Saturated refrigerant (Freon, R-12) at 40°C fl ows through a copper tube of 20 mm inside diameter and wall thickness of 2 mm. The copper tube is covered with 40mm thick insulation (k 0.02 W/[m K]). Determine the heat gain per meter of the pipe. The internal and external convective heat-transfer coeffi cients are 500 and 5 W/(m 2 K), respectively. The ambient air temperature is 25°C. Compare the amount of refrigerant vaporized per hour per meter length of pipe for insulated versus uninsulated pipe. The latent heat of the refrigerant at 40°C is 1390 kJ/kg.