ift-Guideline WA-02engl/3 - Uf-values for PVC profile sections of window systems

Uf-values for PVC profile sections of window systems PVC profile systems are characterized by a large number of different profiles (casement, frame, glazing bar sections, etc.) of a wide variety of geometrical shapes but of comparable thermal insulation properties. Consequently, the key thermal parameters of such systems, e.g. material, number of chambers, installation depth etc. are the same. The great number of individual profiles and possible profile combinations of specific profile systems require a practical approach to identify the Uf-values of the profile sections of such systems. The procedure described by the present Guideline is based on the relationship between Sbmax / B and the Uf-value of the sections. Research into a series of curves obtained from measurement and calculation has shown that this relationship is a workable and practical solution. The Guideline provides the general framework of this method and specifies the minimum quantity of measurements and/or calculations to be performed for a profile system. With increasing complexity of the selected system, the Uf-values of all other types of profile must be identified in addition to the minimum number of sections required.