How to Use an Air Scrubber in Negative Air Pressure Systems

Introduction

Negative air pressure systems are critical in containment zones (asbestos, mold, or infectious disease control). Air scrubbers maintain clean airflow while preventing contaminants from escaping. This guide explains how to set up an air scrubber for negative pressure.

How Negative Air Pressure Works

• Air is exhausted outside (or through filters) at a higher rate than it enters.

• Creates a vacuum effect, keeping contaminants trapped inside.

Step-by-Step Setup

1. Seal the Containment Area

• Use plastic sheeting (6 mil poly) to isolate the space.

• Seal doors, vents, and gaps with tape.

2. Position the Air Scrubber

• Place inside the containment zone.

• Attach ducting to exhaust air outside (or through a window).

3. Create Negative Pressure

• The scrubber should pull more air out than enters.

• Verify with a manometer (pressure difference of -0.02 to -0.05 in. WC).

4. Use HEPA Filtration

• HEPA filters are mandatory for hazardous particles.

• Pre-filters extend HEPA lifespan.

5. Monitor & Adjust

• Check pressure hourly.

• Adjust fan speed if pressure drops.

Common Mistakes to Avoid

❌ Poor sealing (leaks ruin containment).
❌ Undersized scrubber (can’t maintain pressure).
❌ Skipping manometer checks (pressure must stay negative).

Conclusion

A properly set up negative air pressure system with an air scrubber ensures safe, compliant remediation in hazardous environments.