Effect of natural ventilation mode on thermal comfort and ventilation performance: Full-scale measurement

2017 ◽  
Vol 156 ◽  
pp. 1-16 ◽  
Author(s):  
Sara Omrani ◽  
Veronica Garcia-Hansen ◽  
Bianca R. Capra ◽  
Robin Drogemuller
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Full Scale ◽  
Ventilation Mode ◽  
Ventilation Performance

The Potential of Natural Ventilation in Single-Sided Ventilated Apartment to Improve Indoor Thermal Comfort and Air Quality

2011 ◽  
Author(s):  
M. F. Mohamed ◽  
M. Behnia ◽  
S. King ◽  
D. Prasad
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Architectural Element ◽  
Flat Design ◽  
Effective Ventilation ◽  
Computational Fluid Dynamics Cfd ◽  
Ventilation Performance

Cross ventilation is a more effective ventilation strategy in comparison to single-sided ventilation. In the NSW Residential Flat Design Code1 (RFDC) the majority of apartments are required to adopt cross ventilation. However, in the case of studio and one-bedroom apartments, it is acknowledged that single-sided ventilation may prevail. Deep plan studio and one-bedroom apartments may achieve lower amenity of summer thermal comfort and indoor air quality where mechanical ventilation is not provided by air conditioning. Since compliance with the code may allow up to 40% of apartments in a development in Sydney to be single sided, it is important to understand the natural ventilation performance of such apartments. The objective of this paper is to investigate the natural ventilation potential in single-sided ventilated apartments to improve indoor air quality and thermal comfort. This investigation includes simulating various facade treatments involving multiple opening and balcony configurations. Balcony configurations are included in this study because, in Sydney, a balcony is a compulsory architectural element in any apartment building. The study uses computational fluid dynamics (CFD) software to simulate and predict the ventilation performance of each apartment configuration. This study suggests that properly configured balconies and openings can significantly improve indoor ventilation performance for enhanced indoor air quality and thermal comfort, by optimizing the available prevailing wind. However, it is important to note that inappropriately designed fac¸ade treatments also could diminish natural ventilation performance.

A numerical investigation on the impacts of voids combinations on natural ventilation of high-rise residential building

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hamza Laloui ◽  
Noor Hanita Abdul Majid ◽  
Aliyah Nur Zafirah Sanusi
Keyword(s):  
Thermal Comfort ◽  
Indoor Air ◽  
Design Methodology ◽  
Natural Ventilation ◽  
Residential Building ◽  
Air Velocity ◽  
Content Type ◽  
High Rise ◽  
Living Unit ◽  
Ventilation Performance

Purpose This paper aims to investigate the impacts of introducing voids combinations on natural ventilation performance in high-rise residential building living unit. Design/methodology/approach This study was carried out through field measurement and computational fluid dynamics methods. The parameters of the study are void types and sizes, and a wind angle was used to formulate case studies. Findings The results indicate that the provision of a single-sided horizontal void larger by 50% increase the indoor air velocity performance up to 322.37% to 0.471 m/s in the living unit and achieves the required velocity for thermal comfort. Originality/value Passive design features are the most desirable techniques to enhance natural ventilation performance in the high-rise residential apartments for thermal comfort and indoor air quality purposes.

scholarly journals Ventilation Characteristics and Performance Evaluation of Different Window-Opening Forms in a Typical Office Room

2021 ◽  
Vol 11 (19) ◽  
pp. 8966
Author(s):  
Yuanyuan Wang ◽  
Yanzhe Yu ◽  
Tianzhen Ye ◽  
Quan Bo
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Cfd Simulation ◽  
Thermal Sensation ◽  
Ventilation Rate ◽  
Window Opening ◽  
Ventilation Modes ◽  
Ventilation Performance ◽  
Scale Experiment ◽  
And Performance

As most existing office buildings in China lack fresh air systems for ventilation, natural ventilation with windows remains the main means of improving indoor air quality and adjusting indoor thermal comfort. However, knowledge of the ventilation characteristics of various window-opening forms in actual buildings is limited and current methods for evaluating ventilation performance lack a comprehensive consideration of ventilation rate and thermal comfort. In this study, the ventilation characteristics of different window-opening forms were systematically compared by conducting computational fluid dynamics (CFD) simulations. A full-scale experiment was conducted in a typical office room in a university in Tianjin to validate the CFD simulation. Two ventilation modes (wind-driven cross-ventilation and temperature-driven single-sided ventilation), three window-opening angles, and seven window types were investigated. Additionally, the ratio of the ventilation rate to the absolute value of thermal sensation was used to quantify the indoor natural-ventilation performance. The results showed that a sliding window with a full opening has the highest discharge coefficients of 0.68 and 0.52 under wind-driven cross-ventilation and temperature-driven single-sided ventilation, respectively, and top-hung windows opening both inwards and outwards have better ventilation performance than other window types under the two ventilation modes. This study is applicable to the design and practice of natural ventilation.

EFFECT OF BUILDING PLAN FORM ON HUMAN THERMAL COMFORT IN NATURALLY VENTILATED OPEN-PLAN ENCLOSURES LOCATED IN HOT CLIMATES

2017 ◽  
Vol 12 (2) ◽  
pp. 112-129 ◽  
Author(s):  
Omar S. Asfour
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Weighted Average ◽  
Climatic Conditions ◽  
Air Velocity ◽  
Human Thermal Comfort ◽  
Velocity Magnitude ◽  
Open Plan ◽  
Ventilation Performance ◽  
Common Observation

This study aims to examine the effect of building plan form on internal thermal comfort conditions in naturally ventilated open-plan buildings located in hot climates. The study examined the square and the rectangular plan forms in relation to several values of wind direction, building plan depth, and climatic conditions. The study utilised CFD for ventilation prediction, DesignBuilder for thermal modelling, and the Tropical Summer Index (TSI) for thermal comfort assessment. These three tools were integrated in a quantitative approach to fulfil the study aim. The study concluded that the use of area-weighted average velocity magnitude is more accurate in the assessment of natural ventilation performance, as it accounts for both internal velocity magnitude and distribution. The study confirmed the common observation that the use of shallow building plans is more effective to increase internal air velocity and improve internal thermal comfort. At some point of increased plan depth, the internal air velocity magnitude dramatically decreases. In the three examined wind directions, this occurred when the plan depth exceeded 3H in the square cases and 2.5H in the rectangular ones, where H is the building height. This value is much less than the commonly recommended maximum value of 5H. The study also concluded that reducing building depth in the square cases has generally more potential to improve thermal comfort conditions when compared with the rectangular cases. The gross increase in Percentage of People Comfortable, PPC, in all the examined cases was 23% in the square cases, compared to 11% in the rectangular cases.

scholarly journals The Impact of Air Well Geometry in a Malaysian Single Storey Terraced House

2019 ◽  
Vol 11 (20) ◽  
pp. 5730 ◽  
Author(s):  
Pau Chung Leng ◽  
Mohd Hamdan Ahmad ◽  
Dilshan Remaz Ossen ◽  
Gabriel H.T. Ling ◽  
Samsiah Abdullah ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Natural Ventilation ◽  
Heat Dissipation ◽  
Air Velocity ◽  
Wet Bulb Globe Temperature ◽  
Ventilation Technique ◽  
Ventilation Performance ◽  
Globe Temperature ◽  
The Impact

In Malaysia, terraced housing hardly provides thermal comfort to the occupants. More often than not, mechanical cooling, which is an energy consuming component, contributes to outdoor heat dissipation that leads to an urban heat island effect. Alternatively, encouraging natural ventilation can eliminate heat from the indoor environment. Unfortunately, with static outdoor air conditioning and lack of windows in terraced houses, the conventional ventilation technique does not work well, even for houses with an air well. Hence, this research investigated ways to maximize natural ventilation in terraced housing by exploring the air well configurations. By adopting an existing single storey terraced house with an air well, located in Kuching, Sarawak, the existing indoor environmental conditions and thermal performance were investigated and monitored using scientific equipment, namely HOBO U12 air temperature and air humidity, the HOBO U12 anemometer and the Delta Ohm HD32.3 Wet Bulb Globe Temperature meter. For this parametric study, the DesignBuilder software was utilized. The field study illustrated that there is a need to improve indoor thermal comfort. Thus, the study further proposes improvement strategies to the existing case study house. The proposition was to turn the existing air well into a solar chimney taking into account advantages of constant and available solar radiation for stack ventilation. The results suggest that the enhanced air well was able to improve the indoor room air velocity and reduce air temperature. The enhanced air well with 3.5 m height, 1.0 m air gap width, 2.0 m length was able to induce higher air velocity. During the highest air temperature hour, the indoor air velocity in existing test room increased from 0.02 m/s in the existing condition to 0.29 m/s in the hottest day with 2.06 °C air temperature reduction. The findings revealed that the proposed air well could enhance the thermal and ventilation performance under the Malaysia tropical climate.

URBAN FACADE GEOMETRY ON OUTDOOR COMFORT CONDITIONS: A REVIEW

2020 ◽  
Vol 4 (1) ◽  
pp. 45
Author(s):  
Elahe Mirabi ◽  
Nasrollahi Nazanin
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Natural Ventilation ◽  
Flow Behavior ◽  
Air Flow ◽  
Urban Geometry ◽  
Wide Range ◽  
Low Energy Buildings ◽  
Outdoor Comfort ◽  
Solar Access

<p>Designing urban facades is considered as a major factor influencing issues<br />such as natural ventilation of buildings and urban areas, radiations in the<br />urban canyon for designing low-energy buildings, cooling demand for<br />buildings in urban area, and thermal comfort in urban streets. However, so<br />far, most studies on urban topics have been focused on flat facades<br />without details of urban layouts. Hence, the effect of urban facades with<br />details such as the balcony and corbelling on thermal comfort conditions<br />and air flow behavior are discussed in this literature review. <strong>Aim</strong>: This<br />study was carried out to investigate the effective factors of urban facades,<br />including the effects of building configuration, geometry and urban<br />canyon’s orientation. <strong>Methodology and Results</strong>: According to the results,<br />the air flow behavior is affected by a wide range of factors such as wind<br />conditions, urban geometry and wind direction. Urban façade geometry<br />can change outdoor air flow pattern, thermal comfort and solar access.<br /><strong>Conclusion, significance and impact study</strong>: In particular, the geometry of<br />the facade, such as indentation and protrusion, has a significant effect on<br />the air flow and thermal behavior in urban facades and can enhance<br />outdoor comfort conditions. Also, Alternation in façade geometry can<br />affect pedestrians' comfort and buildings energy demands.</p>

scholarly journals Experimental Data and Simulations of Performance and Thermal Comfort in a Typical Mediterranean House

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Thermal Characterization ◽  
Energy Performance ◽  
Building Stock ◽  
Energy Demands ◽  
Dwelling House ◽  
Account Standard

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.

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