• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.808-813
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• 2008

The study was to evaluate the air-conditioning of sleep algorithm. The algorithm was developed through the analysis of brain waves and MST, the experiments using air conditioner was performed in a apartment bedroom. Five female subjects were participated for the experiment. Eight hours of data collection a day was performed under different algorithm, case A, case B and case C. Physiological signals, EEG, ECG, EOG, and EMG, were obtained using polygraph and converted into digital signal. Then, subjects were asked to answer the questionnaire about their thermal sensation after experiment in bedroom. Sleep stages were classified, then TST, Sleep latency and Sleep efficiency were calculated for the three different air conditioner algorithm. As results, TST, Sleep efficiency, questionnaire showed the higher values for Case B algorism than that for other algorism. On the other hand, SWS latency was lower than for other conditions. Therefore, it was concluded that Case B of the algorithm was the best for comfortable and deep sleep.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.11
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• pp.1084-1091
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• 2004

In automotive air handling system, mixing of air streams by the cooler and the heater affects the comfort of cabin room. In the present study, computer-aided analysis is done to improve the thermal comfort and for the optimal design of automotive HVAC system. The simulation software used was FLUENT, and complicate geometries were created by three dimensional CAD. Air flow volume, fir distribution rate and temperature controllability and temperature differences between upper and lower discharge air are analyzed through numerical simulation at vent, floor and defrost mode. Also, velocity vector of sirocco fan is investigated through the scroll housing. The velocity vector magnitude is larger at lower region of fan than that at any other regions. Recirculation and disturbance of air is relatively high near the cut-off edge in the scroll housing. By using the results of this study, the time for prototype production can be reduced and timely decisions can be made to determine initial design directions.

• Journal of the Korea Safety Management & Science
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• v.16 no.2
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• pp.167-174
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• 2014

Heating and air conditioning system is changing rapidly from the traditional HVAC central supply system to the individual supply system with electrical heat pump system (EHP) in Korean school buildings. The individual supply system has advantages to turn on and off individually and to adjust the thermal comfort separately, but energy is wasted in the unoccupied classroom when the last leaving occupant does not turn off the controller. If the controller is to be off automatically while the classroom is not in use, energy consumption would decrease dramatically. This project aims to cease the unnecessary EHP supply in vacant classroom by inputting the class schedule from the central control room to reduce the energy-spending. Experimental measurements were carried out between the controlled classroom that is turned off when not in use and the uncontrolled room that is turned on continually. Occupant's comfort and energy consumption were measured and compared between the controlled case and the uncontrolled case. The energy consumption of controlled classroom case is 30-60% less than that of the uncontrolled classroom case. This result shows that controlling the cooling supply for the unoccupied classroom using the class schedule can decrease the energy consumption remarkably. This supply control system can be used to conserve energy in school structures like universities.

• Journal of the Korea Furniture Society
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• v.22 no.4
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• pp.317-322
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• 2011

Recently, our society is becoming increasingly enthusiastic to acquire knowledge and quality education. Thus, private houses, schools, public libraries and even subways are becoming places to acquire knowledge. Out of all these places, the library, where people visit most frequently to study, has to be quiet, effective and pleasant in order to provide the most efficient place for maximizing learning performance. Many people use public libraries and the age group of people who visit public libraries are very diverse, which makes it particularly necessary to provide the conditions mentioned above. The purpose of this paper is to measure and analyze the differences of thermal comfort and soundscape of library N, which is located in the quiet woods, and library G, which is located in the city center. The measurement and analysis results will be used to evaluate which library has a more pleasant environment.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.128-134
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• 2011

The objective of this study is to analyze the major factors of indoor environment that affect the satisfaction of the occupancy in multi-family residential buildings. The results of this study can contribute to improving the comfort of the residents effectively as they are applied preferentially at the design and construction stages. The indoor environment factors investigated for the analysis included thermal, light, air and the acoustic environment. The individual factors were derived from the 'indoor environment' assessment indices of the green building certificate systems of various countries. Based on these, a questionnaire was prepared to conduct the Post Occupancy Evaluation. The survey results were statistically analyzed.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.11
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• pp.1806-1816
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• 2009

This study analyzes the efficiency of a solar cell attached to an air circulation jacket. A commercially available silicon solar panel was selected and attached at four spots where the body angle was $40-60^{\circ}$ and voltage ($V_{oc}$, V), current ($I_{sc}$, A), and output power (P, W) were measured to determine the efficiency. The solar panel was applied to the outer jacket that operates with two fans to increase the convection that lowers the body temperature. The heavy work of standing, walking, and sweeping of a street sweeper was simulated in the field test. The microclimate within the jacket (with or without a fan) was measured and the subjective thermal, humidity, and comfort sensations were surveyed. SPSS 12.0 statistical package was used for a t-test and Wilcoxon signed-rank test. The results show that the highest efficiency of the solar cell was at the incident angle of $60^{\circ}$ in terms of voltage, current and output power distribution. The microclimate temperature of the air circulation jacket decreased significantly with the high power of the fan and subjects felt cooler than the jacket with a fan at the incident angle of $60^{\circ}$. Air circulation jackets operated by a silicon solar panel showed a significant cooling effect on the wearers.

• Fashion & Textile Research Journal
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• v.8 no.6
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• pp.713-720
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• 2006

Heat conductivity, height, size, elasticity of pillow, stability of shape, hygroscopicity, ventilation, temperature and easy movability, and so on, are considered to be some of major conditions that affect the comfortable sleep. Considering those factors together, the thermal properties, height, shape and feeling of touch, etc, of pillow must be taken into account. Though studies have been conducted to figure out the physical properties of mattress or pillows from the perspective of factors related to the environment of sleep, they are not enough to be used as an index to evaluate the qualitative aspect of sleep. This study tries to consider the effect of pillow filling materials on the comfortable sleep, for which EEG, ECG, EOG, EMG, RT, etc, are to be measured in an attempt to provide the basic data required in proposing the condition that may lead to a sound and comfortable sleep. Three types of pillows that are sold in the market were used for this research in order to evaluate the quality of sleep depending on the filling materials of pillow. All data were statistically processed and the following conclusions were drawn. It was found that the pillow with feathers provided the best comfort as the pillow A turned out to have the shortest sleeping latency(SL) from the perspective of comfort. The pillow B which used the polyethylene is deemed to be suitable for fatigue relieving purpose as it turned out to have the highest slow wave sleep(SWS), but no statistically significant difference was validated. Moreover, the pillow C which used the natural wool was found to have the narrowest contacting area of the pillow and head and provide a great warm heat comfort that may led to a sound sleep because the temperature below the pillow took the longest time to rise.

• KIEAE Journal
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• v.16 no.5
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• pp.65-71
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• 2016

Purpose : The solar shading device carries out roles in a reduction of the cooling load and an improvement of the thermal comfort of occupants by adjusting incident solar radiation. In addition, The shading device enhances the visual sensation comfort by controlling the optical properties. In order to improve building performance and comfort of occupancy, interests in application of the shading devices are getting increasing. This study investigated the application and effectiveness of the external shading device design using statistical analysis. The outcome of this paper could be utilized for the realization of status quo and for an estimation of effectiveness of the shading device Method : The period of data gathering was between 2003 and 2014 and total 459 cases of practical building project were investigated. Firstly, this study defined qualification of the shading devices; the shading device should have minimum protruding lengths of 150mm to outside and have the function of shading control. This paper investigated application rate of the shading device in real project, regional rate of application, annual change of application, materials and types. Result : The statistical analysis showed that the application rate of shading devices was 25.7% in total 459 building design projects. The application rate in central and southern region was 25.3% and 27.0% respectively. Meanwhile, Jeju region showed 22.2%, which was the lowest rate although this area needs more shading devices. The application number of the shading device was the smallest in 2007, but the rate gradually increased after that. The applications was the largest in 2014 due to growing interest of the shading devices in the building.

• Fashion & Textile Research Journal
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• v.12 no.4
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• pp.531-537
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• 2010

The purpose of this study was to review physiological responses and subjective sensations in the cold environment when the subjects wore ensemble with different clo values. Seven healthy male subjects participated in this experiment. This experiment was conducted in a climatic chamber with $-10^sC$ and 50%RH. Subjects wore five different kinds of ensemble[C1 (4.453 clo), C2 (3.452 clo), C3 (2.865 clo), C4 (2.387 clo), and C5 (2.280 clo)]. The experiment was composed of 20 min of rest period, 20min of treadmill exercise(6 km/h) period, 30 min of recovery period. We monitored skin temperature on 7 sites, clothing microclimate and subjective sensations. The clo value had positive correlations with mean skin temperature and clothing microclimate. The subjects feel more warm and humid as the clo value goes up. The subjects reported comfort when they wore C1 and C2 ensemble having over 3 clo value. However, they felt less comfortable during the exercise period since there was high humidity. Skin temperature on the extremities were more dramatically changed by the exercise rather than clo value. Thus it seems that in the cold environment, heat balance can mostly be controlled by the choice of clothing, and the clothes with high clo values can provide higher insulation. In conclusion, our findings suggest that it would be more effective to control clo value depending on the activity level for maintaining comfort level in the cold environment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.1
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• pp.1-6
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• 2006

This study was performed to evaluate sleep efficiencies and conditions for comfortable sleep based on the analysis of EEGs and MST under four thermals conditions. Five female subjects who have similar life cycle and sleep patterns were participated for the sleep experiment. Their age was from 20 to 22 years old. They were healthy, and had regular sleep with consistent bed and wakeup time. It was checked whether they had a good sleep before the night of experiment. Experiments were performed in an environmental chamber of $4.1\times4.9\times2.7m$ size. EEGs were obtained from C3-A2 and C4-Al electrode sites. Sleep stages were classified, then TST, SWS latency and SWS/TST were calculated for the evaluation for sleep efficiencies on thermal conditions. As results, it was concluded that indoor thermal environments of $24\~26^{\circ}C$ was the best for comfortable and deep sleep.