parallel to the width to blow equally in two opposite directions, complete with opposed blade damper.

Sizing Nomogram for Adjustable Curved Blade Grilles & Registers

This type is primarily intended to supply air along the surface of the ceiling or wall into which it is mounted. Terminal Velocity at nearest boundary should not exceed 150 fpm.

Example A Problem:

To size a grille, mounted in the ceiling, to deliver 400 cfm to a room 9ft high when the grille is fitted 6ft from an end wall.

Solution:

Throw to 50 fpm is distance to end wall plus height of room i.e. 6ft + 9ft = 15ft. In the nomogram join 400cfm Air Flow Rate to 15ft on the Throw to 50 fpm Terminal Velocity scale, extend to the pivot line and select a grille of suitable proportions by pivoting about this point e.g. 22" x 20".

Example B Problem:

To size a grille mounted in the ceiling to deliver 600 cfm to a room 48ft long x 15ft wide x 9ft high when the grille is fitted in the centre of the ceiling.

Solution 1.

The grille must be a two way blow and therefore each half of the grille is required to deliver 300 cfm with a throw of half the length = 24ft. In the nomogram join 300 cfm Air Flow Rate to 24ft throw on 50 fpm scale, extend to the pivot line and select a grille of suitable proportions by pivoting about this point e.g. 14" x 10".

Solution: 2.

If the flow is permissible down the end wall, then throw will be plotted on the 150 fpm Terminal Velocity scale. Therefore 300 cfm Air Flow Rate would be joined to 24ft in the 150 fpm scale and extended to the pivot line giving for example a 6" x 6" grille.

Recommended Air Velocities For Various Applications

The services of our Technical Department are always available if required.

Noise Limiting Data

These recommendations are based upon accepted noise ratings for the listed types of environment and upon the sound level of the outlets measured 5ft from the outlet with a room constant of 100.

Noise Chart