• Title/Summary/Keyword: Thermal-Comfort

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A Study on the Optimization of Heating and Cooling System in University Campus (대학 캠퍼스 냉·난방시스템 최적화 방안 연구)

  • Park, So-Yeon;Park, Hyo-Soon;Lee, Sang-Hyeok;Kim, Ji-Yeon;Hong, Sung-Hee
    • KIEAE Journal
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    • v.10 no.6
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    • pp.139-144
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    • 2010
  • The demands are increasing for the efficient heating and cooling system and thermal comfort environment because of changes in climate and environment, and deterioration of buildings and facilities can cause education budget to increase. So the study to apply heating and cooling system to university is urgently needed to improve an optimum energy saving system, educational environment and convenience of maintenance. For this reason, we selected a university campus in Seoul then came to understand the current situation and found some problems. We drew alternatives from comparative analysis of them. It selects representative building and carries out economic analysis to evaluate characteristics of energy consumption and economics on each type of heating and cooling system. As a result we drew the optimum system from those processes as previously stated. We studied 3 available systems, absorption chiller, EHP(Electric Heat Pump) and GHP(Gas Engine Heat Pump). According to LCC analysis suppose that the value of EHP is 1, it came out that the value of absorption chiller is 1.5 and the value of GHP is 2.2. This study, suggesting the optimum heating and cooling system, will support educational and research activities furthermore effect to maximize energy efficiency. Ultimately it is expected that it will contribute to make eco-friendly Green Campus.

Checklist and Design Recommendations for the Interiors of Korean, Eco-healthy Childcare Facilities (우리나라 영유아 보육시설의 친환경 실내를 위한 체크리스트와 디자인안 제안)

  • Chun, Jin Hie
    • KIEAE Journal
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    • v.10 no.6
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    • pp.105-114
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    • 2010
  • As children are known to touch and chew everything, green cleaning procedures are an important step in preventing children from ingesting harmful toxins. The objectives of this study are to develop a new, self-evaluation checklist and to suggest design recommendations which comply with easy, adaptable, economical ways to improve the eco-friendly indoor environment of Korean childcare facilities. The information compiled during this study was collected through literature review and internet surveys1) from July, 2009 to February, 2010. The results of this study show that the current Korean childcare accreditation system and practices emphasize clean building interiors, policies for sanitation and cleanliness, and control of humidity and lighting. On the other hand, the information provided by green-building rating systems from GBCC, LEED, and GBTool offers additional and comparative details regarding indoor environment quality and standards regarding the IAQ performance and management plan, ventilation and thermal comfort systems, views from windows, acoustics, and lighting. In conclusion, this document provides an appropriate and easy-to-follow, self-evaluation checklist composed of eight criteria and 51 practical items. This study also provides the design recommendations composed of 27 practical ideas focusing on interior elements. Both the checklist and design recommendations I have suggested can be a post-occupancy tool for evaluating eco-healthy facility standards as well as tips for continuing to maintain eco-healthy childcare facilities.

The study of defrosting performance on automobile Windshield through different injection angle (Different injection angle에 따른 자동차 전면 유리 제상성능 연구)

  • Kang, Hyu-Goo;Lee, Kum-Bae;Kader, Md. Faisal;Oh, Gyu-Nam
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2454-2459
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    • 2008
  • The objective of this paper is to find out the most effective injection angle for the purpose of deicing through SC/Tetra, a commonly used CFD software. Nowadays, vehicles are developed giving priority to an improved interior which emphasizes a pleasant environment and thermal comfort without decreasing the basic performance. Clear visibility is one of the most important phenomenon. The primary factors which affect the efficiency of deicing are 3D geometry of Defrost Nozzle, the inlet velocity and temperature of the flow and the injection angle. However in this paper, all these parameters are optimized by changing the injection angle. A wide range of injection angle from 5 degree to 50 degree have been considered for analysis. A very good defrosting performance has been achieved with 45 degree injection angle which can satisfy the condition of NHTSA.

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Numerical Study on Control Factors of Defrosting Performance for Automobile Windshield Glass in Winter (수치해석을 통한 자동차 전면유리 제상성능 제어인자 연구)

  • Youn, Young-Muk;Kader, Md. Faisal;Lee, Kum-Bae;Jun, Yong-Du
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.12
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    • pp.789-794
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    • 2008
  • Recently, much attention has been paid in the field of defrosting because clear windshield in vehicle without effecting the thermal comfort is realized essentially. Then in winter, defrosting performance is one of the important factors in vehicle design to make certain driver's view. In this study, the velocity profile, temperature distribution and frost melting pattern on the windshield screen have been predicted in three dimensional geometry of an automobile interior. Numerical analyses predict a detailed description of fluid flow and temperature patterns on the inside windshield screen, utilizing the flow through defroster nozzle. Numerical prediction established a good defrosting performance with the standard distance ratio and the defroster nozzle angle ranging from $30^{\circ}$ to $40^{\circ}$, which satisfy the condition of National Highway Traffic Safety Administration (NHTSA) completely.

A Comparison of Heating Control Characteristics by Temperature Sensing Methods for Thermostatic Valves with the Proportional Control Mode (비례제어식 자동온도조절기의 온도감지방식별 난방제어 특성 비교)

  • Kim, Yong-Ki;Lee, Tae-Won;Kang, Sung-Ju
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.161-166
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    • 2007
  • Various thermostatic valves have been used widely in Korea for conservation of heating energy and enhancement of thermal comfort in residential buildings. But heating control performances of thermostatic valves extensively vary with the design and operational conditions of the heating system, climate condition and others. An experimental method was carried out in this study to analyze heating control characteristics by temperature sensing methods of thermostatic valves for various parameters, such as supply temperatures and flow rate of hot water, the position of room thermostats and outdoor air temperatures. As a result, the heat flow rate per day of S-Valve($34^{\circ}C$-Type) of water temperature sensing method was liked that of C-Valve of indoor air temperature sensing method with stage 3.3 of room thermostat in case supply temperature of hot water was $45^{\circ}C$, flow rate was 1.3 L/min and outdoor air temperature was $7.8^{\circ}C$.

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Operating Characteristics of the Flow Control Valve for the Radiant Heating System (복사난방용 유량조절 밸브의 작동특성 연구)

  • Pyo, Jin-Soo;Jang, Choon-Soo;Choi, Kwang-Suk;Kim, Youn-Jea
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.552-557
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    • 2007
  • Due to the recent improvement of living standard of residential buildings, the requirements of the thermal comfort and energy saving in heating system have been raised. The radiant floor heating system has been widely used as a residential heating method, which has been modernized to use hot water running into the tubes embedded in the floor structure. The uniform flow distribution is very important factor for a radiant floor heating system such as a blood vessel system in human body. Therefore, it is necessary to investigate the operating characteristics to develop an optimal radiant floor heating system. In this study, numerical analyses were carried out, using a commercial CFD code, FLUENT, to obtain the velocity distribution under steady, three-dimensional, standard k-$\varepsilon$ model and no-slip condition. Results are graphically depicted with various parameters.

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Why Healthy Workplaces Matter

  • Best, Robert S.
    • International Journal of High-Rise Buildings
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    • v.6 no.4
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    • pp.297-300
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    • 2017
  • Employers are realizing that workplaces have an immense impact on productivity. And, because people typically represent about 90% of a company's costs, even a slight improvement in productivity hits the bottom-line in a very big way. The focus is shifting away from saving money by reducing space needs or cutting energy requirements, and moving toward making the workplace friendlier and healthier. What is a healthy workplace, exactly? The answer should be clear by now. Mountains of research have expounded on this very topic, and then news outlets cover the latest discoveres ad infinitum. The problem is, research is rather dense, while the news isn't comprehensive. Office managers trying to improve workplace wellness want neither a 55-page report nor a half dozen articles to convince their landlord that their space can do better. Recognizing this gap, Harvard researchers have released a concise-yet-complete list of healthy building features. Here, we're sharing these nine features with a few insights of our own on the value of being healthy and productive. Find out: ${\bullet}$ What makes a healthy building and why is it so important ${\bullet}$ How to improve the health of your own office ${\bullet}$ What happens for your people and your bottom line when you make health a priority.

A Field Measuring Study on the Thermal Environment of Human Surrounding in the Classroom Equipped with Ceiling Unit (천장형 유닛을 설치한 교실 내의 인체 주변 온열환경에 관한 실측연구)

  • Cho Sung-Woo;Im Young-Bin;Lee Kyung-Hee
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.3
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    • pp.240-246
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    • 2006
  • This paper performed to investigate on vertical temperature distribution, effective draft temperature (ETD) and PMV (Predicted Mean Vote) in the classroom, which is located YangSan city (Kyungsangnam-Do), Korea, is equipped with ceiling unit. The vertical temperature difference between F.L+10 cm (ankle) and F.L+120 cm (neck) of a measuring point which is adjacent corridor in the classroom showed about $1^{\circ}C$ but of measuring point which is adjacent outdoor expressed up to $4^{\circ}C$, The effective draft temperature (ETD) is -2.3 and -0.52 and 0.67 at near ceiling unit but is 1.2 and 3.3 at far from ceiling unit. The PMV of total classroom showed the range of 'Cold' and 'Slightly Cold.' Therefore, to achieve comfort condition in the classroom is equipped with ceiling unit, the location of ceiling unit and discharge angle and discharge distance from ceiling unit are very important elements.

Development of the TRNSYS Simulation Modules for System Air-Conditioner and Its' Verification (TRNSYS 시뮬레이션을 통한 시스템 에어컨의 구현과 타당성 검증)

  • Ki, Hyun-Seung;Hong, In-Pyo;Park, Jun-Won;Kang, Ki-Nam;Song, Doo-Sam
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.4
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    • pp.315-322
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    • 2012
  • In these days, importance of HVAC system in office building is steadily growing in terms of thermal comfort and energy savings. As a energy efficient heating and cooling system, system air-conditioner which can be controlled distinctly and has a high COP is more widely adopted nowadays. However, the features and advantages of system air-conditioner were not reported well because system air-conditioner did not describe yet by conventional simulation methods such as TRNSYS, e-Quest, Energyplus, etc. In this study, by using the TRNSYS program which is able to show module implementation and building energy consumption analysis, system air-conditioner module will be proposed and validated through comparison between the simulation results and measurement results.

A Study on Design of Movable Horizontal Shading Device for Office Building (사무소건물의 가동식 수평차양에 대한 연구)

  • Kim, Mi-Hyun;Suh, Seung-Jik
    • Journal of the Korean Solar Energy Society
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    • v.28 no.2
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    • pp.50-57
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    • 2008
  • This study intends to evaluate the effect on indoor environment(annual thermal load, sunshine)by the application of the movable horizontal shading device on summer and winter season. For these purpose, we supposed the models which are composed of the several horizontal shading devices. Then we analyzed the simulation using the IES5.5.1 and Seoul weather data. The results of this study are as follows: 1) The proper length, angle of horizontal shading device is 2.1m, 28 degree, respectively. 2) The decreasing rate of the annual load of the Movable Horizontal Shading Model(MHSM) in comparison with the No Shading Model(NSM) & Conventional Horizontal Shading Model(CHSM) is 31.11%, 6.63% respectively. 3) The decrease of sunshine of the MHSM on summer season is effective the alleviation of visual displeasure. On the other hand, the increase of sunshine of the MHSM on winter season is effective the psychological comfort. Further study is to be required the sensitivity analysis on the various shading length for the realistic proper shading length.