• Journal of the Korean Solar Energy Society
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• v.33 no.6
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• pp.54-61
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• 2013

This is study on the glazing performance of the apartment house to predict energy saving rate when the early design stage by calculating heating load. there are various factors of the window type in apartment building to save energy such as window's U-value, SC or SHGC, window wall ration, frame factor, sunshade coefficient and so on. In this study, we analyzed the heating load focused on the U-value, SC and window wall ration using variable heating degree days method for a small and middle size units $59m^2$, $84m^2$, respectively. Each cases were calculated heating load of the real models compared to standard model to predict energy saving rate. From those cases it was drew the conclusion that were window's U-value, SC and window wall ration for the small and middle size units to expect 10% energy saving rate at least.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3307-3314
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• 2012

The annual energy demand of the standard rural house models was analyzed using the DesignBuilder. Indoor temperature set-point, U-value of outer wall, type of window, and degree of ventilation were selected as simulation parameters. In all the simulation cases, heating energy demand was higher than cooling energy demand regardless of the building size. When the lower U-value of the outer wall was applied to account for the thicker insulation layer, heating energy demand was decreased while cooling energy demand was increased. However, it is better to reduce the area of outer wall which is directly exposed to outdoor air because reducing the U-value of the outer wall is not effective in decreasing heating energy demand. Among the four different window types, the double skin window is most favorable because heating energy demand is the lowest. For a fixed infiltration rate, higher ventilation rate resulted in an increased heating energy demand and had minor impact on cooling energy demand. As long as the indoor air quality is acceptable, lower ventilation rate is favorable to reduce the annual energy demand.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.225-231
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• 2016

Glasshouse heating package technologies to improve energy usage efficiency in winter were developed. Heating package was composed of the ground water source heat pump with heating capacity of 105kW, the aluminum multi-layer thermal curtain with six layers of different materials and the root zone local heater with XL pipes of ${\phi}20mm$. Venlo type glasshouse($461m^2$) with the heating package was compared with the same type and area control glasshouse with the light oil boiler, the usual non-woven fabric thermal curtain with respect to the glasshouse inside temperature, relative humidity, crop growth, and heating energy consumption. The results of test in paprika cultivation glasshouses showed that the air temperature inside glasshouse with aluminum multi-layer thermal curtain was maintained $2.2^{\circ}C$ higher than that of control glasshouse in un-heating night time and the temperature in bed with root zone local heating was $4.7^{\circ}C$ higher than that in bed without local heating. Average heating coefficient of performance(COP) of the ground water source heat pump used in paprika cultivation was 3.7 and the glasshouse inside temperature was maintained at $21^{\circ}C$ of heating set up temperature. The heating energy consumptions per 10a were measured at 14,071L of light oil and 364kWh of electric power for the control glasshouse and 35,082kWh for the glasshouse applied heating package. As results, the heating cost of the glasshouse applied heating package was 87 percent lower than that of control glasshouse. The growths of paprika in glasshouses of control and applied heating package did not show any significant difference.

• Journal of Energy Engineering
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• v.22 no.2
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• pp.83-89
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• 2013

Energy consumption is closely related to our lives. As Korea has four seasons, heating and cooling system is considered as essential facilities for the residential buildings. Accordingly, the government has continuously strengthened the design criteria to improve energy for new and existing building to save energy. The most important factor in the energy efficiency analysis for apartment is the heat transmission coefficient, and the value is significantly different as the heating energy amount is greatly different according to the window area ratio versus facade area ratio. Therefore, it is time to conduct continuous set-up for goal to enhance efficiency and restriction on window area ratio versus facade area ratio.

• Journal of Bio-Environment Control
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• v.28 no.1
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• pp.46-54
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• 2019

Experiments of local cooling and heating on crown and root zone of forcing cultivation of strawberry 'Seolhyang' using heat pump and root pruning before planting were conducted. During the daytime, the crown surface temperature of the crown local cooling treatment was maintained at $18{\sim}22^{\circ}C$. This is suitable for flower differentiation, while those of control and root zone local cooling treatment were above $30^{\circ}C$. Budding rate of first flower clusters and initial yields were in the order of crown local cooling, root zone local cooling and control in root pruning plantlet and non pruning plantlet, except for purchase plantlet. Those of root pruning plantlet were higher than those of non pruning plantlet. These trends were evident in the yield of the first flower cluster until February 14, 2018, and the effect of local cooling and root pruning decreased from March 9, 2018. The budding rates of the second flower cluster according to the local cooling and root pruning treatments were not noticeable compared to first flower cluster but showed the same tendency as that of first flower cluster. In the heating experiment, root zone local heating(root zone $20^{\circ}C$+inside greenhouse $5^{\circ}C$) and crown local heating(crown $20^{\circ}C$+inside greenhouse $5^{\circ}C$) saved 59% and 65% of heating fuel, respectively, compared to control(inside greenhouse $9^{\circ}C$). Considering the electric power consumption according to the heat pump operation, the heating costs were reduced by 55% and 61%, respectively.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.11a
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• pp.109-113
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• 1999

겨울철 난방에너지와 여름철 냉방에너지 절감을 위한 자갈축열 태양열 온실의 설계자료를 얻고자 모형 자갈축열층과 이론적 해석을 통하여 축열층의 공기유동성 및 자갈축열층의 축열성능을 분석한 결과를 요약하면 다음과 같다. 1. 압출식으로 공기를 유동시켰을 경우 축열층내 풍속은 0.09-l.50㎧(평균 0.60㎧)범위였으며, 흡인식으로 공기를 유동시켰을 경우 축열층내 풍속은 0.15-0.90㎧(평균 0.46㎧)범위로 평균풍속은 압출식이 높게 나타났으나 축열층 가운데에서는 흠인식이 약 0.06㎧정도 높게 나타났다. 이러한 결과로 볼 때 자갈축열층내 공기순환을 위한 별도의 파이프 매설은 불필요한 것으로 판단된다. 2. 자갈축열층의 공극율이 증가할수록 축열량은 감소하였으며 순환팬 용량과 공극율에 따라 평균 2,133㎉/h-3,243㎉/h 정도 축열량 차이가 있는 것으로 나타났다. 3. 공극율이 0.45인 경우 축열층의 높이가 높을수록 자갈축열층의 온도는 서서히 증가하였으며, 축열층 높이 60cm이하에서는 축열 7시간이후부터는 축열량 변화를 거의 없는 것으로 나타났다. 4. 이러한 결과를 모형축열층에 있어 실험적으로 구해지는 축열 자갈층의 온도 및 축열량과의 비교 검증단계를 거쳐 온실규모에 필요한 적정 축열시스템을 산정할 수 있는 시뮬레이션 프로그램의 기초자료로 활용하고자 한다.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.77-86
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• 2013

This research was carried out to evaluate and raise the energy efficiency of wood frame house. The commercial solution program CE3 (Construction Energy Efficiency Evaluation) was used for simulating the energy consumption in the single-family wood frame house. The results showed that the annual heating energy demand of the house was 160 kWh per 1 $m^2$ floor area. In order to decrease the heating energy demand, the following energy efficiency methods were applied to the simulation : a) simplification of building shape, b) decrease of windows area, c) application of high performance windows (with low thermal transmittance) and d) application of heat recovery ventilator. In case of replacement of the windows with high performance one with thermal transmittance 1 $W/m^2{\cdot}K$, the lowest heating demand of 80 $kWh/m^2{\cdot}a$ was obtained. The best combination of methods, application of high performance windows and heat recovery ventilator, showed heating energy demand 34.5 $kWh/m^2{\cdot}a$.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.876-883
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• 2015

Han-green project, which pursues Korean style post and beam timber house with traditional construction technique of Han-ok, has been carried out in KFRI (Korea Forest Research Institute) since 2006. Recently, the improvement of its building energy performance was studied with energy-saving elements. This study was conducted to provide the insulation details of building envelopes in a post-beam timber house for recent enhanced insulation standards and following effect on building energy performance. The level of thermal transmittance (U-value) values of building envelopes was composed of two stages: present Korean insulation standards and passive house. To evaluate building energy performance, the building airtightness values of two stages was ACH50 = $3.0h^{-1}$ for common domestic timber house constructed recently, and ACH50 = $0.6h^{-1}$ for passive house. Consequently, four cases of the building energy performance according to the combination of U-value with airtightness were evaluated. The test house for evaluation was located in Seoul and its energy performance was evaluated with CE3 commercial building energy simulation program. The result showed that enhanced insulation from level I to II reduced $14kWh/(m^2{\cdot}a)$ of annual heating energy demand regardless of airtightness.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.69-69
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• 2010

현대 건축물에서 건물에너지의 손실은 대부분은 창호를 통하여 유출되어지고 있으며 에너지 절감을 위해서는 창호의 단열성을 향상시켜야한다. 저방사(Low Emissivity) 코팅유리는 건축물의 냉난방비용을 절약할 수 있는 대표적인 건축재료로써 외부에서 유입되는 태양광의 가시광선 영역은 높은 투과율을 가지면서 적외선 영역과 겨울철 실내 난방열을 반사하는 특징을 지니는 박막코팅기술이다. 이 코팅유리는 일반적으로 유전체/금속/유전체 다층박막 구조로 되어있으며, 유전체층은 내구성 증진과 금속층의 반사를 낮추어 투과율이 향상된다. 금속층은 적외선영역의 복사에너지를 반사하는 역할을 하며 전도성이 우수한 Ag 또는 Au, Pt 등을 이용하고 있다. Ag의 경우 산화물기판 위에 증착하였을 경우 island 성장을 하고 이들의 합체는 전기적, 광학적 특성에 큰 영향을 미치게 된다. 본 연구에서는 DC-sputtering법으로 제조된 Ag/glass, Ag/Ta/glass 박막을 제조하고 Ta seeding이 Ag의 전기적, 광학적 성질에 미치는 영향을 관찰하였다. 박막의 표면 미세구조는 FE-SEM(Field Emission Scanning Electron Microscope)과 AFM(Atomic Force Microscope)으로, 표면저항은 4 point probe로 분석하였다. 광투과율은 UV-Vis spectroscopy와 FT-IR로 측정하였으며 측정파장범위는 각각 200~1100nm와 1400~2400nm 이다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.3
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• pp.150-155
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• 2013

Usually, a window tends to have a lower thermal performance, than that of an ordinary wall. This study analyzes the enhancement of thermal performance of a window, when a Thermal Insulation Shutter is installed. The analyses were conducted at the laboratory, and with a full-scale mockup house, and the U-factor and heating load were examined. The laboratory results show that the U-factor increased by approximately 28%, when a Thermal Insulation Shutter was installed. The temperature difference was about $5^{\circ}C$, and this shows that the Thermal Insulation Shutter enhances the thermal performance of the window, when installed. The mockup house was used to calculate the heating load; the heating load was reduced by more than 41%, and shows that the installation of a Thermal Insulation Shutter is an effective way to reduce heating energy consumption.