Experimental evaluation of the thermal performance of coir mat and green facade as wall insulation in a tropical climate

Passive cooling techniques to minimize the indoor temperature of commercial and residential buildings are of prime importance in research worldwide. A comparison of the potential of coconut coir insulation and green facade to mitigate room heat addition in warm and humid climates prevalent in coastal South India is presented in this paper. Insulation skins like dry coir mat, wet coir mat, green facade, and coir mat with green facade were selected for building walls in the experimental study. The study was conducted during solar hours and non-solar hours on two test cubicles, of which one side wall of the cubicle is made as a reference and the other wall with different insulation. For 24 h, it was found that the dry coir mat had a heat mitigation potential of about 41.45%, whereas the wet coir mat showed 36.3%. Interestingly, it is only 6.15 % for the green facade due to its inefficiency to reject heat during non-solar hours. However, the heat mitigation potential of the green facade can be increased to 40.3% when a coir mat is added. It was also found that the coir mat can reduce heat addition to the wall and reject heat to the ambient due to its porous nature (24.47%).