Supplied-Air and PAPR Hoods

Clean Air Matrix

RoboVent engineers are experts in every category of air filtration and ventilation. The four categories below represent the major options for treating your contaminated air. RoboVent has designed solutions for each of these categories and has manufactured air filtration systems of unrivaled quality.

For more information about these categories, see Indoor Air Quality 101.


Large blowers and air filtration equipment draw contaminated air from the plant (typically at the ceiling level), filter it and return it to the plant. This is a proven solution in plants welding large parts with overhead cranes. It reduces the haze in the air, resulting in a cleaner working environment, with no negative pressure or heat loss.


Air in the immediate area of the welding activity is captured in a hood system, then filtered and returned to the plant. This is the best solution whenever possible. It allows for a more flexible system and removes the smoke directly from the operator's breathing zone. There are many types of source capture, including overhead hoods, crossflow hoods, fume arms and fume guns, some of which work better than others.


Large exhaust fans draw contaminated air from the plant and exhaust it directly into the environment, typically through the roof or walls. This is a traditional method and often results in negative air pressure. Also, it is very difficult to climate-control your plant and the system may not work well in the winter.

Air in the immediate area of the welding activity is captured in a hood, sent through ductwork, and exhausted directly into the environment. This is a lower capital cost alternative to filtration, but tends to result in high operating costs and large, unsightly ducting systems that work less efficiently with modifications. It also results in negative pressure problems.

Fresh-air hoods provide increased protection against airborne contaminants — such as hexavalent chromium, sparks, chemical and molten metal splashes, and flying debris — that are common in automotive manufacturing, metalworking and fabrication, chemical plants and many other industrial processes. These hoods are available in either supplied-air or powered-air-purifying-respirator (PAPR) designs.

  • Supplied-air hoods deliver a continuous flow of air through a central (or personal) fresh-air pump using compressed-air fittings and hoses.
  • PAPR hoods use a powered fan to pull air through filter packs on the user's belt or hood to provide fresh air.

With a continuous supply of cleaner air, breathing takes less effort, thereby helping the user to remain comfortable and productive. This consistent airflow also discourages re-entrainment of noxious air and thus provides the user with a higher degree of safety.