ocr: - Thermal Conduetivity K-value w.m / - m2.°C (BTU/Hr).in/ft2.0F (constant) R-value: 1/K 1/K =1/K U-value W /r m2.°C - (BTU/Hr)/1t2.9F t t == K/t Thickness Thckness : : R-value 1/U meters inches 1/U = - 1/U - Heat Exchange W (Watts): - Heat Exchange BIU/Hr . W=K .m2.°C = U.m2.C BTU/Hr= - in K .ft2.°F U.ft2.°F m Where K (Conductivity Factor) is constant for each material (not related to thickness), J( (Convection Coefficient) varies inversely with the thickness for the same mean temp R( (Resistance Factor) is simply the inverse of K or U.
