Review on existing methods of concrete roof cooling

In tropical regions, the roofs of buildings and houses are made of concrete. During summer, these roofs absorb heat and act like a thermal storage material. As a result, inhabitants face a great thermal discomfort during day and night. In order to overcome this discomfort, people use air conditioners, coolers and fans which puts an extra burden on the power plant leading to environmental impact. The various existing methods used to cool concrete roof are cool roof, asphalt shingles, green roof, phase change material cooling, roof pond and evaporative cooling. Even though all these methods provide some reduction in roof temperature, they have many disadvantages like glare issue, water leakage, and maintenance problem, issues like durability, water consumption, extra pumping power, cost and long-term stability. This paper critically analyzes the previous works on various existing methods of concrete roof cooling. The review shows that the real time use of these methods are limited even though researchers have reported good thermal performance. As a future work, pulsating heat pipe (PHP) is suggested in this paper. Since PHP works on two phase flow, large heat transfers are possible. The advantages of PHP promote the use of PHP for concrete roof cooling applications.