The experimental and computational investigation of the cooling process during the heat set previous to the texturing has been presented. Different yarn speed values between 600 and 1400 m/min and inlet temperature values with two different channel material (austenite and Ferrite steel) and fiber type (polyester and polyamide) have been compared. The convective heat transfer coefficients have been computed iteratively based oil the measured values. To reach a reasonable relationship between the geometrical parameters, materials type and the heat transfer values, three-dimensional numerical simulations of the convective flow along the cooling channel were performed. (C) 2004 Elsevier Science Ltd.