A heavy duty grille with a double row of individually adjustable horizontal and vertical blades. Designed primarily for industrial use where a grille with stronger and larger blades is required.
Code 0172. Horizontal front blades with border on four sides.
Code 0175. Vertical front blades with border on four sides.
50mm increments in nominal sizes from 100mm to 1200mm on the length or height.
Aluminium with mechanical and welded joints to
lock the mitred corners of the borders. The blades are secured by screws and nylon inserts which can be tightened once the blades are set in the correct
Mill finish aluminium.
Countersunk screw holes in the border. Size no.
6 x 11/2´´ self tapping screws provided with each grille and painted the same colour as the grille.(Fixing type OF1) See Fixing Methods section for screw fixing centres.
Each grille is shrink wrapped in polythene with
additional cardboard support to the faces.
See pages 10 & 11
Non standard sizes. We can manufacture almost any non-incremental nominal size up to 1200mm square in one section but very large grilles will be made up from multiple units. Please contact Head Office for details. The product codes become 9172 and 9175.
Opposed blade damper. A clip-on opposed blade damper (Code 0106) in mill finish aluminium can be fitted to all models. Non incremental sizes product code is 9106.
Any BS, RAL or NCS colour. Code 0145. Please specify the colour reference.
Un-punched borders on Codes 0172 and 0175. Product Codes become 9172 and 9175 and Fixing type OF2.
PAN ADAPTORS & PLENUM BOXES
Top entry pan adaptor without flange (120mm high). Code 0323.
Top entry pan adaptor without flange (17mm high). Code 0338.
This height of pan should only be used where the spigot diameter plus 50 is equal to or more than the smallest nominal dimension of the pan.
Top entry pan adaptor with flange (120mm high). Code 0328.
Side entry plenum box without flange. Code 0325.
Side entry plenum box with flange. Code 0324.
Details in Sheet Metal section along with codes covering insulated plenum boxes.
Pan adaptors & plenum boxes can be fitted with quadrant dampers in the spigot for either manual (Code 0483) or cord operated (Code 0484) control.
We can also design boxes with non-standard heights where there is limited space above a ceiling or in a cavity. Please contact our
technical staff at Head Office.
• The code for the basic grille should have 13 digits. See page 1.
• Please always give length first then height.
• Add codes for additions / alternatives as suffixes.
A standard heavy duty double deflection grille, 1200mm x 600mm nominal size with borders on all four sides,
horizontal front blades in mill finish, screw fix and with an opposed blade damper would be coded:- 0172/01200/0600+0106+OF1.
PERFORMANCE DATA HEAVY DUTY FOR SINGLE AND DOUBLE DEFLECTION GRILLES
• To size a grille handling 0.5m3/s at 10 metre throw at 025m2/s terminal velocity and sidewall positioned
300mm from ceiling. Correct the throw for ceiling effect, ie. 10÷1.33 =7.5 metres. Enter the nomogram with 0.5m3/s volume and throw 7.5 metres.
Mark the point where the ruler crosses the pivot line. Read off NR(15) and Duct Velocity (1.5). The appropriate pressure drop can be obtained from table 3 (2Pa). Design throws should always be corrected using tables 1, 2, 4 and 5 before using the nomogram.
Data given for isothermal conditions and for free space application, supply air,
with damper fully open, blades set straight.
• Table 3 shows the spread of air achieved by setting the blades at angles of 22° and 45° in relation to the throw from the grille.
Table 3 should be used to determine the number of outlets required to give adequate coverage.
1. Establish the overall throw and spread required, i.e. length and width of the space to be conditioned.
2. Read from table 3 the spread obtained at the
required distance from the terminal. This will
determine the number of terminals required. Example: A room is 10.5 metres long and 6 metres wide. It is intended the air should be discharged from the short wall down the length of the room. At 10.5 metres and blades set at 22°, the spread will be approximately 6 metres, so one terminal will
provide adequate coverage.
3. However, the nomogram on page 10 is based on straight blades. Setting the blades at 22° or 45° will reduce the effective throw of the grille for any given airspeed through it. So it is necessary to apply a
correction factor to the design throw before using the nomogram in order to compensate for this reduction. Table 4 shows the correction factor which should be used as a multiplier to the design throw. The corrected throw can be used in the nomogram.
CORRECTION TO THROW FOR
BLADE ANGLE AND CEILING EFFECT
Example: The throw required is 10.5 metres. The blades are to be set at 22°. The grille is more than 500mm from the ceiling. Multiply 10.5 by 1.5.
This gives a corrected throw of 15.75 metres which should be used in the nomogram.
4. The other factor to be considered in selecting grilles is the heating and cooling of the primary air. Cooled air will tend to fall and this, in particular, should be considered when selecting grilles and diffusers. The amount of drop in the airstream can be determined from Table 5.