A simple method for the estimation of thermal insulation thickness

Selection and determination of optimum thickness of insulation is of prime interest for many engineering applications. In this study, a simple method is developed to estimate the thickness of thermal insulation required to arrive at a desired heat flow or surface temperature for flat surfaces, ducts and pipes. The proposed simple method covers the temperature difference between ambient and outside temperatures up to 250 degrees C and the temperature drop through insulation up to 1000 degrees C. The proposed correlation calculates the thermal thickness up to 250 mm for flat surfaces and estimates the thermal thickness for ducts and pipes with outside diameters up to 2400 mm. The accuracy of the proposed method was found to be in excellent agreement with the reported data for wide range of conditions where the average absolute deviation between reported data and the proposed method is around 3.25%. The method is based on basic fundamentals of heat transfer and reliable data. Therefore the formulated simple-to-use expression is justified and applicable to any industrial application. (C) 2009 Elsevier Ltd. All rights reserved.