The objectives of this study were to study personal factors service quality and the decision to choose the service of savings cooperatives in Bangkok to study personal factors that affect the decision to choose the service of savings cooperative members in Bangkok and to study the quality of service that affects the decision to choose the service of savings cooperative members in Bangkok. The population was 1210043 savings cooperative members in Bangkok in 2019. The samples were randomly selected from the population by Purposive Sampling of 400 people. The sample size was determined according to Taro Yamane method. The data was analyzed using descriptive statistics such as frequency percentage mean and standard deviation. The inferential statistics were: independent sample T-test one-way ANOVA analysis Pearsons Correlation Coefficient and Multiple Regression Analysis. The study results showed that the overall service quality level of savings cooperatives in Bangkok was high. The aspects that the sample group thought was of the highest quality was the facilities and responses to member services. The most important factors affecting the decision to use the services of the sample group were human resource development and service development. The study hypothesis test showed that personal factors namely age and membership duration in a savings cooperative affected the decision to use the service of savings cooperative member in Bangkok at a significant level of 0.05. The cooperative members aged 26-35 years focused on service development less than those aged 46 years and over at the statistical significance of 0.05. The group of 16-year membership focused more onservice development than those at the group of 6-10 year membership and the group of 11-15 years of membership at a significant level of 0.05. The service quality factors on trustworthiness confidence and knowing and understanding service recipients had a positive influence on the decision to use the savings cooperative service on cooperative business development aspect at the significant level of 0.05. The service quality factors on trustworthiness confidence and knowing and understanding service recipients had a positive influence on the decision to use the savings cooperative service on human resource development aspect at the significant level of 0.05. The service quality factors on trustworthiness and knowing and understanding service recipients had a positive influence on the decision to use the savings cooperative service on service development aspect at the significant level of 0.05. The service quality factors on confidence and facilities had a positive influence on the decision to use the savings cooperative service on service area development aspect at the significant level of 0.05.

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 thesis 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.

The objective of this research is to study the combustion behavior of a gas-saving burner S-10 using computational fluid dynamics (CFD). The simulation model was created using Fluent 6.3 in 3D-model of the same size of the burner. LPG pressure of 4 psi was released for this study. The combustion behavior was shown in temperature contour and velocity vector. The CFD results were verified by measuring the temperature around the burner head with a vessel. From the study it was found that the CFD’s results of flow velocity and combustion temperature distributions were validated with the experimental values. The CFD’s result errors were less than 10.35% and 11.87% comparing with the velocity and temperature measurement respectively. The fluid flow and combustion behaviors can be described by this CFD model. Moreover the CFD model of the gas-saving burner S-10 can be applied to improve the thermal efficiency of the burner in the future.

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.

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.