REHAU ARTEVO

heat transmission coefficient (U-value) of window frames = U_f The heat transmission coefficient U (also called thermal insulation value, U-value, former k-value) is a measure for the heat transport through construction components with one or multiple layers, if different temperatures exist on both sides. It indicates the quantity of energy, which flows through the area of 1 m² within one second if the air temperatures on both sides differ by a fixed degree of 1° Celsius (1 Kelvin). The heat transmission coefficient in W/(K•m²) is a specific figure for the material composition of a component. • The greater the heat transition coefficient, the poorer the thermal insulation property of the material • The greater the thermal resistance, the better the thermal insulation property. Proof is possible with: A certification report of an accredited inspection authority of the U_f-value according to EN ISO 10077-2 or passive house certificate (Passive House Institute Darmstadt).

The average frame width. When the frame sections have varying thicknesses, the length-weighted average for the standard window of 1.23m x 1.48m shall be calculated and added.

If optional glass-dividing glazing bars can be installed, their width can be specified here. Here, the width of the glass-partitioning elements is to be specified.