Comparison of Zinc Roofed House Temperature Distribution between Open Water Exhausted With Radiator Cooling System Rosdi Ab Rahman 1,a , Masiri Kaamin 2,b , Mahmod Abd Hakim Mohamad 3,c , Azizul Rahman Abd Aziz 4,d and Mohd Hadri Mohamed Nor 5,e 1,2,3,4,5 Pusat Pengajian Diploma, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor. a rosdi@uthm.edu.my, b masiri@uthm.edu.my, c hakim@uthm.edu.my, d azizulaz@uthm.edu.my, e hadri@uthm.edu.my Keywords: Thermal comfort, Cooling systems, Water circulation, Airflow, Radiator, Heat transfer. Abstract. Thermal condition of a house is one of the comfort factors. Traditionally, village houses in Malaysia uses corrugated zinc roofing due to economic reason. Considering the thermal conductivities of the material, space under the roof coverage will intent to occur thermal discomfort due to Malaysian ambient temperature. The roof plays an important role to ensure the house is in a state insulated from the hot sun and rain where the zinc roofing will radiated by the sun in noon and yet become the heat source for in-house area. Thermal discomfort will result due to zinc highly heat absorbing material property. The space under the covering will experience significant temperature increase proportional to the amount of supplied heat from sunlight radiated to the zinc roof, and will further be aggravated if ventilation is poor. The purpose of this study is to compare the temperature distribution by two alternatives methods to reduce the temperature inside a zinc-covered house. The main concept of this cooling system is by splashing water throughout the area of the zinc roofing, where heat exchange process will occur upon contact. The process will dissipate heat from the zinc and will increase the water temperature. This research is focusing on the medium (water) re-cooling process by either open water exhausted or radiator system to state that which one will give better heat exchange. Open water exhausted system heated water will then free fall by gravity into a tank through perforated tube as water droplets. To facilitate higher rate of water-cooling, fan will be provided. Another re-cooling system is the radiator system, which use radiator device to cool down the heated water. Radiator use coolant as the medium to exchange the heat from the roof heated water. By the same heat transfer process, the circulated water temperature will be lower where, which will be recirculation back to the roof. Both systems had been compared about the differences of temperature drop distribution which result the better water re-cooling system. Introduction Thermal comfort as defined by ASHRAE Standard 55 is that condition of mind which expresses satisfaction with the thermal environment. In other words, it describes a person’s psychological state of mind and is usually referred to in terms of whether someone is feeling too hot or too cold. In controlling the thermal comfort to some acceptable level, an alternative cost effective cooling system for corrugated zinc roofing is develop, using circulated water as cooling agent. The corrugated zinc sheet is one of the popular methods used to make roofing for majority of dwellers in traditional Malay rural community as it has the advantage of being cost effective where it is cheaper, easy to construct and durable [11]. However, it also has its own drawback when thermal comfort in the living space covered by the roof is sacrificed. This happens because zinc will efficiently absorb thermal radiation from sunlight and then radiates it down into the living space. [12]. This problem will strengthen if the house does not have proper ventilation as the heat will retained inside. Coupled with global warming effect which already increases ambient temperature higher than normal, the level of thermal discomfort will be unbearable especially in the afternoon [1]. Applied Mechanics and Materials Submitted: 2014-08-01 ISSN: 1662-7482, Vols. 773-774, pp 1178-1183 Accepted: 2015-01-19 doi:10.4028/www.scientific.net/AMM.773-774.1178 Online: 2015-07-15 © 2015 Trans Tech Publications Ltd, Switzerland This is an open access article under the CC-BY 4.0 license (https://creativecommons.org/licenses/by/4.0/)