Azhaili Baharun

Renewable Night Cooled Chill Water Source for Energy Efficient Indoor Radiant Cooling

This study investigates cooling of water at night in Malaysian climate as renewable cooling medium source for radiant cooling purpose. An experiment with a 1.95 m2 steel roof rig structure was constructed and night cooling cycle was conducted during the hot season and cold season of the year. Regression model was developed to predict water temperature after the night cooling process and the corresponding water and roof ratio was established. An annual simulation of a low income home model retrofitted with radiant cooling system charged by night cooled water as cooling medium shows that 99% of the time the thermal condition could meet ISO 7730 category C PMV between-0.7 and + 0.7 . For an outdoor ASHRAE design day condition, the peak indoor operative temperature of 37oC could be lowered to about 30oC with the use of radiant cooling system. The calculated energy saving for the home model was 85% or about 15% of the conventional air system operating cost.

Nocturnal Cooling of Water as Free Cooling Source for Building Indoor Radiant Cooling in Malaysian Climate

Normally mechanical chiller supplies chill water temperature at a higher operating temperature to charge a radiant cooling system in building. Other source of cooling is possible since the operating temperature for radiant cooling is limited by the air dew point temperature. This study investigates cooling of water through long wave radiation to the night sky in Kuching Sarawak, Malaysia and utilise this water for radiant cooling purpose. Mathematical model were developed to predict the cooling power of the nocturnal cooling over typical metal roof and was compared to an experimental data. The measurement from the test model verified the predicted data and a yearly potential from nocturnal cooling in this region was established. The amount of cooled water generated from this night cooling system was also calculated. Results showed that an average of 73 W/m2 nocturnal cooling power is possible in this region.

Wind energy potential in kuching areas of sarawak for small-scale power application

Energy is a catalyst for national development; most of the countries depend on hydrocarbon fuels for power generation. The traditional sources of energy are exorbitant and finite. In addition, they emit excessive carbon dioxide and other gases into the lower layer of the atmosphere which influence the increase occurrence of global warming in the world. Recently, renewable energy’s are gaining more attraction and attention in many parts of the globe, due to non-polluting characteristics. Among the renewable, wind power has emerged as safest and cleanest resource that will satisfy the need of energy in a cost effective way. Wind energy system can suit the energy need for grid and stand alone mode. This paper investigates the potential of wind energy in Kuching for small-scale application. The study employed three years wind speed data spanning from 2010-2012 observed at the Kuching meteorological station. Details of the analysis and potential of using wind energy systems are presented. Additionally, the output performances of two wind turbines are examined on the basis of the computed Weibull distribution.