For a leak lasting weeks, this requires professional assessment. DIY cleaners from a hardware store are insufficient because they cannot remediate the hidden moisture or confirm the mold type. Some species common in AC systems, like Aspergillus, can provoke significant allergic reactions or respiratory issues. The first step is always to fix the AC leak at its source—this is non-negotiable to prevent recurrence.

A proper remediation involves extracting water, removing affected porous materials like the carpet section and potentially a portion of the drywall, HEPA vacuuming, and applying EPA-approved antimicrobials. Crucially, a post-remediation verification test from an independent lab is the only way to confirm the spore count has returned to a safe, indoor level and the odor-causing compounds are gone. Given the potential for hidden growth, a professional inspection is strongly advised to define the full scope.