lambda_p 0.035[W/(m*K)] Thermal conductivity of the insulation panel
lambda_pvc 0.17[W/(m*K)] Thermal conductivity of PVC
Ti 20[degC] Internal temperature
Te 0[degC] External temperature
Rse 0.04[m^2*K/W] External surface resistance
Rsi 0.13[m^2*K/W] Internal surface resistance
sigma 5.67e-8[W/(m^2*K^4)] Stefan-Boltzmann constant
C1 0.025[W/(m*K)] First constant for convective heat transfer coefficient calculation
C2 0.73[W/(m^2*K^(4/3))] Second constant for convective heat transfer coefficient calculation
epsilon 0.90 Emissivity of every surfaces