K value for warehouse law is determined by overall coefficient
of heat transfer (Kcal/m2-h-°C)
[Coefficient of heat conductivity or insulation (Kcal/m2-h-°C)/thickness
of insulation (mm)]
Core thickness
K value
(Kcal/m2-h-°C)
Temperature Range
Thickness if replaced
by Styrofoam
42
mm
0.42
+10°C – (-5°C)
75 mm
75
mm
0.24
(-5°C) – (-25°C)
125 mm
100
mm
0.18
(-25°C) – (-35°C)
178 mm
125
mm
0.14
(-35°C) – (-45°C)
213 mm
Remarks
- Temperature range is the reference value. Calculation of economical
panel thickness depends on size and intended use.
- Coefficient of treat conductivity (Kcal/m2-h-°C) :Rigid
polyurethane foam = 0.018 Styrofoam = 0.03