There is no such thing as a standard dry time. Dry times vary by such factors as the relative temperature and humidity, the condition of the carpet being cleaned, the type of equipment being used, etc. For a moderately soiled carpet, using a basic prespray and rinse technique, at 40-60 % relative humidity at between 68-75 degrees f. using a average truckmount (4ml blower or equivalent) dry times should be aprox. 8-12 hours. May be expedited with dri-pods, snail fans or other. Heavily soiled carpets with the same environmental conditions may take up to 24 hours. People who claim dry times of 2 hours on residential carpet are full of shit.