The IICRC S100 Standard and Reference Guide for Professional Carpet Cleaning specifies: (Section 7.5, Drying) …When cleaning carpet, it is highly recommended that drying occur within six to eight hours or less: however, drying time must not exceed 24 hours. Failure of the professional to implement drying procedures could result in a variety of after-cleaning problems. Often, occupant cooperation is needed to expedite drying.
With normal temperature and humidity coupled with use of your heating ventilation and air conditioning (HVAC) system, the carpet should be dry in much less than 24 hours. If it stays damp longer than that, the opportunity for microbial growth and associated odor arises.