Customers always ask how long will it take for a carpet to dry? I'm sure you've read the "dries in an hour" ads from the Chem companies
( these are not extraction companies so they can't apply any deep cleaning techniques as they wouldn't be able to dry the carpet).
There is no exact answer as every carpet has its own density and degree of soil ,combined with the time of year, the days temperature, humidity, if your heat is on or air conditioning. Also if it is a basement that is being cleaned, however the other factors to consider is 1. whether the operator is making the proper passes to insure the area he is cleaning is dry enough to move on. 2. is the equipment being used to it's potential? or is it powerful enough to extract from a long distance? Inform yourself as to the type of equipment being used and the manufacturer of the equipment, the internet will be your guide to the capabilities of your cleaners equipment.
Craft Carpet Care uses the Prochem 650 HP dual wand hot water extraction system. It is powered by a 3 cylinder Hyundai engine with 68 horsepower ,allowing us to run 2 separate wands and hoses up to 300 feet each. or a single hose up to 600 feet , more then ample to attain the optimal drying capacities for a proper job.
There are numerous machines on the market with horsepower anywhere from 8 hp and up. A substandard system will not do the job 'that a higher powered system will do . In closing, an average carpet cleaning with normal dirt and wear will take approximately 8 hours to dry on a good dry day; add a few hours on a damp day, but surely never more than 24 hours.