Thermal Performance of Insulated Pipe Systems

Abstract

The thermal performance of insulated pipe systems was measured as a function of insulation and pipe system parameters. Insulation parameters included insulation material, thickness, and air gaps at seams and joints. Pipe system parameters were pipe size, hangers, supports, and operating temperature. Over 150 thermal performance tests were recorded and analyzed over a two-year period. Test results show a 15 percent deterioration in thermal performance for a 305-mm (1-ft) insulated pipe section with a 6.4-mm (0.25-in.) butt-joint air gap. The method of insulating pipe hangers and supports is a major component of pipe system heat analysis. Glass fiber and calcium silicate pipe insulations were tested with a variety of hanger and support configurations. The magnitude of heat loss was recorded as a function of several parameters including the degree of hanger/support insulation. A 305-mm (1-ft) glass fiber pipe insulation section containing a hanger had an additional 14 to 40 percent heat loss, depending on the hanger insulation, compared to that of an uninterrupted insulated pipe section. Results from the data analysis and ASTM Practice for Determination of Heat Gain or Loss and Surface Temperature of Insulated Pipe and Equipment Systems by the Use of a Computer Program (C 680) weremore » combined to form computer program HEATLOSS. The good correlation between the thermal performance predicted by HEATLOSS and the actual test data indicates that HEATLOSS can be used to estimate thermal performance effects from variations in insulating material and pipe system design.« less