Both source capture and ambient air filtration have their place in weld fume collection. The answers really depend on the volume and toxicity of fumes being produced, the size of the weldments and the layout of the facility.
Source capture is the first line of defense for most high-production welding applications. Source capture offers significant benefits, including:
- Lower energy and equipment costs, because the equipment does not have to move as much air. The closer to the source weld fumes can be captured, the lower the cubic feet per minute (CFM) of air to be moved. This translates into dust collection equipment with a smaller motor and much smaller energy consumption.
- Better protection for workers. Source capture keeps weld fumes out of the welder’s breathing zone and out of the ambient air of the facility, providing better protection from toxic elements.
- Cleaner facilities: capturing weld fumes at the source keeps facility air clean and clear and also eliminates dust and grime that falls out of the ambient air onto floors and surfaces.
Source capture systems include:
- Hoods and enclosures (for robotic welding)
- Fume guns
- Fume arms
- Backdraft/sidedraft tables
Ambient air filtration systems clean the air for the entire facility. They can be highly effective, but generally require more energy to use and may not provide enough protection for workers directly exposed to weld fumes. Ambient systems are best used for:
- Situations where source capture is not feasible, such as working with very large weldments or in environments where the use of overhead cranes or other equipment prevents hoods or enclosures from being used.
- In low-production environments where the overall volume of fumes is small.
- As a backup system when source capture alone does not meet air quality standards—for example, when residual smoke rising off of hot weld seams cannot be effectively captured using fume guns or fume arms. Hybrid systems using both source capture and ambient air filtration can generally use a smaller ambient system than would be required if ambient air filtration were used as the primary weld fume collection system.