HVAC installation and duct cleaning routinely disturb silica from drilling, metal fines, insulation fibres and settled debris. Uncontrolled dust undermines indoor air quality, risks exposure to operatives and occupants, and can contaminate newly cleaned ductwork. Practical controls prevent rework and support COSHH duties.

Capture at source

Plan drilling and fixing so extraction is built in. Use on-tool vacuums with tight shrouds for anchors, hangers and penetrations; ensure hoses are short, anti-kink and anti-static to maintain airflow under load. For concrete, consider wet core drilling with immediate slurry capture using a wet-capable industrial vacuum. Where water is unsuitable (ceiling voids, live areas), reduce RPM, use sharp bits and maintain firm shroud contact to limit escape.

When cutting duct sections or linings, use saws or nibblers with local exhaust ventilation (LEV). Cap open duct ends before and after handling to prevent debris entering newly cleaned sections. During brushing or agitation in duct cleaning, pair agitation tools with HEPA-filtered vacuum collection rather than free discharge.

Capture in the air

Isolate work zones with plastic sheeting and create negative pressure so dust migrates into, not out of, the enclosure. Use an air scrubber or negative air machine with HEPA (H14 is preferred for fine and respirable dusts) and duct exhaust air outside where feasible. Position one unit to pull across the workface and a second to mop up dead zones in complex ceiling voids. A compact unit such as a MAXVAC Dustblocker is commonly used to maintain negative air during ceiling or riser works.

Measure performance, not assumptions: check airflow under load (filters fitted) and track particulate levels with a simple PM meter inside and outside the enclosure to confirm effectiveness and trigger filter changes.

Capture on surfaces

Avoid sweeping or compressed air. Use H-class industrial vacuums with high-efficiency filtration for floors, ledges and internal duct surfaces before re-commissioning. Double-bag waste, seal as you go, and remove from site daily to prevent re-agitation. Inspect and clean return grilles, fan housings and tools at the end of each shift to stop carry-over between areas.

RPE and verification

Provide FFP3 or suitable tight-fitting RPE for drilling and cleaning tasks; fit-test and train users. For assurance, combine a visual clean-down standard with spot PM readings and a brief snag list before handover.

Practical takeaways

• Design in on-tool extraction for drilling, cutting and agitation.
• Use negative air with HEPA and simple containment for live buildings.
• Verify with a PM meter and change filters based on performance.
• Vacuum only; never sweep ducts or plant rooms.
• Seal duct ends immediately after cutting or cleaning.

Applied consistently, these steps cut exposure, speed handover and protect indoor air quality.