Getting air scrubbers right is about more than buying a big unit. The goal is to keep airborne particulate below harmful and disruptive levels while supporting productivity. That means matching airflow under load to room volume, selecting the correct filtration class, and deploying the unit so it actually captures dust rather than just moving it around.

Size the airflow for the room and task

Start by calculating room volume (length × width × height). For active dusty tasks, aim for 6–12 air changes per hour (ACH); for maintenance cleaning, 4–6 ACH is typical. Convert ACH to airflow in m³/h, then select a scrubber with sufficient under-load airflow to meet that figure. Avoid free-air ratings—they ignore filters, ducting and real restrictions.

If you are running negative pressure in a sealed area, add a margin to account for leakage and duct losses. Keep ducting short with gentle bends to preserve flow, and provide make-up air to maintain stable pressure.

Specify filtration for the actual hazard

Use staged filtration: a prefilter to capture coarse dust and protect the final filter, and a high-efficiency final stage. For respirable crystalline silica (RCS), welding fume and other fine or carcinogenic dusts, H14 HEPA is recommended. H13 can be suitable for general construction dust where RCS is not present. Check filter integrity, gaskets and clamping—efficiency is only as good as the seal.

Monitor filter loading. A differential pressure gauge or simple trend check (airflow vs. time) helps you change filters before performance crashes. Dispose of filters and dust bags carefully under site waste procedures.

Positioning, zoning and air movement

Use air scrubbers in one of two modes: recirculation to reduce overall particulate, or negative air to contain dust to a work zone. Place the intake close to the dust source or downwind of it; position the exhaust so it does not blow across clean areas. In corridors or long rooms, create a laminar flow path from dirty to clean. Seal gaps and doorways to prevent short-circuiting.

Equipment such as the MAXVAC Dustblocker can be used for recirculation or to help maintain negative pressure in a small enclosure when paired with ducting.

Verification and maintenance

Use a particulate monitor (PM10/PM2.5) or simple smoke tests to confirm capture and flow direction. Keep a brief COSHH record of setup, filter changes and readings. The HSE WEL for RCS is 0.1 mg/m³; you will rarely measure mg/m³ on site, but trending PM counts gives practical assurance your control is improving conditions.

Practical takeaways

• Calculate ACH from room volume; choose airflow under load, not free-air.
• For RCS and fine fume, specify H14 HEPA with good prefiltration.
• Keep duct runs short and sealed; plan air from dirty to clean.
• Track filter loading and change before performance drops.
• Verify with PM readings or smoke; record what you did and why.

Select, place and maintain the scrubber as part of a broader plan: capture at source where possible, control what escapes in the air, and finish with effective housekeeping.