Filter the incoming air
Filter media treat the air that passes through them. A properly designed intake, intact filter seals and sealed ductwork help limit unfiltered bypass.
- High-efficiency filtration selected for the application
- Sealed housings and connections
- Fresh-air flow matched to the cab
Maintain positive pressure
When inside pressure exceeds outside pressure, the system helps limit inward leakage. Opening a door changes that balance, so recovery must also be assessed.
- Measured differential pressure
- Inspection of seals, floors and cable penetrations
- Testing under actual operating conditions
Treat the air already inside
Recirculation filters particles inside the cab, including those introduced when doors open. It complements fresh air; it does not replace the fresh-air supply.
- Appropriate return-air location
- Suitable recirculation media
- Access for inspection and replacement
Monitor and maintain
Filter loading, leakage and operating conditions change over time. Monitoring and periodic checks help identify deterioration and plan corrective action.
Positive pressure alone does not demonstrate control of every contaminant. Results must be assessed alongside filtration, airflow and air-quality measurements.