Describe the opening pattern
Record open sides, entrance doors, vehicle routes, prevailing draughts and where people actually wait. Measure any enclosed reception office separately.
A device sized for a stated number of square metres does not establish treatment across an outdoor-connected lobby. Moving air may carry pollutants into and out of the space faster than the assumed room model allows.
Find the problem that needs solving
If the concern is vehicle exhaust, examine source location and site operation with the responsible team. If it is dust entering an enclosed office, assess that office and its entry route.
Do not interpret particle clean air delivery rate (CADR) as evidence of gas removal, and do not promise a clean-air zone in an uncontrolled flow path.
Choose a proportionate next step
Consider source measures, building operation and assessment of an enclosed occupied area before buying a unit for the entire lobby. Any proposed local trial should define the location, operating conditions and limitations.
Comfort feedback alone is not evidence that exposure has been controlled.
Put it into practice
Your planning worksheet
A suitability assessment explaining the limits of uncontrolled airflow.
| Suitability question | Decision implication |
|---|---|
| Is the area continuously open to outdoors? | Do not apply an enclosed-room coverage claim |
| Is there a separate enclosed office? | Survey and size that room independently |
| Does the source involve vehicles or another hazard? | Assess the source and exposure with competent help |
| Can a stable operating scenario be defined? | Document limits before considering a trial |
Sources & context
- US EPA — Guide to Air Cleaners in the Home, second edition
Supports the distinctions between particle CADR, gas filtration, operating speed and clear airflow. Residential technical principles are used here for operational planning, not as workplace or clinical compliance criteria.
Sources checked 9 November 2026. Worksheets are editorial planning tools. Confirm site-specific requirements, current local guidance and the instructions for the equipment you use.
