Ventilation Grille Exterior Gravity Louvre 725x725mm PVC Grey, Vents-Group

Quick Facts — Vents-Group Ventilation Grille GRM-725

• Outer dimensions 725 x 725 mm, mounting holes 640 x 640 mm
• Automatic gravity louvres in grey PVC
• Grille frame in powder-coated metal, grey colour
• One-way airflow — prevents backdraft
• Weather- and impact-resistant, colour does not fade
• Ø4.8 mm mounting holes for easy installation
• For mounting on vertical surfaces (walls) only

The GRM-725 ventilation grille terminates the extract duct and protects against weather and draughts by closing automatically when the fan is off. The grey PVC louvres are lifted open by the airflow during forced extraction and fall back to the closed position as soon as the fan stops.

In strong wind or with a large pressure difference between indoors and outdoors, the louvres may produce some noise when opening and closing — this is normal and does not affect function.

What sets the GRM grille's gravity louvres apart?

The grille frame is made of metal coated with a weather-resistant and mechanically durable polymer coating, giving high resistance to weathering over time without the colour fading. The lightweight PVC louvres open automatically under airflow, ensuring flow in one direction only and quick, simple installation with no moving parts requiring adjustment.

How do the automatic louvres work in operation?

When the fan is running, the louvres are opened by the airflow and let the air out freely. When the fan is switched off, the louvres fall back and close the duct, preventing cold outdoor air or draughts from entering the room through the extract duct. This function makes the grille suitable as a termination in ventilation, air conditioning and heat recovery systems.

Where is the ventilation grille best installed?

The GRM-725 is installed outdoors on vertical surfaces, i.e. walls, as the termination of an extract duct. The grille serves both as a functional backdraft seal and as a decorative duct end fitting, while also protecting against debris and precipitation entering the building.

Model and dimension overview, GRM series

Suitable for: HVAC installers, ventilation contractors, facility managers and builders installing extract air systems.

Industries: HVAC and ventilation, facility management, construction and renovation.

Frequently asked questions (FAQ)

Can the Vents-Group ventilation grille GRM-725 be mounted horizontally, for example on a ceiling?

No, the GRM-725 is intended for mounting on vertical surfaces only, i.e. walls. The gravity louvres rely on gravity to close correctly, which requires vertical installation for the function to work as intended.

Does the Vents-Group ventilation grille GRM-725 require any maintenance?

The PVC louvres should be checked periodically to ensure they move freely and are not stuck due to dirt or ice. No lubrication is needed, and the weather-resistant polymer coating on the frame requires no repainting under normal operation.

What sets a grille with a gravity louvre like the GRM-725 apart from a standard fixed ventilation grille?

A grille with a gravity louvre like the GRM-725 closes automatically when the fan is off, thereby preventing cold air and draughts from flowing back into the building, whereas a standard fixed grille has no moving parts and allows airflow in both directions at all times. The louvre function makes the GRM-725 a better choice as an extract air termination where energy loss through open ducts should be avoided.