A study on the feasibility of a new roof slab insulation system in tropical climatic conditions

Abstract

A roof slab provides an extra robustness and a cyclonic resistance to the structures due to its self-weight. However, its performance in warm humid conditions is unsatisfactory because of the thermal discomfort in the immediate space beneath. Insulation has been recognized as an effective passive approach to address this issue. Thus, numerous insulation systems have been developed throughout the world. In this study, a system proven to be fruitful in tropical conditions was chosen and its negative aspects were recognized. Then, a new insulation system (a system with discontinuous supporting strips) was developed addressing the key drawbacks, and its thermal performance was compared with the prevailing systems. Prototype testing indicated that the negative effect of the supporting strips on the thermal performance of the system is negligible. Further, it was proven that this system achieves a heat gain reduction of more than 75%. An actual scale physical model proved that the system performs even better than a Calicut-tiled roof with a timber ceiling in thermal aspects. Computer simulations deduced that on a sunny day in tropical conditions, about 20% of the peak cooling load reduction can be achieved by the system. In addition, it was found out that about 5% reduction of life cycle cost was achieved by this technique for a lifespan of 10–50 years. And also, it was proven that the insulated slab performs better than an insulated Calicut tiled roof in terms of Life Cycle Costing.