Gravity Louver Fan

Insulation & Ventilation

A gravity louver fan (or gravity shutter exhaust fan) is a wall-mounted ventilation unit equipped with louvers (slats) that open automatically from the pressure of the outgoing air when the fan turns on, and close completely by force of gravity when the fan switches off.

How It Works & Primary Purpose

Automatic One-Way Seal: When turned off, the louvers rest closed, creating a barrier against outdoor elements.
Prevents Backdrafts: Blocks cold drafts, hot outside air, dust, wind, rain, insects, and pests from entering through the vent opening.
No Motorized Actuators: Unlike motorized dampers, gravity louvers require no extra wiring or motors to open and close—saving cost and reducing failure points.

Additional Information
Enquiry

Common Applications

Garages & Workshops: Exhausts fumes, dust, and excess heat while preventing pests or rain from entering when not in use.
Greenhouses & Agriculture: Controls temperature and humidity while sealing out outdoor weather when ventilation is off.
Attics & Warehouses: Provides high-volume air turnover for large spaces while preserving indoor temperatures during winter.
Commercial Kitchens: Venting heat and moisture through exterior walls without leaving an open hole in the structure.

Key Features to Consider

Feature	Details
Material	Aluminum or galvanized steel louvers resist rust and weather better than plastic, especially in outdoor exposures.
Airflow Capacity (CFM)	Ranging from small 10-inch units (~600 CFM) to large 30+ inch industrial units (5000+ CFM). Choose based on room volume and required air changes per hour.
Weather Resistance & Noise	Look for felt-padded or quiet-closing louvers to reduce flapping noise on windy days when the fan is off.
Speed Control & Thermostats	Many units pair with external line-voltage thermostats or speed controllers for automated temperature regulation.