Cooling effect of some materials in clay composite bricks for tropical region

Abstract

Thermal resistive effect of embedded materials in composite bricks resulting in cooling have been investigated. Different particulate materials and continuous aligned polyethylene fibers were used as supposed thermal resistors in preparing the bricks for houses in tropical region. The face change in temperature {Outside temperature(T1) – Inner Temperature (T2)} across the brick insulated with particulate wood dust, paper, PVC, palm kernel, glass and no-material are 27.9, 27.5, 19.0, 24.0, 25.5 and 26.6 °C respectively after 90 minutes and 26.2, 26.3, 17.9, 22.9 , 22.8 and 24 °C respectively after 120 minutes. It is observed that ΔT°C after 90 and 120 minutes are higher for wood dust and paper than brick with no-material but lower for PVC, palm kernel and glass. A high face change in temperature indicates a drop in temperature T2, resulting in cooling effect if used in building bricks. The same cooling effect was observed when continuous and aligned polyethylene fibers were used to make fiber – clay composite bricks. A side of each sample was subjected to heat of about 70°C and heat transferred measured at the other side as done for particulate embedded bricks. Change in temperature ΔT°C was found to increase with increasing quantity of polyethylene fibers embedded in the samples 34.2°C (0%), 35.4°C (0.5%), 35.5°C (1%), 35.7°C (1.5%), 36.6°C (2%) and 37.4°C (2.5%), these show that heat transfer decreases due to decrease in T2 with quantity of fiber. The result shows that the effect is continuous and tends to equilibrium and the change in temperature becomes steady with time.