• Title/Summary/Keyword: Thermal response of building

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A Field Survey of Thermal Comfort in Office Building with Thermal Environment Standard (온열환경기준에 따른 여름철 사무실의 열쾌적성 평가)

  • Kong, Hyo-Joo;Yun, Geun-Young;Kim, Jeong-Tai
    • KIEAE Journal
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    • v.11 no.3
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    • pp.37-42
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    • 2011
  • This study aims to analyze the field survey of thermal comfort in office building with national thermal environment standard. Internal and external temperatures were measured at ten minute intervals and compared in accordance with the national standard for thermal environment. Sixty two workers filled in the questionnaire survey forms five times a day for 40 days. Field monitoring of offices in Seoul, Korea were conducted from 20 July to 28 August. Result for the comfort temperature was set a $26.30^{\circ}C$. This indicates that the 26 degree is reliable for the Korean standard. Indoor temperature standard can reduce energy use by air-conditioned buildings and the temperature would be offer comfort to occupants.

An application to HVAC control system based on occupants' thermal response in office buildings (공조제어 적용을 위한 재실자 온열반응 데이터의 유효성 분석에 관한 연구)

  • Han, Hyesim;Kim, Jonghun;Jeong, Hakgeun;Jang, Cheol-Yong
    • KIEAE Journal
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    • v.14 no.4
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    • pp.111-117
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    • 2014
  • In South Korea, the government has recently enforced regulations associated with buildings. Temperature restriction in indoor environment is one of the common ways of energy reduction in order not to dissipate heating and cooling energy; however the people who are in restricted temperature feels uncomfortable. Furthermore, occupants cannot feel the same thermal sensation even they are in the same place. For the reason, occupants should express their thermal sensation and HVAC system should be able to apply their demand. It is proved by an adaptive principle. The adaptive model means that people react in ways which tend to restore their comfort, when change occurs such as to produce discomfort. In order to design HVAC control strategies based on adaptive model, we designated an existing office building as a reference building to gather data from actual field. Furthermore, we gathered occupants' thermal sensation and clothing insulation in real-time. We filtered the data with Kalman's filter method. The data was reasonable when there is an alarm messages for asking questionnaire. The response ratio were different in occupants' thermal condition. In conclusion, the filtered occupants' thermal sensation can be used as a real time HVAC control and input value of HVAC control.

Dense Thermal 3D Point Cloud Generation of Building Envelope by Drone-based Photogrammetry

  • Jo, Hyeon Jeong;Jang, Yeong Jae;Lee, Jae Wang;Oh, Jae Hong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.2
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    • pp.73-79
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    • 2021
  • Recently there are growing interests on the energy conservation and emission reduction. In the fields of architecture and civil engineering, the energy monitoring of structures is required to response the energy issues. In perspective of thermal monitoring, thermal images gains popularity for their rich visual information. With the rapid development of the drone platform, aerial thermal images acquired using drone can be used to monitor not only a part of structure, but wider coverage. In addition, the stereo photogrammetric process is expected to generate 3D point cloud with thermal information. However thermal images show very poor in resolution with narrow field of view that limit the use of drone-based thermal photogrammety. In the study, we aimed to generate 3D thermal point cloud using visible and thermal images. The visible images show high spatial resolution being able to generate precise and dense point clouds. Then we extract thermal information from thermal images to assign them onto the point clouds by precisely establishing photogrammetric collinearity between the point clouds and thermal images. From the experiment, we successfully generate dense 3D thermal point cloud showing 3D thermal distribution over the building structure.

Post Occupancy Evaluation for Office Building with An Underfloor Air Distribution System (바닥공조 시스템이 적용된 사무공간의 거주후 성능평가)

  • Yoon, Seong-Hoon;Jang, Hyang-In;Jung, Hae-Kwon;Choi, Sun-Kyu;Yu, Ki-Hyung
    • Journal of the Korean Solar Energy Society
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    • v.31 no.6
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    • pp.78-85
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    • 2011
  • In this study, an underfloor air distribution(UFAD) system installed on the S. office building was evaluated for its indoor environmental quality performance. Field measurement and survey were conducted for the overall POE(Post Occupied Evaluation). PMV(including temperature, humidity, air velocity and globe temperature) and several environmental components were measured while thermal comfort, thermal sensation, acoustical environment and others. were investigated through survey. Except for the direct upper part of the air supply diffuser on the floor, the indoor velocity was less than 0.25m/s, which has been suggested by ASHRAES tandard 55 as the limit for thermal comfort. MRT of the perimeter zone of the room showed a higher value than that in the interior because of the introduced solar radiation through the building envelope. PMV was generally maintained in the range of thermal comfort (from -0.5 to +0.5), though it weighted to the warm side. It was reported to have 61% positive response on thermal comfort and 55% on neutral thermal sensation. The results of each survey item showed some gender-based differences. Specifically, female respondents had higher degree of dissatisfaction with indoor air cleanness and acoustical privacy. The working surface showed more than 400 lux and the equivalent noise level showed less than 50 dB(A). In conclusion, the results of the measurement and survey showed good agreement. Indoor environmental quality of the subject office room where the UFAD system was installed showed an overall excellent performance.

A Study on the Surface Temperature Change of Building Applied with Thermal Insulation Waterproofing Material During Summer (하절기 차열성능을 갖는 방수재의 적용에 따른 건축물 표면온도 변화추이 연구)

  • Kim, Dong-Bum;Park, Jin-Sang;Choi, Su-Young;Park, Jae-Hong;Kim, Byoung-Il;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.45-46
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    • 2017
  • As the environment and energy problems such as global climate change (global warming, urban heat island phenomenon) and energy depletion have come to the fore, the construction and waterproofing industry are responding more critically to the demands of global green technology and are employing more eco-friendly technologies as of recent. In this study, the application of the waterproofing material with thermal response performance in construction buildings was investigated to confirm whether the thermal performance is being properly secured by the change of the surface temperature. Experimental results showed that the surface temperature difference between before and after the application is at least 19.8℃ at the maximum 26.3℃. When the degradation rate is converted, the degradation effect of about 40% on average was confirmed.

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Analysis of Supply Airflow Control by a Stratified Thermal Model in a VAV System

  • Kim, Seo-Young;Moon, Jeong-Woo;Cho, Hyung-Hee
    • International Journal of Air-Conditioning and Refrigeration
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    • v.9 no.3
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    • pp.46-56
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    • 2001
  • The present study concerns the numerical simulation of a supply airflow control in a variable air volume (VAY) system. A stratified thermal model (multi-zone model) is suggested to predict a local thermal response of an air-conditioned space. The effects of various thermal parameters such as the cooling system capacity, the thermal mass of an air-conditioned space, the time delay of thermal effect, and the building envelope heat transmission are investigated. Further, the influence of control parameters such as the supply air temperature, the PI control factor and the thermostat location on a VAV system is quantitatively delineated. The results obtained show that the previous homogeneous lumped thermal model (single zone model) may overestimate the time taken to the set point temperature. It is also found that there exist the appropriate ranges of the control parameters for the optimal airflow control of the VAV system.

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A Study on the Evaluation Methods of Indoor Thermal Environment in Office Building (사무소건축의 실내온열환경 평가방법에 대한 연구)

  • Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.6 no.4
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    • pp.355-359
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    • 2003
  • 1. The objective of this paper is to investigate the indoor environment from the viewpoint of interaction between physical environment and the human responses. 2. A continuous measurement has been carried out for 1 year and distribution of variables have been measured for 1 day. 3. The attitude of workers was investigated by a questionnaire. 4. As the result, average luminance represented more than 800-1800 lx in the office, in contrast with less than 1000 lx in the encourage luminance of an office. 5. There was a significant difference of the occupants' response to the light environment between the neighboring environments. 6. Measured thermal conditions are on the edge of the ASHRAE comfort envelope in summer, and in the neighborhood of the lower dry limit of the envelope in spring.

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Development of Thermal Type Fluid Level Transmitter for Water Level Measurement of Containment Building in Nuclear Power Plant (원자력 발전소 격납 건물의 수위 측정을 위한 열식 레벨 측정기 개발)

  • Yoon, Joon-Yong;Seong, Nak-Won;Lee, Chul-Ho
    • 유체기계공업학회:학술대회논문집
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    • 2001.11a
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    • pp.404-410
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    • 2001
  • A new thermal type fluid level transmitter was designed and tested at the HITROL R&D institute. The relation of heat transfer and electric resistance was adopted as an operation principle. The length of a fabricated level transmitter was two meters and a water under normal temperature was used as a working fluid for the experiment Finally, the new product could have a high precision, acceptable accuracy and reasonable response time. Foreign-made level transmitter of this type is under in use for measuring water level of containment building in nuclear power plants so far. It is expected that new product will substitute it.

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Thermal Performance Evaluation of The Window Film Insulation for Building Energy Savings (건물에너지 절감을 위한 열차단 필름의 성능 평가)

  • Nam, Jung-Woo;Won, Jong-Seo
    • 한국태양에너지학회:학술대회논문집
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    • 2008.11a
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    • pp.75-80
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    • 2008
  • Recently, Energy savings in buildings has received much attention in response to the increased needs for global warming and better comforts of the occupants in apartment housing. This study proposes the method which uses the sun control window film to reduce the cooling load and heating load improving the thermal performance of the building and it improves an energy efficiency. The film which used in actual measurement has a low shading coefficient and a solar energy transmission. so we measured the surface temperature of the triple Low-e glazing system used and inside temperature according to the change of outside temperature and solar energy to study thermal performance evaluation. As a result, it was helpful to use window film insulation to reduce inside temperature in summer and to keep room warm in winter.

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Temperature distribution in a full-scale steel framed building subject to a natural fire

  • Wald, Frantisek;Chladna, Magdalena;Moore, David;Santiago, Aldina;Lennon, Tom
    • Steel and Composite Structures
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    • v.6 no.2
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    • pp.159-182
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    • 2006
  • Current fire design codes for determining the temperature within the structural elements that form part of a complete building are based on isolated member tests subjected to the standard fire. However, the standard time-temperature response bears little relation to real fires and doesn't include the effects of differing ventilation conditions or the influence of the thermal properties of compartment linings. The degree to which temperature uniformity is present in real compartments is not addressed and direct flame impingement may also have an influence, which is not considered. It is clear that the complex thermal environmental that occurs within a real building subject to a natural fire can only be addressed using realistic full-scale tests. To study global structural and thermal behaviour, a research project was conducted on the eight storey steel frame building at the Building Research Establishment's Cardington laboratory. The fire compartment was 11 m long by 7 m wide. A fire load of $40kg/m^2$ was applied together with 100% of the permanent actions and variable permanent actions and 56% of live actions. This paper summarises the experimental programme and presents the time-temperature development in the fire compartment and in the main supporting structural elements. Comparisons are also made between the test results and the temperatures predicted by the structural fire Eurocodes.