The microclimate in a room directly affects optimum workplace
conditions and definite technological processes in particular way.
Mechanical ventilation systems are used in order to provide and
keep required air conditions. The most popular material used for
air ducts is sheet steal. More and more often air ducts are made of
plastics, for example polyethylene or PVC (polyvinylchloride). Such
a trend has been observed since the last decade of the XX century
especially in the food industry [1] in which textile ventilation ducts’
high efficiency of air distribution was appreciated.