how to calculate insulation thickness for ducts?
['General Formula to Calculate Minimum Insulation Thickness Required to Prevent Condensation,t= k * R{(T1 - T2)/ (T3 - T1)} ,', 'Where,', 't = Insulation thickness (in)', 'k = Thermal conductivity.', 'R = Surface temperature resistance.', 'T1 = Dew point temperature (°F)', 'T2 = Operating temperature (°F)']