Ventilation Grille with One-Way Backdraft Damper – 170 x 170 mm - outside 120 x 120 inner

Ventilation Grille with One-Way Backdraft Damper – 170 x 170 mm

A practical 3D-printed ventilation grille featuring a gravity-operated one-way backdraft damper, designed to help prevent unwanted reverse airflow.

This is an updated version of my previous design, adapted for a smaller wall opening.

Dimensions

• External grille dimensions: 170 x 170 mm

• Mounting opening in the wall: 120 x 120 mm

• Backdraft flap: adapted to the 120 x 120 mm opening

• Estimated filament consumption: 80–120 g, depending on slicer settings

How does it work?

The grille features a movable, gravity-operated flap that opens when air flows in the intended direction and closes automatically when the airflow reverses.

This helps to:

• Prevent cold air from blowing back into the room.

• Reduce unwanted drafts.

• Limit unpleasant odors entering through ventilation ducts.

• Maintain a clean and modern appearance.

Features

• Fully 3D-printable design

• Gravity-operated backdraft flap

• No springs or additional mechanical components required

• Simple assembly

• Four mounting holes

• Designed for a 120 x 120 mm wall opening

Printing recommendations

• Material: PETG recommended; PLA may be suitable for appropriate indoor conditions

• Layer height: 0.20 mm

• Infill: 15–20%

• Check that the flap moves freely after assembly

Important

The backdraft damper is designed to reduce reverse airflow but does not provide a completely airtight seal.

Before installation, make sure a backdraft damper is suitable for your ventilation system. It may restrict airflow in passive gravity ventilation systems.

If you print this model, feel free to share your make and feedback!