chutes of which only one is shown such as exactafeed fbk models manufactured by trutzschler gmbh amp co kg is connected by a conveying conduit 22 and a distributor conduit 23 the card feeders 24 compress the fiber tufts into a fiber lap supplied to respective carding machines 25 which make a sliver formed of parallelized fibers the sliver is processed by sliver coilers deposited into coiler cans 26 and then advanced to the successive machine of the spinning process for example a drafting frame a central air conditioning system 27 which has an air inlet opening 28 is connected with the conduit 3 by means of a conduit 29 with the blower 12 by means of a conduit 30 with the conduit 14 by means of a conduit 31 and with the blower 21 by means of a conduit 32 the conditioned air supplied by the air conditioning system 27 is thus directly introduced into the fiber guiding spaces 3 12 14 and 21 by conduits 29 32 in this manner the conditioned air affects directly the substantially opened fiber tufts whereby a rapid conditioning thereof is achieved the air discharged into the cleaning room from filters 6 and 17.