• Wind and Structures
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• v.11 no.1
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• pp.51-70
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• 2008

CFD is applied to evaluate pedestrian wind comfort at outdoor platforms in a high-rise apartment building. Model validation is focused on generic building sub-configurations that are obtained by decomposition of the actual complex building geometry. The comfort study is performed during the design stage, which allows structural design changes to be made for wind comfort improvement. Preliminary simulations are performed to determine the effect of different design modifications. A full wind comfort assessment study is conducted for the final design. Structural remedial measures for this building, aimed at reducing pressure short-circuiting, appear to be successful in bringing the discomfort probability estimates down to acceptable levels. Finally, the importance of one of the main sources of uncertainty in this type of wind comfort studies is illustrated. It is shown that the uncertainty about the terrain roughness classification can strongly influence the outcome of wind comfort studies and can lead to wrong decisions. This problem is present to the same extent in both wind tunnel and CFD wind comfort studies when applying the same particular procedure for terrain relation contributions as used in this paper.

• Advances in Energy Research
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• v.5 no.1
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• pp.65-77
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• 2017

The latest UK Climate Projections (UKCP09) show that mean daily temperatures will increase everywhere in the United Kingdom. This will significantly affect the thermal and energy performance of the current building stock. This study examines an institutional fully glazed building and looks into the changes in the cooling loads and thermal comfort of the occupants during the occupied hours of the non-heating period. Furthermore, it investigates the effect of relative humidity (RH) on thermal comfort. The Design Summer Year (DSY) 2003 for London Heathrow has been used as a baseline for this study and the DSY 2050s High Emissions scenario was used to examine the performance of the building under future weather conditions. Results show a 21% increase of the cooling loads between the two examined scenarios. Thermal comfort appears to be slightly improved during the months of May and September and marginally worsen during the summer months. Results of the simulation show that a relative humidity control at 40% can improve the thermal comfort for 53% of the occupied hours. A comparison of the thermal comfort performance during the hottest week of the year, shows that when the relative humidity control is applied thermal comfort performance of the 2050s is similar or better compared to the thermal comfort performance under the baseline.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.2
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• pp.11-21
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• 1999

This objective of this paper is to investigate the evaluation and indiction of human thermal comfort in building environment. The issue of defining the boundaries of acceptable thermal comfort conditions in buildings and urban may have significant implication for building design and also may have urban design by climate considerations. And then it is to apply the thermal comfort condition to environmental design by using passive methods in Korea. Since 1920. architects have conducted studies to measure thermal comfort in houses under hot and humid conditions, while industrial hygienists have studied the effects of temperature and humidity on the performance of factory workers. Thermal comfort can be influenced by many variables. This paper conducted to review the previous researches and the human heat balance equation, and to analyse in order to reveal the meaning and usage of the thermal comfort index in two traditional essays, Fanger's PMV and Gagge's ET* Their comfort indexes compared with each other. They were based on human heat balance equation and psychological and physiological responses in the laboratory tests. The researchers and the architectural engineers using thermal comfort index shall be careful in decided the use of indexes and be necessary to recognize the value concept of the design criteria for thermal comfort. Therefore, The opinion of the authors is that different comfort standards have to apply for each building and urban with different climatic conditions.

• Advances in environmental research
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• v.3 no.3
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• pp.253-281
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• 2014

The quest for enhanced thermal comfort for dwellings encompasses the holistic utilization of improved building fabric, impact of weather variation and amongst passive cooling design consideration the provision of appropriate ventilation and shading strategy. Whilst thermal comfort is prime to dwellings considerations, limited research has been done in this area with the attention focused mostly on non-dwellings. This paper examines the current and future thermal comfort implications of four different standard construction specifications which show a progressive increase in thermal mass and airtightness and is underpinned by the newly developed CIBSE adaptive thermal comfort method for assessing the risk of overheating in naturally ventilated dwellings. Interactive investigation on the impact of building fabric variation, natural ventilation scenarios, external shading and varying occupants' characteristics to analyse dwellings thermal comfort based on non-heating season of current and future weather patterns of London and Birmingham is conducted. The overheating analysis focus on the whole building and individual zones. The findings from the thermal analysis simulation are illustrated graphically coupled with statistical analysis of data collected from the simulation. The results indicate that, judicious integrated approach of improved design options could substantially reduce the operating temperatures in dwellings and enhance thermal comfort.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.3
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• pp.206-217
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• 1994

In this study, indoor thermal parameters were measured to investigate the characteristics of thermal environments and 212 occupants were questioned to evaluate Korean thermal comfort in office building in summer. Thermal and comfort sensations were estimated using PMV(Predicted Mean Vote) and ET* (New Effective Temperature) which are most widely used nowadays. Comparing this experimental result with international standards and that of other research, Korean thermal responses were discussed. It was found that TSV(Thermal Sensation Vote) is more sensitive than PMV to the variation of temperature and that the measured percentage of dissatisfied is higher than PPD(Predicted Percentage of Dissatisfied) in real office building environments. By regression analysis, the following regression equation has been obtained: TSV=0.461ET*-11.808 and neutral temperature is $25.6^{\circ}C$ in this case. Thermal comfort range based on 80% satisfaction is also $24.0{\sim}26.8^{\circ}C$, which is about $1^{\circ}C$ higher than that of ANSI/ASHRAE Standard.

• Journal of the Korean Solar Energy Society
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• v.38 no.6
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• pp.1-14
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• 2018

The shading device on the window of the building can be an passive solution to reduce the cooling load and lighting energy, as well as improving the indoor comfort. It is also an architectural element that must be considered for building energy-efficient buildings such as eco-buildings and zero-energy buildings. However, due to various building environments and various shading devices, the installation of excessive shade may lead to the risk of losing the effectiveness of windows. In this study, we propose a method for optimal automatic control of shading device and evaluate its effectiveness by energy analysis of several shading devices.

• 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.2
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• pp.310-318
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• 1995

In this study, indoor thermal parameters were measured to investigate the characteristics of thermal environments and 138 occupants were questioned to evaluate Korean thermal comfort in office building in winter. Thermal sensation was estimated by using PMV(Predicted Mean Vote) and ET*(New Effective Temperature) indices. Comparing present experimental result with international standards and that of other research, Korean thermal responses were discussed. Seasonal difference between summer and winter was also discussed. It was found that TSV(Thermal Sensation Vote) is more sensitive than PMV to the variation of temperature and that the measured percentage of dissatisfied is higher than PPD(Predicted Percentage of Dissatisfied) in real office building environments. By regression analysis, the following regression equation has been obtained; TSV=0.432ET*-8.814 and neutral temperature is $20.4^{\circ}C$ in this case. Thermal comfort range based on 80% satisfaction is also $19.4{\sim}22.4^{\circ}C$.

• KIEAE Journal
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• v.15 no.6
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• pp.101-109
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• 2015

Purpose: Glazing and shading devices influence a lot on the thermal and visual environment in office buildings. Solar heat and daylight are contrary concept, therefore proper arrangement of thermal and optical performance is needed when designing a glazing and shading devices. The purpose of this study is to examine the conditions of the glazing and shading devices available for promoting the reduction of cooling loads + lighting loads and the improvement in thermal comfort and visual comfort for the summer season in an office building installed with venetian blind. Method: This study established 12 simulation cases which have different glazings and the positions of venetian blind for evaluating different thermal and optical performance. And by using EnergyPlus v8.1 and Window v7.2 program, we quantitatively analyzed cooling loads + lighting loads, thermal comfort and visual comfort in an office building installed with the glazing and shading devices. Result: Consequently, Case 9(Double Low-E+Exterior Blind) is the best arrangement of solar heat gain and daylight influx, thereby becomes the most excellent case of reducing cooling+lighting loads(46.8%) and simultaneously becomes the enhancement case in thermal comfort. Also, DGI(Daylight glare index) under clear sky conditions in summer was evaluated to be 19.6, and thereby satisfied the recommendation level of allowing visual comfort.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.315-320
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• 2022

With the rapid development of urbanization the problems of pedestrian-level wind comfort and natural ventilation of tall buildings are becoming increasingly prominent. The velocity at the pedestrian level ($\overline{MVR}$) and variation of wind pressure coefficients $\overline{{\Delta}C_p}$ between windward and leeward surfaces of tall buildings were investigated systematically through numerical simulations. The examined parameters included building density ρ, height ratio of building α_H, width ratio of building α_B, and wind direction θ. The linear and quadratic regression analyses of $\overline{MVR}$ and $\overline{{\Delta}C_p}$ were conducted. The quadratic regression had better performance in predicting $\overline{MVR}$ and $\overline{{\Delta}C_p}$ than the linear regression. $\overline{MVR}$ and $\overline{{\Delta}C_p}$ were optimized by the NSGA-II algorithm. The LINMAP and TOPSIS decision-making methods demonstrated better capability than the Shannon's entropy approach. The final optimal design parameters of buildings were ρ = 20%, α_H = 4.5, and α_B = 1, and the wind direction was θ = 10°. The proposed method could be used for the optimization of pedestrian-level wind comfort and natural ventilation in a residential area.