To avoid re-contamination, when should cleaning of an HVAC system be completed?

Cleaning of an HVAC system should be completed before post-remediation sampling to ensure that any airborne mold spores or contaminated particles are removed from the environment prior to testing. This step is crucial because if cleaning occurs after sampling, any residual contamination could lead to inaccurate results, suggesting that the area is still unsafe when it may have been effectively remediated. By conducting the cleaning beforehand, you create a clearer picture of the air quality and overall conditions of the environment post-remediation, allowing for an accurate assessment of the effectiveness of the mold remediation efforts. Proper timing helps maintain the integrity of the testing process and ensures that the building’s air quality meets safety standards.