Types of ventilation grilles: plastic, aluminum, and steel grilles.

Technical and geometric characteristics of a ventilation grille

• Free visual surface: is determined by the relationship that exists between the visual distance between two slats and the spacing of the slat or distance between the fixing point of one slat and the fixing point of the next.

• Free physical surface: is determined by the relationship between the narrowest spacing between two slats and the spacing of the slat. Possible defects that may occur during assembly can lead to anomalies that imply a variation of 5% in relation to this value.

• Factor K: is a value that describes the aerodynamic resistance against the airflow. Contrary to the free surface, this value describes the relationship between flow that circulates through the grille and the accompanying pressure drop.

• Ce: "Entry loss coefficient". This value indicates the aerodynamic conduction of the airflow when attraction occurs. It is the relationship of the effective air passage through the grille against the theoretical passage.

• Cd: "Discharge loss coefficient". This value describes the aerodynamic conduction when air is expelled. It is the relationship of effective air passage through the grille against the theoretical air passage.

• IP Class: is an international protection value. It indicates the level of protection of the grille against the intrusion of external objects or the penetration of rainwater. It is determined based on the EN 60529 standard.

• Wall anchor: connection element used to fix the grille to the wall.

• Flap: visible part of the frame.

Types of ventilation grilles: plastic and metal grilles

• Injection grilles: usually have individually adjustable slats, allowing the range and height of the propelled airflow to be regulated.

• Floor grilles: whether used for air extraction or suction, their installation allows for the passage of people and heavy equipment.

• Transit grilles: are used to allow the circulation of air through doors and partitions. They may have slats shaped like a "V" to allow the passage of air and prevent the passage of light.

• Outdoor air intake grilles: are designed for the aspiration of outdoor air and to withstand weather aggression. The design of their slats prevents rainwater from entering.

• Linear grilles: usually have a decorative function in rooms and places where they are very visible. Their appearance is usually quite robust. They can be placed on walls, floors, and ceilings.