Confined Space Blowers are designed to provide workers with fresh, breathable air while working in confined spaces or used for fume extraction, because air may not move in and out of confined spaces freely due to design, the atmosphere inside a confined space can be very different from the atmosphere outside. Ventilation Blowers need to be properly sized in order to provide the right amount of fresh air or remove contaminates.
What constitutes a confined space?
“A space which by design has limited opening for entry and exit, unfavorable, natural ventilation which could contain or produce dangerous air contaminants, and which is not intended for continuous employee occupancy.”
– Center for Disease Control and Prevention.
Confined Spaces can result in oxygen-deficient atmospheres, flammable atmospheres and/or toxic atmospheres. Oxygen levels can quickly decrease in confined spaces when doing work, such as welding, cutting or brazing. Oxygen levels can also decrease if oxygen is displayed by other gases, such as carbon dioxide or nitrogen. The appropriate oxygen level for workers is above 19.5%, anything below that requires a SCBA unit.
Common Air Blower Designs
Axial – similar to a house fan, Axial air blowers are the most commonly used confined space ventilator due to its compact size and easy portability. Axial air blowers are electrically powered and come in AC or DC models, so ensure there is power available nearby before using an axial blower. Axial blowers generally deliver between 700 and 3400 CFM of free air.
Centrifugal – these types of air blowers have a fan wheel with numerous blades (similar to a hamster wheel). Centrifugal blowers deliver between 1000 and 3000 CFM for maximum air movement or fume extraction. Generally used in larger confined spaces are spaces where there is an abundance of toxic gas/fumes.
Confined Space Blowers are highly recommended when working in storage tanks, process vessels, pits, silos, vats, degreasers, reaction vessels, boilers, exhaust ducts, sewers, tunnels, underground utility vaults and pipelines.