Berber carpet, as well as many other types of carpet can be constructed from many different types of fibers. With that being said, The industry is made up of primarily 80 to 90 percent nylon carpet, most of it being cut pile carpet. Berbers are loop carpets and are more than likely made from either two types of fibers. The first one is Olefin, also known as polypropylene, which is a man made plastic fiber, and is usually used in the standard to lower end contractors grade berber carpets. The secone one is wool which is a natural protein fiber coming from animals (sheep). You will usually only find wool berber carpets in a higher end installation due to the higher cost of this textile. Now to answer your question, wool fibers are naturally very absorbent. Therefore, wool carpet of any style will always take a little longer to fully dry then its synthetic counterpart. Depending on the ambient temperature and relative humidity in your home, synthetic carpets such as the olefin berber should be fully dry within a 4 hour window if proper extraction technique was used by the cleaning technician, and sufficient ambient air flow is present after the cleaner has left.