How Is A High-vacuum (hi-vac) System Different From A Low-pressure One?

Dust collection systems fall roughly into two categories:

• high volume/low pressure
• low volume/high pressure

High-volume, low-pressure systems are more common. These are likely what you think of when you picture a dust or fume collector. As a point of reference, they might move up to 10,000 CFM (cubic feet per minute) of air at 10-12 inches of vacuum pressure. Dust collectors used for ambient air filtration operate like this, turning over large amounts of air throughout the day. Source capture systems, including collectors attached to welding hoods like the RoboVent Spire, can use this method as well.

Low-volume, high-pressure systems, also known as hi-vac systems, operate quite differently. They move less air but do it at a higher pressure. A common airflow might be closer to 60 CFM at a vacuum pressure of 80 inches. These systems are attached source capture devices like fume guns, fume arms or robotic tip extractors. High vacuum pressure is needed for these systems to overcome the static pressure that results when pulling weld fumes or dust through small pipes.