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Return grilles – Series 20.2

Return grilles – Series 20.2
19Pages

Catalog excerpts

CONTENTS Return grilles 2 Quick selection table 3 Quick selection table 6 Quick selection table 9 Quick selection table 12 Information of general interest 16

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Return grilles Description Type 20-45 aluminium grilles, fixed blades at 45° Type 21-45 steel sheet grilles, fixed blades at 45°. Finishes Anodised aluminium in its natural colour. Steel sheet painted in white RAL 9010. Special finishes available upon request. Dimensions for use with mounting frame 20-45-H or 20-45-V When the grilles are fixed with a metal frame, the size of the opening corresponds to the nominal size of the grilles. For example,a grille of 500 x 300 would require an opening of the same dimensions. Dimensions for screw mounting When the grilles are fixed with screws, the...

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Example Case 1. Grille mounted in wall, with duct. Requirements Return Air flow rate 300 m3/h Applicationoffices Sound level__below 25 NR Required pressure loss below 5 Pa Maximum permitted effective velocity3 m/s Solution: With the selection table for return grilles we obtain: Q (Air flow rate) 300 m3/h (or 83,3 l/s) Vk (Effective velocity)2,1 m/s NR (Sound level)22 Ps (Pressure loss) 4,1 Pa Grille type 20-45-H size 600 x 150, 450 x 200 or 350 x 250 Observing the results, the data obtained fulfil the requirements of the project. Case 2. Grille mounted in wall, without duct (free...

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Egg crate grilles (return) Description Type 22-5. Egg crate grilles, constructed in aluminium. Finishes Anodised aluminium in its natural colour. Special finishes available upon request. Dimensions for use with mounting frame 22-5 When the grilles are fixed with a metal frame, the size of the opening corresponds to the nominal size of the grilles. For example, a grille of 500 x 300 would require an opening of the same dimensions. Dimensions for screw mounting When the grilles are fixed with screws, the size of the opening corresponds to the nominal size of the grilles reduced by 5mm in both...

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Example: Return grille mounted in ceiling, without volume control damper. Requirements: Return Air flow rate ______________________________ 600 m3/h Application ______________________________________ Library Required pressure loss _________________________ below 5 Pa Maximum permitted effective velocity __________________ 2 m/s Solution: With the selection table for egg crate grilles for return air we obtain: Q (Air flow rate) _________________________600 m3/h (166,7 l/s) Vk (Effective velocity) ______________________________ 1,6 m/s Ps (Pressure loss) _________________________________ 3,1...

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Door grilles (return) Description Type 24-S1. Aluminium grille with counterframe. Type 24-S2. Aluminium grille without counterframe. Finishes Anodised aluminium in its natural colour. Special finishes available upon request. Dimensions for screw mounting When the grilles are fixed with screws, the size of the opening corresponds to the nominal size of the grilles reduced by 5mm in both length and height. For example, a grille of 500 x 300 would require an opening of 495 x 295. Identification In all descriptions of the grille dimensions, it is supposed that the first dimension is the length...

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Door grilles for air transfer, type 24 General information Grille mounted in door for air transfer. - This type of grille is always delivered with a mounting frame, provided with holes for screwing. - The arrangement of the S-24 blades in inverted “V”, impedes vision through it when applied in doors, partition walls, etc. - Recommended transfer velocity for selection is from 0,75 to 1,25 m/s - For grille type 24-S1 (with counterframe) installation is recommended in walls with upto 55 mm thickness. For walls with a higher thickness, use is recommended of two grilles type 20-45-H as detailed...

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Louvres for exterior air intake or exhaust Description Type 25. Aluminium grille. Finishes Anodised aluminium in its natural colour. Special finishes available upon request. Dimensions for use with mounting frame When the grilles are fixed with a metal frame, the size of the opening corresponds to the nominal size of the grilles. For example, a grille of 500 x 300 would require an opening of the same dimensions. Dimensions for screw mounting When the grilles are fixed with screws, the size of the opening corresponds to the nominal size of the grilles reduced by 5mm in both length and...

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12 Series 20.2 Quick Selection Table (Louvres for exterior air intake or exhaust) Q

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Example: Grille mounted in wall, for exterior air intake, without duct. Requirements: Air flow rate _________________________________ 400 m3/h Application ____________________________________ Store Sound level ______________________________ below 25 NR Required pressure loss ______________________ below 5 Pa Maximum permitted effective velocity _______________ 2 m/s Solution: With the selection table for grilles type 25 we obtain: Q (Air flow rate) ______________________400 m3/h (111,1 l/s) Vk (Effective velocity) __________________________ 1,7 m/s NR (Sound level)...

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Accessories and mounting Type MM Metallic frame for grille mounting. Screw mounting Placing the grille in the opening, it can be screwed directly onto the wall, sheet duct, etc. For mounting in fibre ducts it is recommended to use the metallic mounting frame MM. Fixing with mounting frame Once the metallic frame is located into the wall opening (fasteners are incorporated in the frame), the grille can be placed. Pressing lightly the grille will be attached perfectly to the mounting frame by means of pressure clips. Note: The mounting frame is always provided with drilled holes, offering the...

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Series 20.2 The volume control damper 29-0 modifies the values of sound level and pressure loss given in the selection tables. The corrections to be applied to the table values (for the same effective velocity Vk) depend on the percentage of opening of the damper, as indicated in the following table Special dimensions can be supplied upon request.

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Series 20.2 Information of general interest Sound levels, NR curves Hereafter, recommended sound levels for each type of installation are given. Application NR The NR system, which gradually will replace the NC system, has the advantage of including corrections which apply to the specified criterions, taking into account the type of noise, its duration and its location (see graph and following corrections). Recommended velocities for air distribution units The values given below are approximate and refer to comfort installations, since for industrial applications they may be higher. In...

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Return grilles – Series 20.2 19Pages

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Return grilles – Series 20.2
19Pages