SL

Functional description

Ventilation grilles are air terminal devices for the supply air and extract air of ventilation and air conditioning systems. They direct the supply air into the room. Ventilation grilles with adjustable blades allow for adapting the discharge direction to the local conditions. The result is a mixed flow ventilation in comfort zones and industrial zones, with good overall room ventilation.

Induction slows the airflow down, i.e. the airflow velocity decreases as the distance from the grille increases. The distance at which the airflow velocity reaches a certain defined value, e.g. 0.2 m/s, is called throw distance. The supply air jet from wall grilles that are installed near the ceiling achieves a larger throw distance than a free jet (from a grille that is not installed near the ceiling). Single grilles, groups of grilles and continuous horizontal runs all achieve different throw distances.

In cooling mode it is necessary to take account of the jet deviation towards the occupied zone, which increases as the supply air to room air temperature difference increases and the discharge velocity decreases. In heating mode the supply air jet deviates towards the ceiling. This has no negative effect on the airflow velocity in the occupied zone, but it may affect the complete ventilation of the room.

Sizing example

Given data

V = 335 l/s (1206 m³/h)

Ventilation grilles, made of steel, with adjustable blades

Maximum sound power level of 40 dB(A), with the airflow restricted by 50 %

Nominal height as low as possible

Quick sizing

Type SL or TR

Nominal sizes: 825 × 225, 525 × 325, 625 × 425

Selected: SL/825 × 225

Order example: SL-AG/825×225/M1

Order example: E-SL/1430×225

Order example: SL-EF-AS/1025×125

The weight table shows the available nominal sizes

SL, single grille

Weights apply to ventilation grilles without attachments

SL, horizontal run section

Middle section M: 2000 mm

End section E: 950 – 2025 mm in increments of 1 mm

Weights apply to sections without attachments

Installation and commissioning

• Installation preferably in walls, sills and rectangular ducts
• Installation with installation subframe is recommended

These are only schematic diagrams to illustrate installation details.

Volume flow rate balancing

When several ventilation grilles are installed on the same duct, it may be necessary to balance the volume flow rates.

• AG: Damper unit with opposed action blades, adjustable, secured with a locking screw
• AS: Damper unit with hit and miss damper, adjustable, secured with a locking screw

Air pattern

• Adjustable blades: Set the air control blades individually or together and depending on the local conditions
• D, DG: Air control blades, fitted at 90° to the front blades, can be adapted to the local conditions