A comparison study of the use of two different heat removal units was conducted to examine the performance of thermoelectric cooler box. The heat removal units employed were a heat sink fin-fan and a double fan heat pipe. Parameters measured as performance indicators are cooling capacity, temperature differences, and COP. In addition, the effect of electrical power on temperature difference and COP was also investigated. The cooler box size is 285 mm x 245 mm x 200 mm and constructed from styrofoam. The results show that there is no difference of the use of a double fan heat pipe or a heat sink fin-fan on the cooler box performances. The Carnot COP decreases with the time, while the experimental COP increases with the time then it is constant after the steady condition has been achieved. Increasing the power decreases the COP but increases the temperature difference.

Due to clean water crisis in the dry season in some places in Indonesia, experiments to find the best distiller to provide distilled water were performed. The long-term goal of this study is to create a distiller that is cheap, simple, easy to make, durable, low maintenance, but produces plenty of distilled water. Three identical conventional distillers with different absorbers had been tested for about 6 days in May 2019. These three distillers were used to evaporate and condense seawater to be distilled water. The absorbers types employed were type A, B, and C. The results show that the distiller with the type C absorber is the best distiller. The distilled water produced is 1.3 liter per day. Therefore, this distilleris recommended to use, develop and study further.

An experiment to determine the performance of a thermoelectric powered by solar panel for a large cooler box was carried out. The size of the cooler box tested was 1000 mm x 500 mm x 400 mm and inside the cooler box, a plastic bottle containing 19 liters of water was placed. The thermoelectric hot side was cooled using a mini channel flowed with water. Meanwhile, the cold side of the thermoelectric was connected to the inner heat sink to absorb heat inside the cooler box. The thermoelectric was powered from a battery charged by solar panels directly. There were 2 solar panels, each of which had a power of 100 WP. The cooler box was tested for 6 days in June 2019. The results showed that the lowest temperature on the thermoelectric cold side was around 16.21°C, while the lowest temperature inside the cooler box was 24.25°C. The experimental COPs obtained were ranging from 0.01 to 0.76. Moreover, in general, solar panels were potential as power sources for thermoelectric cooling systems.

Due to rapid demand on the thermoelectric cooler box, an investigation concerning the effect of water volume on a thermoelectric cooler box performance and its COP has been conducted. The aim of this study is to know the performance and the COP of the cooler box with water volume variations. The conduction heat transfer rate flowing from the ambient to the cooler box space is discussed deeply as this type of heat transfer rate is seldom to be elucidated in the published literature and it can be the dominant of the heat load when there is no water volume inside the cooler box. The cooler box size was 390 mm x 320 mm x 530 mm and the water volume variations employed were ranging from 0 to 4500 ml. The power used was of approximately 51.27 W. The results indicate that increasing the water volume raises the cooler box space temperature and the COP but decreases the conduction heat transfer rate. At 0 ml water volume, the conduction heat transfer rate increases and it gets constant, while at higher water volumes the COP decreases with the time. The effect of the water volume on the heat transfer rate of the air is negligible but it is significant on the total heat transfer and conduction heat transfer.

On the water distribution, the connection of pipe bends is typically obtained either in industry or in housing. On the water distribution, it is often gained the lost of energy or head losses. The amount of head losses occurring in the connection of branch pipe is influenced by several factors, such as: diameter, flow, viscosity, and the angle at the bend pipe connections.This study aimed to determine the effect of variation of the connection point of the bend pipe to the head losses and pressure drop. To do it, the researcher uses an experimental method as a tool by varying the bend angle is 30o, 45o, 60o, and 90o. The result shows that head losses and the small pressure drop occur in the bend angle 30o is 73, 23 mm and 907.606 N/m2. While the head losses and pressure drop is the greatest at an angle of 90o, is 74, 80 mm and 1278,899 N/m2.

This study aimed to enhance distilled water production by employing conventional single-slope solar distillers with continuous seawater input. Three solar absorbers—i.e., a flat absorber, an absorber with 10 fins, and an absorber with 15 fins—were designed and examinedexperimentally. The seawater entered the distillers continuously due to gravity. Moreover, the seawater level inside the distillers was kept constant by using a floating ball valve. The overall size of each distiller was fixed at 1136 mm × 936 mm × 574 mm. The performance of the distillers was analyzed and discussed. The average yields of the flat absorber, the absorber with 10 fins, and the absorber with 15 fins were 1.185 L/d, 1.264 L/d, and 1.404 L/d, respectively. The results of the absorber with 15 fins were about 18.5% higher than those of the flat absorber. The experimental results were compared with the established correlations. This new design with increased water yield provides an effective approach for harvesting sunlight in remote tropical regions for small-scale solar desalination.

In some areas in Indonesia, such as: the southern part of Sumatra until Nusa Tenggara, wind velocity is large enough to be used as a wind power plant with a range of 5-15 knots of wind speed equivalent 2.5-7.5 m / s. However, wind energy has not yet been developed, there are only a wind power plant with a total capacity of 1.4 GW in Indonesia. Mostly, instruments wind power is basically intended for European plains wind speed range of 10-30 knots. So that the necessary adjustments for the Indonesian state that smaller wind speed in order to optimize the system work.The purpose of this study was to determine the influence of the number of blades and wind speed on electric power generated by a horizontal axis wind turbine. The type of blade used is arched plate and fitted with a pitch angle of 30o. Key issues to be examined in this study is how the influence of the number of blades (3, 4, and 5 blade) and wind speed (3m / s, 4m / s and 5 m / s) to the performance of horizontal axis wind turbines.These results indicate that the number of blade 5 gives rpm, torque, power and highest Cp compared to the number of blade 3 and 4. Similarly, the wind speed of 5m / s provide better performance on any number of blade.

No abstract