• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.2
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• pp.43-50
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• 2017

The purpose of this study is to develop a control algorithm for outdoor air cooling based on the prediction of cooling load, and to evaluate the building energy saving using outdoor air cooling. Outdoor air conditions such as temperature, humidity, and solar insolation are predicted using forecasted information provided by the meteorological agency, and the building cooling load is predicted from the obtained outdoor air conditions and building characteristics. The air flow rate induced by outdoor air is determined by considering the predicted cooling loads. To evaluate the energy saving, the benchmark building is modeled and simulated using the TRNSYS program. Energy saving by outdoor air cooling using load prediction is found to be around 10% of the total cooling coil load in all locations of Korea. As the allowable minimum indoor temperature is decreased, the total energy saving is increased and approaches close to that of the conventional enthalpy control.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.6
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• pp.574-583
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• 2004

In this study, the operation strategy of the radiant floor cooling is evaluated in terms of indoor environmental conditions and energy consumption through simulations using the TRNSYS comparing the existing cooling operation. The operation strategy during continuously operated for cooling is proposed that a representative room had additional equipments and other rooms were operated with only a radiant floor cooling system and that system and control method for cooling are varied with period while intermittently operated for cooling. Specifically, when there are no people in the room, rooms were operated by only radiant floor cooling system using cooling storage and when people are occupied, rooms were operated by dehumidification and supplementary cooling device with radiant floor cooling system. The results of this study show that proposed operation strategy can stably maintain the set room air temperature and can reduce the energy consumption compared to the existing cooling method during continuously operated for cooling. While intermittently operated for cooling, the difference of set room air temperature by proposed operation strategy does not happen, satisfying comfort standards and the radiant floor cooling can expect to supply stable electric power because of decreasing demand for peak electric power of energy consumption.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.1
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• pp.82-87
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• 2005

The purpose of this study is to suggest the characteristics and actual state of energy consumption by the analysis of energy consumption data in an office building. This study examines and analyzes daily and monthly energy consumption of an office building located in Seoul, Korea regarding type of load and business classification within a building. The results are as follows. 1) Energy consumption of office building for each type of load show similar consumption patterns, regardless of seasons such as cooling period and heating period. 2) Out of all annual energy consumption, consumption for lighting took about $43\;\%,$ general electric Power about $23\;\%,$ emergency power $25\;\%,$ computer center $5\;\%$ and cooling power $4\;\%,$ showing that the consumption for lighting was highest, and the percentage of energy consumption for cooling power for operation of cooling facilities took the lowest percentage. 3) Annual gas consumption used for heating and hot water supply were $38,\;36\;\%$ for officetel and office respectively, and $26\;\%$ for arcade. 4) Electricity consumptions used for cooling power for each use of building, office and officetel recorded in July and August of cooling seasons. Even though it shows different patterns for each month, energy consumption showed unique pattern throughout the cooling seasons.

• KIEAE Journal
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• v.4 no.4
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• pp.19-26
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• 2004

The purpose of this study was to evaluate the thermal environment of present state and energy consumption and to verify the improvement of energy performance applying free cooling in 5ESS-2000 telecommunication equipment room. Analysis program is used the DOE-2.1E and commercial CFD code, Star-CD. The results of the simulation show that free cooling could reduce 42.1% of cooling energy, increase 48.5% of heating energy because introduced outdoor air must heating and humidification. Therefore free cooling could reduce yearly 34,609.9 kWh of heating and cooling energy and this is reaching to 21.6% of total energy.

• Journal of the Korean Solar Energy Society
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• v.21 no.4
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• pp.1-11
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• 2001

The authors carried out a study on the cooling effect of radiant cooling system using the metallic lightweight radiator for cooling energy saying in building. The radiant cooling performance was examined, analyzed, and presented through the case study. In this study, the cooling effect of various factors was analyzed, especially in a thin plate above the roof. These numerical results can be used as the basic design data for application of radiant cooling system. As a result of these researches, the system was verified to be an available cooling energy sources for improvement of indoor environment in summer. Finally, to complete the system can be suitable for Korean climate conditions, experimental study should be performed on the basis of these results.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.33-38
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• 2009

Energy loss from windows accounts for large scores of heating and cooling loads also in energy saving apartments that is reduced over 30% of total energy consumption. Movable reflective insulations, insulation shutters, blinds, insulated shades are used to reduce energy loads from windows. In this study, energy saving performance of insulated shades was simulated by control methods. According to installation of insulated shades, heating loads were decreased about $10.5{\sim}11.3%$, and cooling loads are decreased about $11.0{\sim}15.5%$ on an energy saving apartment. The heating peak load was reduced about 9.5% by insulated shades, but the cooling peak load is hardly ever decreased. Because in the condition of cooling peak load, latent cooling loads accounts for large score of cooling loads. Difference of the energy loads by a schedule control method and an outdoor detection control was no more than 5% for a base model. In the case of insulated shades with automatic control system, simple time schedule control system would be more efficient than outdoor detection control system that should use several sensors.

• Journal of the Korean Institute of Gas
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• v.10 no.4 s.33
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• pp.34-40
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• 2006

This paper provides a fusion technology between a district cooling energy system and an environment conservation policy based on the energy savings and reusable cold energy resources. The district heating and cooling systems are very effective ways for an energy saving, a cost reduction and a safety control. It is necessary to equalize the energy savings and an environmental preservation policy for an improved human lift. A gasification process of a liquefied natural gas, cooling water from deep seawater and an ice water thermal storage system may produce a cold energy. A district cooling system is used to cool an apartment, office buildings and factory facilities with a cooling energy supply pipeline. LNG cooling energy will switch a conventional air-conditioning system, which is operated by on electrical energy and a Freon refrigerant. Coincident with significant clean energy and operating cost savings, LNG cold energy system owen radical reductions in an air-borne pollutant, $CO_2$ and the release of environmentally harmful refrigerants compared with that of the conventional air-conditioning system. This study provides useful information on the fusion technology of a LNG cold energy usage and energy savings, and environmental conservation.

• KIEAE Journal
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• v.14 no.2
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• pp.11-19
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• 2014

Building energy consumption takes up almost 25% of the total energy consumption. Therefore, diversified ways, such as improving wall and window insulation, have been considered to reduce building energy consumption. Recently, green roof system has been explored as an effective alternative for dealing with reducing heating and cooling energy, thermal island effect and improving water quality. However, recent studies regarding a green roof system have only focused on building energy reduction without considering the applied usage, location, and story of the green roof system. Therefore, this study pays attention to the heating and cooling energy in relation to the applied usage, location, and story of a green roof system for investigating its impact on energy reduction. The result of simulations show that the reduction in heating energy consumption is higher when applied to Cherwon-gun province which has a continental climate condition, compared to the city of Busan that is distinguished by its warm climate. Cooling energy saving turns out to be higher when the green roof system is applied to Busan in comparison with Cherwon. As for the applied usage or function of the building, residential space acquires the highest heating and cooling energy saving effect rather than commerce, educational or office space because of HVAC's running time based on usage. When it comes to the story of the green roof, both heating and cooling energy saving become the highest when the green roof is applied to single-storied buildings. The reason is that single story building is affected by the ground largely. Generally, the variations of heating energy consumption are larger than the cooling energy consumption. The outcome of the simulations, when a green roof system is applied, indicates that the energy consumption reduction rate is dynamically responding to the applied usage, location, and story. Therefore, these factors should be counted closely for maximizing the reduction of energy consumption through green roof systems.

• Journal of the Korean Institute of Gas
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• v.7 no.4 s.21
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• pp.36-43
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• 2003

This paper provides the possibility of the district cooling system by using a LNG cold thermal energy. A liquefied natural gas provides a plenty of cooling source energy during a gasification of a liquefied natural gas. In recent, an ice thermal storage system is used for cooling a building, and a deep water source cooling system has been introduced as a district cooling system in which is used to cool the office towers and other large buildings in old and new downtown. LNG cooling energy refers to the reuse of a large body of naturally cold fluids as a heat sink for process and comfort space cooling as an alternative of conventional, refrigerant based cooling systems. Coincident with significant clean energy and operating cost savings, LNG cold energy cooling system offers radical reductions in air-borne pollutants and the release of environmentally harmful refrigerants in comparison to the conventional air-conditioning system. This study provides useful information on the basic design concepts, environmental considerations and performance related to the application of LNG cold thermal energy.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.48-54
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• 2015

In a centralized cooling plant, precise mechanical design and control strategy are required for peak and partial cooling load management. Otherwise, it will lead to low efficiency of cooling system and energy loss due to low partial load efficiency. The purpose of this paper is to enhance energy performance of the centralized cooling plant by controlling flow system in an industrial building using measured data and energy performance simulation program. The simulation results show that the proposed flow control can cut down annual electric power consumption by about 17% compared with the conventional cooling system.