Due to the systems of mechanical vapor compression have a high energy consumption for air-conditioned space. Therefore the system of evaporative cooling presents as a promising alternative option for the air-conditioning system. Moreover the pre-cooling system is normally used to reduce an intake ambient air temperature before the air-conditioning system. As mentioned above this research aims to investigate the effectiveness of evaporative cooling system by using a car radiator for air per-cooling. In this research the commercial car radiator was used for cooling inlet ambient air by cooling water. The evaporative cooling system consisted of evaporative cooling panel with a maximum water rate of 40 lite/minute and a maximum air rate of 5100 m3/hr. The results show that most suitable water flow rate of radiator is 10 lite/minute and this radiator can make the differences of air temperature of about 8.9oC. Moreover the results also show that the effectiveness of evaporative cooling system could reach about 73.31% with a maximum sensible heat of 8.43 kW.

The objectives of this study is to increase efficiency of steam boiler 2.5 ton per hour which used liquid petroleum gas LPG as fuel. bringing heat recovery inside boiler chimney stack to preheat feed water with technology heat Exchanger Economize. Taking the economizer with its pipe length of 1000 mm and 62 mm diameter for 64 pipe is a cross flow with staggered tube to increase water temperature before entering the boiler pass to deaerator The study is carried out to compare the differences and savings of the feed water temperature steam boiler efficiency and fuel consumption between having the economizer installed and uninstalled. reference to study The result after installed the heat exchanger economizer the feed water is passed into steam boiler deaerator higher temperature from 38.30°C to 67.20°C which leads to increase efficiency of steam boiler from 81.59 % to 85.65 % meaning that the fuel consumption of steam boiler will be reduced 4.97 %