Thickness Optimization of Polyurethane Floor Insulation Based on Analysis of the Heat Transfer in a Multi-Layer

During the year, due to weather conditions, the temperature fluctuations at surface level cause problems in underground pipes as a result of freezing water. One of the best prevention strategies is the use of polyurethane floor insulation for keeping the temperature of clay above zero degrees Celsius. In this study to calculate the minimum thickness of polyurethane insulation layer, the differential equation of energy is solved based on principle of separation of variables using imaginary eigenvalues for consistency with the temperature distribution in multi-layer consist of asphalt, gravel and polyurethane with finite thickness and clay as a semi-infinite medium with periodic thermal boundary conditions at surface level. Numerical approach is performed in Matlab and the results show that by using a thin layer of polyurethane it’s possible to greatly reduce the insertion depth of water pipes.