scholarly journals Natural ventilation for office building retrofit in dense urban context under hot and humid climate

2021 ◽  
Vol 21 (2) ◽  
pp. 67-87
Author(s):  
Marilia Ramalho Fontenelle ◽  
Leopoldo Eurico Gonçalves Bastos ◽  
Sylvie Lorente
Keyword(s):  
Thermal Comfort ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Air Flow ◽  
Office Building ◽  
Temperate Climate ◽  
Humid Climate ◽  
Adaptive Comfort ◽  
Hot And Humid Climate ◽  
Indoor Air Flow

Abstract Recent studies underline that simple and non-invasive retrofit solutions can recover natural ventilation potential in existing buildings under temperate climate. Nonetheless, the efficiency of these solutions in dense urban contexts under hot and humid climate remains unclear. This paper aims to evaluate the thermal comfort gains caused by natural ventilation when retrofitting an office building in downtown Rio de Janeiro. Computational Fluid Dynamics (CFD) and thermal simulations are carried out on Ansys CFX and Design builder to assess indoor air flow before and after retrofit. The diagnosis of the current scenario indicates that the surrounding buildings block a significant part of the wind flow, and occupants experience only a few hours of thermal comfort during the year, especially on lower floors. To increase indoor air flow, the fixed upper windows were transformed into pivot windows and kept open permanently. This measure increases the annual hours of thermal comfort by 0.5-35%, depending on the floor and the adaptive comfort model. These findings suggest that natural ventilation itself may not be sufficient to ensure occupants' comfort throughout the year under the investigated context.

Improving indoor air quality and thermal comfort by total heat exchanger for an office building in hot and humid climate

2014 ◽  
Vol 20 (7) ◽  
pp. 731-737 ◽  
Author(s):  
Fu-Jen Wang ◽  
Meng-Chieh Lee ◽  
Tong-Bou Chang ◽  
Yong-Sheng Chen ◽  
Ron-Chin Jung
Keyword(s):  
Heat Exchanger ◽  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Total Heat ◽  
Office Building ◽  
Humid Climate ◽  
Hot And Humid Climate

Natural Ventilation of a Solar House in Hot and Humid Climate: A Study Using Building Energy Simulation Method

2014 ◽  
Author(s):  
Elise Belleil ◽  
Long Phan ◽  
Cheng-Xian Lin ◽  
Mirko Schäfer ◽  
Johannes Wagner
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Cooling System ◽  
Ventilation System ◽  
Humid Climate ◽  
Human Thermal Comfort ◽  
Reduce Energy Consumption ◽  
Hot And Humid Climate ◽  
Solar House

The solar powered house at the Engineering Center of Florida International University is out of the U.S. Solar Decathlon 2005 competition. A computational simulation using EnergyPlus is conducted to study different ventilation strategies in this solar house model, with consideration of the hot and humid climate in Miami, Florida. Several modes of ventilation including mechanical cooling systems, natural ventilation utilization, and hybrid systems were considered to seek the best possible option for ventilation in such extreme climate. While the need for a mechanical ventilation system is always present, a resort to natural ventilation could significantly reduce energy consumption. As for natural ventilation utilization, a few methods including earth tubes (ET), thermal chimneys (TC), cooling towers (CT), and openings have been simulated and compared with the mechanical cooling system of the original house. However, as the simulation results suggested, relying on only natural ventilation could cause a dramatic impact to the human thermal comfort. Therefore, a coupling strategy between mechanical systems and natural ventilation was extensively investigated in hope for a better solution in terms of both energy consumption and thermal comfort. In fact, the hybrid system has proved to tremendously reduce energy consumption while complying with the minimum requirements for thermal comfort recommended by ASHRAE standards.

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>

Indoor air flow analysis based on lattice Boltzmann methods

2002 ◽  
Vol 34 (9) ◽  
pp. 941-949 ◽  
Author(s):  
B Crouse ◽  
M Krafczyk ◽  
S Kühner ◽  
E Rank ◽  
C van Treeck
Keyword(s):  
Indoor Air ◽  
Lattice Boltzmann ◽  
Air Flow ◽  
Flow Analysis ◽  
Lattice Boltzmann Methods ◽  
Indoor Air Flow

scholarly journals Indoor Air Quality (IAQ): Accuracy of Natural Ventilation for Temperature, Air Flow Rate and Relative Humidity (RH) in School Building Classrooms

2018 ◽  
Vol 7 (3.9) ◽  
pp. 42
Author(s):  
Norsafiah Norazman ◽  
Adi Irfan Che Ani ◽  
Nor Haslina Ja’afar ◽  
Muhamad Azry Khoiry
Keyword(s):  
Air Quality ◽  
Relative Humidity ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Air Flow ◽  
Weather Conditions ◽  
Potential Health ◽  
The Hours ◽  
Hot Weather

Indoor Air Quality (IAQ) is an essential matter in achieving students’ satisfaction for the learning process. Building’s orientation is a factor that may encourage sufficient natural ventilation for the classroom occupants. Inadequate ventilation is an issue for most existing classrooms. The purpose of this paper is to analyze the accuracy of natural ventilation in classrooms. Therefore, experimental on 20 classrooms has been conducted by using Multipurpose Meter at secondary school buildings in Malaysia. The findings indicated that the accuracy of natural ventilation testing was below the permissible limits throughout the hours monitored, thus this may cause potential health hazards to the students. Temperature and air flow rates were lower than 23 °C and 0.15 m/s respectively, it fulfilled the basic requirements as a standard learning environment. However, measurements taken showed the overall relative humidity (RH) in the classrooms can be categorized as acceptable with 40% to 70% range. On the basis of these findings, it is evident that naturally ventilated classrooms are important especially due to energy efficiency, whereas mechanical ventilation should only be installed as an alternative under extremely hot weather conditions.   

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.

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