The runtime of an air scrubber during mold remediation depends on the severity of contamination, room size, airflow rate, and whether active remediation is in progress. In professional practice, air scrubbers are operated continuously for defined phases rather than for a fixed number of hours.

 

1. During Active Mold Remediation

Recommended runtime: 24/7 operation

Air scrubbers should run continuously while mold removal, demolition, or cleaning is in progress.

Continuous operation maintains negative air pressure, prevents cross-contamination, and captures airborne spores released during disturbance.

Units are typically sized to achieve 4–6 air changes per hour (ACH) in residential settings and 6–12 ACH in commercial or healthcare environments.

Example:

1,000 sq ft room with 8 ft ceilings ≈ 8,000 cu ft

A 1,000 CFM air scrubber provides ~7.5 ACH

 

2. After Mold Removal (Post-Remediation Cleaning Phase)

Recommended runtime: 24–72 hours continuously

Continue running the air scrubber after physical removal and HEPA vacuuming.

This “polishing” period captures residual airborne spores and dust.

Many remediation professionals verify completion by conducting post-remediation air testing before shutting down the equipment.

 

3. Minor Mold or Preventive Use

Recommended runtime: 12–24 hours per day for several days

For small affected areas (e.g., closets, bathrooms, crawl spaces) or preventive control:

Run the air scrubber for 2–5 days, at least 12 hours daily

Combine with humidity control (target ≤50% RH) to prevent regrowth.

 

4. Factors That Extend Runtime

You should increase the runtime if:

The building experienced flooding or long-term moisture intrusion

Mold is present in porous materials (drywall, insulation, carpet)

Occupants have asthma or mold sensitivity

Ventilation is limited, or the space is poorly sealed

 

5. When Can You Turn It Off?

An air scrubber for mold can typically be shut down when:

All visible mold is removed

The moisture source is fully corrected

Relative humidity is stabilized below 50%

No musty odors remain

(Ideally) Air sampling meets clearance standards

 

Best Practice Summary

Situation	Recommended Runtime
Active remediation	24/7
Post-remediation	24–72 hours
Minor mold/prevention	12–24 hrs/day for 2–5 days

 

Important Note

An air scrubber does not kill mold—it only removes airborne spores and particulates. Effective mold remediation must also include source moisture control, surface cleaning or material removal, and often dehumidification.