• KIEAE Journal
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• v.12 no.6
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• pp.85-92
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• 2012

The Korean government has introduced building regulations with improved energy conservation measures, including higher insulation levels for building envelope. However, there are many existing buildings that tend to consume more energy for heating and cooling than new buildings, as they were built under the former regulations with relatively higher U-values of walls and glazing. In order to improve energy efficiency in existing buildings, green remodelling of building envelope and building services are required. For existing buildings, building services improvements have been achieved through energy service company(ESCO), but much attention has not been paid to building envelope improvements with various reasons, such as uncertainty of energy saving effect design issues and costs. The aim of this study is to evaluate the impact of building envelope improvements in a typical commercial building on its heating and cooling energy loads. The results show that the improvement of glazing with lower U-values has the highest energy saving effects, followed by wall, roof and floor, under the condition of same level of insulation improvements. However, high insulated glazing increased LCC because of higher initial investment costs.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.9
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• pp.628-634
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• 2010

This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space. The fresh air is introduced into the double slab space and passes through the opening bored into the footing beam. The air is cooled by the heat exchange with the inside surface of the double slab space in summer, and heated in winter. This system not only reduces sensible heat load of the fresh air by heat exchange with earth but also reduces latent heat load of the fresh air by ad/de-sorption of underground double slab concrete. In this paper, we proposed a simplified presumption method for the prediction of cooling and heating performance in the system. In conclusion the proposed method has been verified by comparing with the calculated value of the numerical analysis model by using nonlinear two-dimension hygroscopic question.

• Journal of the Korean Home Economics Association
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• v.17 no.2
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• pp.49-56
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• 1979

In Korean housing designs reflect uniqueness as a result of the influence of regional and atmospheric factors. In this regard, the early use of the hot floor (ondol) system is of special significance. This system is still in use today, not only for house-heating purposes in the homes of commoners, but also for cooking in the kitchen. The present study represents an investigation of the ondol structure since its earliest known usage. Methodology involves a documentary examination of the system. In point of time, this begins with the system's earliest usage and proceeds chronnologically down to the end of the Yi Dynasty. Research indicates that something very much like the ondol system appeared in the early tribal society of Mahan and its usage continued in the state of Koguryo (during the Three Kingdoms Period) in the homes of the poor. This unique system which had its origin in cold northern areas was utilized on a much broader basis during the Koryo Dynasty. Coming down to the Yi Dynasty it found acceptance and application in all parts of the peninsula. Variations in major component parts of the structure, such as the fuel hole, the flue, the draft , and the chimney, normally reflect regional dissimilarities. It is perhaps most significant that here-in contrast to other devices we have a system that serves concurrently for both heating and cooking purposes.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.11
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• pp.605-611
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• 2017

The purpose of this study is to calculate the energy consumption rate based on data regarding energy use in office buildings, and to confirm the general characteristics of energy consumption. The energy consumption rate of the building is calculated by dividing the energy consumption by the floor area. The energy consumption rate of small-sized office buildings was calculated as $101.48{\sim}201.55kWh/m^2{\cdot}year$ and in the case of medium-sized buildings, the range was $92.77{\sim}177.89kWh/m^2{\cdot}year$. In the case of small buildings, it was found that the energy consumption was $73.24kWh/m^2{\cdot}year$ in electronic device, $34.31kWh/m^2{\cdot}year$ in hot water supply, and $18.37kWh/m^2{\cdot}year$ in heating. In the case of medium-sized buildings, electronic devices was $73.08kWh/m^2{\cdot}year$, lighting was $18.35kWh/m^2{\cdot}year$ and heating, $15.37kWh/m^2{\cdot}year$. In all of the study buildings, the peak heating energy use was observed from 8:00 a.m. to 10:00 a.m during the winter, and the peak power management was required. Energy use at and around the midnight hour is confirmed to be 40~60% of weekly working hours, so it is necessary to manage power use at night time as well as during the day. In order to improve the accuracy of future studies, it is necessary to make efforts to secure the data with standardized energy measuring units for the various type of buildings.

• Journal of the Korean Solar Energy Society
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• v.37 no.6
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• pp.51-58
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• 2017

This study proposes an appropriate level of insulation standards by region through annual heating energy requirements according to regional climate. The reference buildings out of non-residential buildings approved by the energy saving design standard for buildings were derived in the previous study, in which the annual heating energy requirements for each building were as follows when the insulation standard for building members in four regions (Pyeongchang, Seoul, Gwang-ju, and Jeju) suggested by the energy saving design standard for buildings: $29.8kWh/m^2$ in Pyeongchang, $17.5kWh/m^2$ in Seoul, $14.4kWh/m^2$ in Gwangju, and $16.7kWh/m^2$ in Jeju. To satisfy the passive level of insulation standards for these buildings, in case that roof/floor of buildings in Pyeongchang and Seoul was $0.2W/m^2K$, the minimum window thermal transmittance should satisfy $0.9W/m^2K$ and the minimum wall thermal transmittance should satisfy $0.1W/m^2K$ in the case of Pyeongchang. On the other hand, the minimum window thermal transmittance should satisfy $1.5W/m^2K$ and the minimum wall thermal transmittance should satisfy $0.14W/m^2K$ in the case of Seoul. For Jeju regions, the minimum wall thermal transmittance should satisfy $0.34W/m^2K$ to meet the passive level of buildings. Based on the above results, the thermal transmittance of each member by region should take the outdoor climate condition of the region into consideration to satisfy the passive level of buildings.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.10
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• pp.387-393
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• 2016

A ground source heat pump system maintains a constant efficiency due to its stable heat source and radiant heat temperature which provide a more effective thermal performance than that of the air source heat pump system. As an eco-friendly renewable energy source, it can reduce electric power and carbon dioxide. In this study, we analyzed one year of data from a web based remote monitoring system to estimate the thermal performance of GSHP with the capacity of 3RT, which is installed in a low energy house located in Daejeon, Korea. This GSHP system is a hybrid system connected to a solar hot water system. Cold and hot water stored in a buffer tank is supplied to six ceiling cassette type fan coil units and a floor panel heating system installed in each room. The results are as follows. First, the GSHP system was operated for ten minutes intermittently in summer in order to decrease the heat load caused by super-insulation. Second, the energy consumption in winter where the system was operated throughout the entire day was 7.5 times higher than that in summer. Moreover, the annual COP of the heating and cooling system was 4.1 in summer and 4.2 in winter, showing little difference. Third, the outlet temperature of the ground heat exchanger in winter decreased from $13^{\circ}C$ in November to $9^{\circ}C$ in February, while that in summer increased from $14^{\circ}C$ to $17^{\circ}C$ showing that the temperature change in winter is greater than that in summer.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.692-695
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• 2009

Ohmic joule heating electrodes were developed for the electrical heater of the floor of a room. A composite slurry of super pure black and polyvinylidene fluoride with/without the additives of multi-walled carbon nanotube or kindney stone powder was coated as a thin film on the polyethylene terephthalate film. The performances of heating electrodes were evaluated checking specific conductivity, adhesion strength and hardness. The addition of kindney stone powder increases specific resistance and hardness in a small extent. However, the addition of carbon nanotube increases specific conductivity and hardness. The properties of various compositions of ohmic joule heating electrodes were evaluated.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.3 s.43
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• pp.285-298
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• 1992

In this study, bedclimate was investigated depending on various bedquilts used oin ondol in summer. The environmental room condition was maintained at 26: $1^{\circ}C,\;75{\pm}3\%$ R.H., while the ondol surface was kept at $25{\pm}1^{\circ}C$ without heating. The types of bedquilts were hemp, cotton, quilt made of polyester padding with polyester/cotton cover. Two healthy young women were subjected for seven hours' sleep with two replications for this study. The results are as follows. 1) The range of the temperature under the mattress ($25.2\~32.4^{\circ}C$) was lower than that of the temperature on the mattress ($28.8\~35.5^{\circ}C$), or that of the temperature inside the bedquilts ($30.3\~34.4^{\circ}C$). The humidity inside the bedquilts increased during sleeping, and the range of R.H. was $58\~80\%$. 2) The ranges of bedclimate which subjects feel comfortable were $30.5\~33.8^{\circ}C$ on the mattress, $31.0\~34.9^{\circ}C$, $61\~74\%$ R.H. inside the bedquilts. At this range, the mean skin temper-ature of the subjects was $34.3^{\circ}C\~35.2^{\circ}C$. 3) When there was no heating, the weight of the bedding increased during sleeping, and the weight increase was largest in the case of mattress. 4) There were correlations among the skin temperature of three points of the body (abdomen, thigh, foot) and the temperature and R.H. inside the bedquilt. 5) The effect of the type of bedquilts on the microclimate and physiolosical responses were significant. 6) Generally, when there was no heating, the body heat was transferred to the ondol floor, in summer, heat was transferred mostly through the mattress.

• Journal of Animal Environmental Science
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• v.6 no.1
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• pp.1-14
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• 2000

The structural and environmental characteristics of typical pig houses in different growth phases were surveyed and analyzed. Based on the data for thirty nine selected farms in four provinces, Jeonbuk-do, Jeonnam-do, Gyeongbuk-do, and Gyeongnam-do, in the southern provinces, Korea, the goal is to eventually establish standard pig houses of sow and litter, nursery pigs, and growing-finishing pigs. The survey included farm scale, production specialization, structural dimensions of the houses and their ventilation systems, cooling and heating systems, and floor and pit systems related to manure collection. The survey showed 90∼98% of growing-finishing pig houses adopted the sidewall curtain systems. The sidewall curtain systems, although popular, is not well insulated which leads to excessive heating costs in winter. Regarding flooring and manure collection system of the house, 23∼35% of growing-finishing houses installed scraper systems with concrete-slat floors in Gyeongsang provinces while 52∼78% did in Jeolla provinces. The cause of a large variance in flooring between tow regions could not be academically pinpointed, rather it could be attributed to the advice of neighbors who leads local pig production circle. A general trend toward enlargement and enclosure of pig houses for all growth phases was gaining popularity in most regions in recent years. A steady shift to multisite operation from continuous operation was also observed to prevent a disease transfer. The structural design of a standard pig house with its environmental control systems including ventilation and heating/cooling system was suggested for further validation study. In-depth analysis of the survey data is presented in the Results and Discussion section.

• Journal of the Korean Society of Clothing and Textiles
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• v.14 no.1 s.33
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• pp.44-54
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• 1990

The purpose of this study was to investigate the effects of thickness of the sleeping pad on the physiological responses and the microclimate in the heating ondol room during sleeping time. The measuring points were skin temp., weight loss and body movement as physiological responses and the compression ratio, the temp. on/under the sleeping pad, the inside limp. of the sleeping quilts and subjective sence while 7 hours sleeping. Thickness of sleeping pads was 27.2 mm(A), 34.8 mm (B), 47.9 mm(C) used for 90 days and no used pad 60.7 mm(D). The floor surface temp. was keeping $29{\pm}1^{\circ}C$ while the environmental conditions was at $23{\pm}1^{\circ}C$ ($50{\pm}5\%$ R.H.) The results were as followings; 1) The mean compression ratio after using the sleeping pads for 45 days was about $70\%$ , and it wasn't increased any more thereafter 2) After 2 hours sleeping the temp. under the sleeping pads was shown that C and D were higher than A and B, and the temp. on the sleeping pads was shown that A and C pads were higher than B and D. But after 3-4 hours sleeping the skin temp. of legs was shown that B and D pads were higher than A and C. 3) Weight loss for C pad was significantly higher than others. Body movement and side position in tying was higher in A and C pads than B and D. 4) The inside temp. of quilt for A and C pads were higher in the early part of sleeping period than those of B and C pads and relative humidity was lower in C than others. 5) D pad was softer than others and fatigue degree was turned out to be lowest in D, the highest in A. From this point of view, we concluded that thickness of the sleeping Pad in the heating ondol room had different characteristic from that in no heating ondol room. And 35 mm used pad was turned out to be proper.