• Journal of the Korean Solar Energy Society
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• 제32권5호
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• pp.25-30
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• 2012

Ground source heat pumps(GSHPs) are among the most efficient and comfortable heating and cooling technologies currently available, because they use the earth's natural heat to provide heating, cooling, and often, water heating. And Building Integrated Geothermal System(BIGS) is one of GSHPs which install ground heat exchanger(GHE) in energy pile without borehole to save the investment cost. Therefore, the experiment is to evaluate the heating performance of BIGS in Korea. The experimental results indicate that the average heat pump COP and overall system's COP values are approximately 4.4 and 3.0 in one week. This study shows that the BIGS could be used for heating in Korea.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제30권4호
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• pp.159-166
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• 2018

The Korean fenestration energy consumption efficiency rating system only considers thermal performance of the heat transfer coefficient (U-value) and airtightness excluding optical characteristics of the solar heat gain coefficient (SHGC). This study analyzed annual heating and cooling energy requirements on the middle floor of apartment by optical and thermal performance of windows to evaluate the suitability of the rating system. One hundred and twenty-eight windows were analyzed using THERM and WINDOW 7.4, and energy simulation for a reference model of an apartment house facing south was performed using TRNSYS 17. The results showed that window performance was the main factor in the heating and cooling load. The heating load of the reference model was 539 kWh to 2,022 kW, and the cooling load was 376 kWh to 1,443 kWh. The coefficient of determination ($R^2$) of the heating and cooling loads driven from the SHGC were 0.7437 and 0.9869, which are more compatible than those from the U-value, 0.0558 and 0.4781. Therefore, it is not reasonable to evaluate the energy performance of windows using only the U-value, and the Korean fenestration energy consumption efficiency rating system requires a new evaluation standard, including SHGC.

• Journal of the Korean Solar Energy Society
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• 제26권2호
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• pp.95-101
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• 2006

The purpose of this study is to present the simulation results and an overview of the performance assessment of the Ground-Source Heat Pump(GSHF) system. The calculation was performed for two design factors: the spacing between boreholes and the depth of the vertical ground heat exchangers. And the simulation was carried out using the thermal simulation code TRNSYS with new model of water to water heat pump developed by this study. As a result, it was anticipated that the yearly mean COPs of heat pump for heating and cooling are about 3.7 and 5.8 respectively and the heat pump can supply 100% of heating and cooling load all the year around.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제24권6호
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• pp.509-514
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• 2012

In this research, a heat pump system with a heat source network is suggested which utilizes solar heat and ground heat as heat source for cooling and heating. This paper describes the summary of the suggested system and the results of the annual energy simulation. The heating and cooling loads, the electric consumption and the COP were calculated by TRNSYS 16 and evaluated in the cases of different local conditions and different system compositions. In the results, the superiority of the suggested system has been quantitatively evaluated comparing with the conventional heat pump system using one heat source. Furthermore, it was more significant in cold climate, in which the heating COP was 146% increased compared the air source heat pump system, than it in subtropical climate, 119% increased.

• Journal of Bio-Environment Control
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• 제25권4호
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• pp.308-319
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• 2016

In order to set the outdoor weather conditions to be applied to the design standard of the greenhouse heating and cooling system, outdoor air temperature and heating degree-hour for heating design, dry bulb temperature, wet bulb temperature and solar irradiance for cooling design were analyzed and presented. For every region in Korea, we used thirty years from 1981 to 2010 hourly weather data for analysis, which is the current standard of climatological normal provided by KMA. Since the use of standard weather data is limited, design weather conditions were obtained using the entire weather data for 30 years, and the average value of the entire data period was presented as a design standard. The design weather data with exceedance probability of 1, 2.5, and 5% were analyzed by the TAC method, and we presented the distribution map with exceedance probability of 1% for heating and 2.5% for cooling which are recommended by design standards. The changes of maximum heating load, seasonal heating load and maximum cooling load were examined by regions, exceedance probabilities, and setpoint temperatures. The proposed outdoor design conditions can be used not only directly for the greenhouse heating and cooling design, but also for the reinforcement of heating and cooling facilities and the establishment of energy saving measures. Recently, due to the climate change, sweltering heat in summer and abnormal temperature in winter are occurring frequently, so we need to analyze weather data periodically and revise the design standard at least every 10 years cycle.

• Journal of the Korean Solar Energy Society
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• 제31권4호
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• pp.87-94
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• 2011

To develop the solar air heater, prototype of solar heater with test room set up on the roof of test chamber and operation characteristics were examined with solar radiation. Air induced from outside was supplied by a blower and also heated air was supplied to the test chamber(size of 1,000mm(inwidth)*2,000mm(in length)*2,000mm(in depth)) established already for performance. It was clear that almost 30% of solar radiation was converted into effective heating energy at maximum and the highest air temperature was $46^{\circ}C$, and thus solar air heater in winter could be used as an possible alternative heating system in building. Furthermore, heat energy obtained from solar air heater can be applied to regenerate absorber in the solar desiccant cooling system.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.64.1-64.1
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• 2010

In this study, the energy and economic analysis of KIER Zero Energy Solar House (KIER ZeSH) was carried out. KIER ZeSH was designed and constructed in the end of 2009 for the purpose of more than 70% energy self-sufficiency in total load as well as less than 20% of additional construction cost. The several building energy conservation technologies like as super insulation, high performance window, wast heat recovery system, etc and renewable energy system. The renewable heating and cooling system is a kind of solar thermal system combined with geo-source heat pump as a back-up device. The capacity of 3.15kW solar BIPV system was also installed on the roof. The measurement by monitering system of ZeSH was conducted for one year from November 2009 to October 2010. The energy self-sufficiency and economic analysis were conducted based on the this monitering result. As a result, the energy self sufficiency is about 83% which is higher than that of the target and the payback period is 11 years.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제26권10호
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• pp.481-485
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• 2014

Low solar gain glazing should be applied on windows in order to reduce the solar radiation load. In a country where a cooling and a heating load coexist throughout the year, such as in Korea, a high solar gain glazing is need to reduce the heating load, but a low solar gain glazing should be applied to reduce the cooling load. Recently, dynamic windows have been developed for which the solar shading performance switches according to the amount of solar radiation flowing into the indoor space through the glazing, and these have been used in building to solve such problems. The purpose of this research is to analyze the energy performance of the electrochromic glazing for dynamic windows that has been extensively commercialized for office buildings in Incheon and Ulsan through an energy simulation implemented in the eQUEST program.

• Proceedings of the SAREK Conference
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.832-837
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• 2006

This study describes thermal performance of heating and cooling demonstration system using ETSC(Evacuated tubular solar collector) installed at Seo-gu art center of Kwangju. For demonstration study, a reading room with about $331m^2$ was heated and cooled using that system. The demonstration system was consisted of ETSCs, storage tank, hot water supply tank, subsidiary boiler, and subsidiary tank. From January to March in 2006, demonstration test were performed with 4 control mode to find the optimum control condition for solar thermal system. After experiments and analysis, this study found that solar thermal system of control mode IV was corresponded to 78% for the hot water supply and 49% for space heating.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• 제16권4호
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• pp.9-15
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• 2020

In this study, effect of reinforced insulation on heating and cooling loads were studied due to installation of PV panels on factory building roof with a floor area of 12,960 m². For PV panel installation, combination of aluminum, polyurethane, air, polystyrene and steel materials were added to the original roof, which increased thermal insulation performance. Half of the roof were covered with PV panel and the other half without. Temperature and relative humidity were measured for 8 days during summer season for both indoor spaces. PV panel showed the effect of lowering the indoor space temperature by 0.6℃. TRNSYS dynamic simulation showed that with PV panel, cooling load per area is reduced by 1.7 W/m² and heating by 10.0 W/m². PV panels installed on building roof not only generate electricity but also can save energy by reducing cooling and heating loads.