• 설비공학논문집
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• 제28권2호
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• pp.49-54
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• 2016

The purpose of this study is to analyze the indoor temperature distribution of a room controlled by a personal and portable cooler. As an energy saving strategy, the personal air-conditioning or task conditioning system was developed and installed in office buildings in the 90 s. Many research results regarding the personal air-conditioning (PAC) system were focused on thermal comfort, localized ventilation efficiency and energy savings. However, the conventional PACs were only developed for application in office buildings. In this study, as a type of PAC, a portable cooler was analyzed in terms of indoor temperature distribution changes with the passage of time. The measurement was performed in a bedroom in an apartment house. The results showed that indoor temperature was controlled at about $24^{\circ}C$ around the human body. However, the ambient zone up to 1.5 m away from the the human body stayed at about $27.5^{\circ}C$.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.177-182
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• 2004

Railroad car is one of major public transportation because of an increase in population and heavy traffic problems. We design the concept with air filtration of HVAC system using CFD, select environment-friendly components and compose intellectual HVAC system. For this object, the research to connect HVAC system which control temperature, humidity, air flow with pollutant controlling system which can deal with particular dust, nasty smell. In case of train, fresh air should be provided continuously for pleasant environment of the cabin every season. The air will control outer dust, inner particular dust, $CO_2$ density by air conditioning, heating, humidity regulating, air filtering and ventilating. Ventilation system on passenger cars should be designed for the health and comfort of the passengers.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.404-408
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• 2009

The liquid desiccant air-conditioning system has been proposed as an alternative to the conventional vapor compression cooling systems to control air humidity. The complete system of liquid desiccant air-conditioning system is consisted two main components those are humidifier (regeneration) and dehumidifier. Humidifier part is connected to the load when summer season which is the air condition is hot and humid have to be turned into comfort condition on human. This paper purpose is performances study of air flow rate effect on a structured packed tower on cooling and dehumidifier system using liquid lithium chloride as the desiccant. Experimental apparatus used in this present study is consisted of three components those are load chamber, packed tower and chiller. Load chamber’s volume is $40m^3$, and packed tower dimension is cubic with length 0.4m occupied with packed column. Totally, 15 experimental has done using 5 times repeat on each variable of air velocity that varying on 2m/s, 3m/s and 4m/s with other conditions are controlled. Air inlet initial temperature and relative humidity are set respectively on $30^{\circ}C$ and 52%, desiccant flow rate is 0.63 kg/s, desiccant temperature is $10^{\circ}C$ and desiccant concentration is 0.4. The result of this study shows that averagely, the moisture removal rate and the heat transfer rate are influenced by the air velocity. Higher air velocity will increase the heat transfer and decreasing the moisture removal rate. At adiabatic condition the air velocity of 2 m/s respectively is having the higher moisture removal rate acceleration then the air velocity of 3m/s and 4 m/s until the steady state condition.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1335-1340
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• 2004

Due to the distinct advantages of comfort, drive ability and fuel economy standard, the variable displacement swash plate type compressor which can control the compressor displacement by increasing or reducing the swash plate angle has been developed for automotive air-conditioning system. That can be obtained constant temperature of car room on the variation cooling capacities or engine speeds. This paper was carried out the analysis of swash plate behavior to obtain the forces and moments applied to the swash plate and to get the variable controlability on the variation of compressor speeds and swash plate chamber pressures. The results of simuation agree very well with the experimental data.

• 대한조선학회 특별논문집
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• 대한조선학회 2017년도 특별논문집
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• pp.67-72
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• 2017

This paper presents on the evaluation of thermal comfort in office on offshore. In living quarter of offshore, strict air conditioning performance is required to office on offshore and displacement ventilation is applied to office space which rooms are required to confirm the thermal environment. The computational fluid dynamics (CFD) is performed to calculate the temperature, air velocity in office and thermal comfort such as PPM & PPD is evaluated by the CFD result.

• KIEAE Journal
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• 제7권6호
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• pp.9-15
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• 2007

Ventilation of buildings provide occupants with comfort and plays a very informant role in supplying indoor ventilation requirement. Also, natural ventilation is more comfortable than forced ventilation taking account of mental comfort. Especially factors, airflow velocity and direction etc., should be reflected in establishment of comfortable indoor environment because indoor airflow can directly affect comfort of occupants. However, a device which enables indoor air movement to be analyzed has not existed until now. Hence, it has mostly depended on simulation results of fluid analysis but the results often differ far from reality. PST(Particle-Streak-Tracking) System, an alternative to improve this problem, is currently applied to natural ventilation in building, air conditioning, and airflow analysis in the inside of a plane etc. This study closely examine the property and strength and weakness of PST that is first introduced into KICT and then evaluate applicable possibility.

• 설비공학논문집
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• 제29권3호
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• pp.105-110
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• 2017

Underfloor air distribution (UFAD) is an air distribution strategy for providing ventilation and space conditioning in buildings. UFAD systems use the underfloor plenum beneath a raised access floor to provide conditioned air through floor diffusers that create a vertical thermal stratification during cooling operations. Thermal stratification has significant effects on energy, indoor air quality, and thermal comfort performance. The purpose of this study was to characterize the influence of a linear bar grille diffuser on thermal stratification in both interior and perimeter zones by developing Gamma-Phi based prediction models. Forty-eight simulations were carried out using a Computational Fluid Dynamics (CFD) technique. The number of diffusers, the air flow supply, internal heat gains, and solar radiations varied among the different cases. Models to predict temperature stratification for the tested linear bar grille diffuser have been developed, which can be directly implemented into dynamic whole-building simulation software such as EnergyPlus.

• 설비공학논문집
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• 제24권2호
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• pp.183-189
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• 2012

Most of the domestic residential buildings have used the traditional radiant heating system, circulating hot water through the cross-linked polyethylene(PE-X) pipe buried in the floor panel of the heating space. New type of the heating panel was recently developed using heat pipes with double wicks. Some experiments were carried out in this study to verify the thermal characteristics of this heating system at the unit heating space which surrounded by outer space whose temperature of air be maintained scheduled value with time. Through the various experiments with several parameters, such as flow rate, inlet and outlet temperatures of hot water and the heating duration and so on, we found that the floor heating system with heat pipes was able to reduce the pumping power for hot water circulation by 4~31% compared with the conventional panel heating system using PE-X pipe. These results could be used for optimal design and efficient operation of the heating system as well as improvement of thermal comfort.

• 설비공학논문집
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• 제18권7호
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• pp.535-540
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• 2006

This study was performed In evaluate sleep efficiencies and conditions for comfortable sleep based on the analysis of Physiological signals under variations in thermal conditions. Five female subjects who have similar life cycle and sleep patterns were participated for the sleep experiment. It was checked whether they had a good sleep before the night of experiment. EEGs were obtained from C3-A2 and C4-A1 electrode sites and EOGs were acquired from LOC (left outer canthus) and ROC (right outer canthus) for REM sleep detection. Sleep stages were classified, then TST (total sleep time), SWS (slow wave sleep) latency and SWS/TST were calculated for the evaluation of sleep efficiencies on thermal conditions. TST was defined as an amount of time from sleep stage 1 to wakeup. SWS latency was from light off time to sleep stage 3 and percentage of SWS over TST was calculated for the evaluation of sleep quality and comfort sleep under thermal conditions. As result, the condition which raise a room temperature provided comfortable sleep.

• 대한설비공학회지:설비저널
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• 제14권3호
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• pp.187-199
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• 1985

The low-temperatured radiant heating System like a panel heating system is recognized as nice means to make comfortable indoor environment. Perhaps, 'Ondol' would be a typical example of the Panel heating system. Nevertheless. Occupants in a radiantly heated Space which has an asymmetric radiant field may feel thermally discomfort due to the asymmetric radiation. The aim of this Study is to suggest the fundamental technical data for establishing Standards of thermally comfortable environment when designing a radiant heating System. Thermal distribution of indoor environment and the skin temperature of the occupants were measured at experimental room in KIER (Korea Institute of Energy and Resources). Whole/Regional thermal and comfort Sensation votes of the occupants were taken simultaneously in order to investigate the relationships between thermal environmental factor and the occupants' responses. The effect of an asymmetric radiation on thermal environment and the occupants' responses was analyzed by using a v.r.t.(vector radiant temperature). By this means, the thermally neutral limits for the ambient air temperature and the floor surface temperature by the occupants' responses were Obtained. And the recommended temperature limits of the indoor surface were derived from the experimental work and the theory of radiant and will provide thermal neutrality for man without any discomfort on the part of the body.