This research is the development of an energy - saving water planting kit. The objective is to develop a prototype of an energy - saving water planting kit by applying solar energy as an energy source that is controlled by the Arduino board through a blynk application and study the efficiency of the water culture planting kit. By comparing electricity usage rates between solar energy and electric power from the household. In this study there were 4 experimental sets. The experiment was water cultivation without installation 2 experimental sets and 2 experimental sets were installed using green salad vegetables. In research the 45 days growth period consisted of leaf length and width root length number of leaves and height. There is also a comparison of the efficiency of AB fertilizer and soy milk hormones to reduce chemical usage. The research has shown that the use of the soybean milk hormone provided a high growth rate of Lactuce sativaVar. Longifolla than AB fertilizer. There are many nutrients but only in small amounts. When used as a nutrient for plant growth needs to be changed daily. Considering the economic value using AB fertilizer as a nutrient will be worth more than soy milk hormones. For the installation of the instruction set and the LED lamp was suitable for Lactuce sativaVar. Longifolla growing than not installing the instruction set and the LED lamp. These can save electricity cost of 85 baht per month.

Presently Rental office is famous in downtown that near food center and have good transportation. In Thailand office buildings usually have operating time 8-10 hours per day. So need to improve the building for energy conservation and employee’s comfort. Glasses are one way that heat transfers occur highly. Overall Thermal Transfer Value (OTTV) is a tool for measure heat transfers through building envelope. From OTTV calculation for existing building OTTV is 92.94 W/m2 that over ministerial regulations indicate 50 W/m2. Improving building envelope by add more thickness of glasses can reduce OTTV 1.3% and improving building envelope by film installation can reduce OTTV 47.2% and improving building envelope by add shading can reduce OTTV 48.5%. However each improving policy have each investment cost. Conjoint analysis is consider of many factor to find willingness to pay for each choice. So set policies for energy conservation water and waste management and increase comfort are employees to improve energy conservation water and waste management and increase comfort are 19935.90 17590.50 and 1563.60 baht respectively so can improve building envelope by add shading result in OTTV to 47.8 W/m2 Budget 18000 Baht can be improve organization that payback about 5400 Baht per year. Increase thermal comfort by install table fan. From the result of research expect to apply to improve rental office in the future.

This paper proposes the bidirectional resonant converter with duty cycle voltage control using for CCTV with solar energy. The converter designed at 20 KHz for 20 W with 92.85 % of efficiency is operated at zero voltage switch mode for reducing the losses of converter. The modes of operation divide in two modes for operating bidirectional current. The first part is buck mode which has 5 volt at the output voltage and second is boost mode which has 8 volt at the output voltage. The two operation modes of converter will be discussed in this paper.

Defrosting at evaporator panel is one of working cycles in freezer. Power consumption in defrosting does not meet the objective of using freezer therefore the approach to decrease power consumption in defrosting is one strategy for energy saving. Normally the cycle of defrosting in freezer is a constant time that specify by referring to the highest humidity period. With this control concept the problem of temperature exchange is not occurred from ice accumulation at evaporator panel but it makes the over necessity of defrosting process in the low humidity season and cause the unnecessary power usage in freezer. This research presents the control approach for defrosting by using the difference of the temperature at evaporator and the temperature at chilling area. By using this approach the defrosting process is operated depend on load and the fan is on or off relate to defrosting time. Test results demonstrate that about 12% of power can be saved by this control approach when compared to constant time control.

This research was aimed to study the participation behaviors in the electrical energy saving the factors affected to the participation behaviors and the promotion of the participation behaviors in electrical energy saving of the undergraduate students of the Faculty of Science and Technology Rajamangala University of Technology Phra NaKhon. The participants of 150 students from the Faculty of Science and Technology was also performed based on systematic sampling. The questionnaire was used. The statistical evaluation was also analyzed based on the percentage mean and standard deviation. A 85% of participants is male a range of age to be 19-20 years old (62.7%) second academic years by about 37.3% and a 65.3% of participants has been studying in the major of computer science. Knowledge levels in the electrical energy saving of the most participants are high (13.33%) moderate (62%) and low level (24.67%). The four participation behaviors in the electrical energy saving were analyzed including electrical lighting system air conditioner and ventilator system office electrical system and electrical equipment maintenances resulting in very high level with the average mean of 4.25 and standard deviation of .547. First the participation behavior in the electrical equipment maintenance was very high level with 4.31 and S.D.=.870. Second the participation behavior in the office electrical system was to be 4.27 with S.D.=.828. Third the participation behavior in the air conditioner and ventilator system was to be 4.21 with S.D.=.549. Finally the participation behavior in the electrical lighting system was very slow level with 4.21 and S.D.=.672. By comparing the participation behaviors in the electrical energy saving with the different of academic major of students the participation behaviors in the electrical energy saving did not significant different.