Thermal conductivity value (λ) is a fixed value special for every material. If temperature difference between inner and outer surfaces of a material, which has 1 m2 surface area, 1 m thickness, is 1 Kelvin, its value is defined as thermal conductivity value in terms of heat flow Watt (W). Thermal conductivity values belonging to different building materials are seen in the table below. Low thermal conductivity value means high thermoinsulation performance, and expected insulation performance can be performed with less insulation thickness by Mekpan Panel's sandwich panels that are polyurethane-filled. Polyurethane (PUR) foams provide the best insulating solution in consideration of multipurpose use and long-term performances.



  Polyurethane XPS Rock Wool EPS Glass Wool Concrete
Thermal Conductivity Coefficient λ (W/mK)
katsayısı (λ)(W/mK)
0,022 0,028 0,033 0,035 0,040 1,7



Heat conductivity value (U) is heat quantity flowing vertically through 1 m2 surface in 1 hour, if temperature of two parallel surfaces of a material with d(m) thickness differ 1 K (Kelvin). Thermal conductivity values are taken into consideration during determining sandwich panel's inner filling material thickness.


Panel Thickness U Thermal Conductivity (W/m²K) U Thermal Conductivity (Kcal/m²h C°)
40 mm 0,4973 0,4276
50 mm 0,4056 0,3488
60 mm  0,3424 0,2944
80 mm 0,2611 0,2245
100 mm 0,2110 0,1814
120 mm 0,1771 0,1522
150 mm 0,1426 0,1226