Local capture of pollutants

Local capture of pollutants is a IAQ control strategy that aims to remove pollutants at or near their point of origin, preventing them from dispersing into the broader indoor environment. This approach is particularly effective for pollutants generated by localized sources, such as cooking fumes, dust from construction activities, or emissions from specific appliances.

Working principle

Local capture systems typically consist of a hood or enclosure that is placed over the pollution source. The hood is connected to an exhaust system that vents the pollutants directly to the outdoors. The exhaust system should be designed to create a negative pressure in the hood, which will help to prevent pollutants from escaping into the surrounding air.

Enclosing the area where pollutants are generated can also help to control their spread. This can be done by using partitions, walls, or other barriers to create a separate space for the pollution source. The enclosed space should be vented to the outdoors to remove the pollutants.

Applications of local capture

Local capture systems can be used in a variety of settings, including:

Kitchen hoods: Removal of cooking fumes and odors.
Laboratory workstation hoods: Capture and exhaust of hazardous fumes and vapors.
Industrial settings: Capture of dusts, fumes and other airborne particles generated by manufacturing processes.
Commercial cooking equipment: Capture of grease, smoke, and other cooking emissions.
Nail and hair salons: Capture of chemical fumes from nail polish, hairspray, and other products.

Considerations for effective local capture

To ensure the effectiveness of local capture systems, consider the following factors:

Hood design: The hood should be designed to effectively capture the pollutants emitted from the source. This may involve adjusting the hood's size, shape, and placement.
Capture velocity: The capture velocity is the velocity of air that is needed to draw pollutants into the hood. The capture velocity will vary depending on the type of pollutant, the size of the hood, and the distance between the hood and the pollution source.
Exhaust system design: The exhaust system should be designed to effectively remove the pollutants from the hood and vent them to the outdoors. The exhaust system should be sized to handle the airflow from the hood and should be equipped with a fan that can generate enough static pressure to overcome the pressure drop of the system.
Maintenance: Regularly clean and maintain the hood, ductwork, air cleaner, and fan to ensure optimal performance.