Adsorption Cooling System Using Metal-Impregnated Zeolite-4A

The adsorption cooling systems have been developed to replace vapor compression due to their benefits of being environmentally friendly and energy saving. We prepared zeolite-4A and experimental cooling performance test of zeolite-water adsorption system. The adsorption cooling test-rig includes adsorber, evaporator, and condenser which perform in vacuum atmosphere. The maximum and minimum water adsorption capacity of different zeolites and COP were used to assess the performance of the adsorption cooling system. We found that loading zeolite-4A with higher levels of silver and copper increased COP. The Cu6%/zeolite-4A had the highest COP at 0.56 while COP of zeolite-4A alone was 0.38. Calculating the acceleration rate of zeolite-4A when adding 6% of copper would accelerate the COP at 46%

A technique for evaluation of sky luminance distribution in tropical climate: a case study of Northeastern Thailand

Sky luminance distribution (SLD) is an important index for building design. This article proposes an alternative technique for evaluation of sky luminance in a tropical climate without using a sky scanner. The SLD was calculated from the zenith luminance (Lz) and diffuse luminance (Dv). Four consecutive years record of Lz and Dv were used to generate all sky functions. The obtained sky luminance models were validated with the CIE-standard model. Accuracy indexes in terms of MBE, RMSE and R2 were presented. The obtained results indicated that MBE, RMSE and R2 were in the ranges of −16.02% to 5.92%, 4.56–21.46 and 0.96–0.99, respectively. It was suggested that the model proposed in this study would be an effective alternative method for measuring SLD

Performance study of thermoelectric dehumidification system integrated with heat pipe heatsink

The thermoelectric (TE) cooler is a key component in a TE dehumidifier system. This study represents an experimental investigation on the performance of the TE dehumidifier system integrated with heat pipe heatsink. The system is composed of TE modules, fin heatsink, and heat pipe heatsinks. A rectangular fin heatsink is attached to the cold side of TE modules, while the heat pipe heatsink are mounted to the hot side. Air circulates from the test chamber through the cold-side heatsink to remove moisture, and heat pipe heatsink are used to dissipate heat from the hot side of the TE modules. The effect of relevant parameters such as electrical current input to the TE modules and cold air flow rate on the system's performance is studied. It is found that the cold air flow rate and the electrical current input to the TE modules have the highest impact on the system's performance. Improvements to the coefficient of performance (COP) and cooling capacity of the system can be achieved by using heat pipe heatsinks. Experimental results show that the optimum occurs at 3 A of electrical current input to the TE modules and 1.34 g/s of cold air flow rate with corresponding cooling capacity of 93.1 W, yielding an effectiveness of 2.638E-07 L/J and a coefficient of performance (COP) of 1.1

Effectiveness of Motorcycle speed controlled by speed hump

Speed humps are one of the traffic calming measures widely accepted to control vehicle speed in the local road. Humps standards from the western countries are designed mainly for the passenger car. This study, therefore, aims to reveal the effectiveness of speed hump to control the motorcycle speed. This study observes the free-flow speed of the riders at the total of 20 speed bumps and humps. They are 0.3-14.8 meter in width and 5-18 centimeter in height. The results reveal that the 85th percentile speeds reduce 15-65 percent when crossing the speed bumps and speed humps. Besides, this study develops the speed model to predict the motorcycle mean speed and 85th percentile speed. It is found that speed humps follow the ITE standard can control motorcycle crossing speeds to be 25-30 Kph which are suitable to travel on the local road