Application Of Natural Ventilation Research Articles

Adaptive Comfort Potential in Different Climate Zones of Ecuador Considering Global Warming

Ecuador is a country with several climate zones. However, their behaviour is similar throughout the year, with no peaks of extreme temperatures in the various seasons. This paper is a first approach to study the adaptive comfort behaviour in several areas and populations of the country. Considering the ASHRAE 55-2020 model, energy simulation programmes are applied not just to the current climate scenario but also to the climate change scenarios of 2050 and 2100. The results of locations are analysed and compared to determine their performance. Thanks to their climate characteristics, adaptive comfort models could be applied as a passive strategy, using natural ventilation for building indoor comfort improvement, particularly social dwellings. According to previous studies, some prototypes have not considered the climate determinants in each region. Given the geographic situation of the study areas, the adaptive comfort model could be applied in all cases. Percentages of application of natural ventilation and heating and cooling degree hours have similar behaviours according to the climatic region, with a variation greater than 30% among them.

Passive designs of low-income housing with natural ventilation in tropical region

One of the goals of Sustainable Development goals is sustainable cities and communities. Making cities sustainable means creating career and business opportunities, safe and affordable housing, and building resilient communities and economies. One of the goals of sustainable cities and communities (SDGs 11) is by 2030, ensure access for all to adequate, safe and affordable housing and basic services and upgrade slums. Because the level of housing needs in Jakarta is quite high with limited land available, housing prices soar, this is inversely proportional to the high level of poverty in Jakarta so that many people make illegal and slum settlements to overcome the lack of funds they have. One way to achieve this target is to apply bioclimatic architecture to realize sustainable buildings with affordable operational costs so that the housing built becomes affordable. One way to save energy is to use natural ventilation. This paper presents a study of the application of bioclimatic architecture that can provide good air circulation created using natural ventilation. Natural ventilation is the process of exchanging air inside the building through the help of open building elements. This research is motivated by the current development of cheap apartment architecture in Indonesia which does not support good natural ventilation, people are starting to build something that benefits the market and ignores the importance of good air circulation. Therefore, the promotion and application of natural ventilation as part of low-cost energy consumption and avoiding the sick building syndrome with good air circulation, especially after the corona virus pandemic, is an important issue. The research method used is descriptive quantitative method, in the form of research with a case study and simulation approach. The result achieved is that the building can optimize natural ventilation evenly through orientation, building shape, opening design, etc.

An Appraisal of Indoor Thermal Comfort in a Naturally Ventilated Modified Old Mosque in Banda Aceh, Indonesia

A traditional mosque is a form of conformity between the design and the climate. The warm humid climate in Indonesia characterizes the environment, which is quite challenging to work with. The traditional mosque, with the uniqueness of the roof design, allows the application of a natural ventilation system that can work effectively in circulating air to reduce the effect of heat in the room. However, the application of the design has rarely been found in modern mosques due to the widespread use of the dome. This study appraised Tgk Dianjong Mosque, one of the old mosques in Banda Aceh, Indonesia. The old mosque was modified by replacing the roof material and ventilation. This study aims to appraise the indoor thermal comfort of the mosque considering the application of natural ventilation. The method used in this research is descriptive quantitative, with research data collected through physical measurements, i.e., air temperature, relative humidity, and air velocity. The collected data were analyzed using the CET (Corrected Effective Temperature) index and assessed based on SNI 03-6572-2001. Multiple linear regression analysis was conducted to determine how much wind speed influences the thermal condition of the mosque. The study was conducted for two days, with the selected time being in the morning, afternoon, and evening to obtain more varied data. This study performs that the renovation of replacing the roof ventilation with fixed glass would contribute to the lack of airspeed throughout the mosque. The old material of the roof, i.e., leaf grass, was displaced with a metal roof, creating a highly effective temperature and hence indicated as uncomfortable.

Typical meteorological year data analysis for optimal usage of energy systems at six selected locations in Nigeria

ABSTRACT In this study, the typical meteorological year (TMY) data for six locations representing the six geopolitical zones in Nigeria were generated and analyzed using the Sandia method. The analysis shows that seasonal variations exist in all the selected locations indicating two distinct seasons: the dry and wet seasons with varying lengths from north to south of the country. Due to its high global radiation levels (21–25 MJ/m2/d), the North is a desirable location for solar-thermal systems. In addition, the high monthly mean temperature variations (~18°C), low relative humidity (RHM) (15%) and constant wind speeds (4 m/s) experienced in the first 3 months of the year aid the installation of wind energy systems and the application of evaporative cooling techniques that reduce the thermal load and energy consumption of buildings. On the other side, the high RHM (80%) and mediocre radiation values derived almost throughout the year in the Southwest, Southeast and South–south regions discourages the extensive application of evaporative cooling and solar energy-based systems in such locations, but the moderate wind speeds (2.9 m/s) and monthly mean temperature variations associated with these regions between the first 3 months of the year allow for the application of natural ventilation and some passive cooling systems so as to reduce the thermal load of buildings in the regions. The information presented in this work can serve as a guide for design and selection of energy systems and application of energy-related projects in Nigeria.

The trend of natural ventilation potential in 74 Chinese cities from 2014 to 2019: Impact of air pollution and climate change

Air pollution and unsuitable climatic conditions both limit the application of natural ventilation (NV). The combined effects of climate change and air pollution on NV's potential are unknown, particularly in China, where the atmospheric environment has improved greatly since 2014, but temperatures have increased with global warming. The purpose of this study is to analyze the effects of coupled changes in environmental governance and climate change on the potential for NV in China from 2014 to 2019 and identify critical factors limiting NV use. Four NV scenarios were investigated pertaining to temperature, humidity, wind speed, and six atmospheric pollutants. NV potential decreased when only climatic parameters was considered, but increased when pollutant limitations were considered from 2014 to 2019. The cold region lost the most NV hours (54.9%) while the mild region lost the fewest hours (20.3%). Natural ventilation worked best during summer and worst in winter. Shenzhen, Kunming, Fuzhou, and Haikou showed the highest NV potential in spring, summer, autumn, and winter, respectively. The average proportion of the NV hours lost in the 74 cities was 46.7% due to air pollution in 2019, while the proportion was 71.1% in 2014. The main factors that limited NV hours were PM2.5, PM10, and NO2 pollution. While the air pollution limits on the NV hours were reduced substantially in 2019 when compared with those in 2014, the air pollution levels in China remain high, and further improvements in the air quality are still required, particularly in the cold region.

Smart Folding and Floating Shelter Design for Disaster Mitigation with Natural Ventilation and UVC System

The global COVID-19 outbreak has hit the world in the last two years. Indonesia itself recorded positive cases of COVID-19 of approximately 4 million cases as of September 15, 2021. In addition, the frequency of occurrence of natural disasters in Indonesia, which is relatively high every year, requires our collective attention. In early 2021, there have been several natural disasters, including floods in South Kalimantan, earthquakes in West Sulawesi, and others. If the impact of the natural disaster makes residents must do the evacuation, a proper shelter (evacuee camp) and prioritizes health protocols are needed. Therefore, this study discusses the design innovation of disaster response shelters in the form of smart folding and floating shelters designed for a shelter with a capacity of one family (4-5 people). This capacity limitation is to maintain health protocols and suppress the transmission of the Coronavirus in evacuation areas. Our designed shelter prepared in a compact form to facilitate evacuation mobility and can be implemented in all types of disasters with a folding and floating structure system (the shelter can float and be folded). The material used is light steel as the main structure and cork wall as a material that allows the shelter to float. We designed natural ventilation to regulate air circulation, integrated with an ultraviolet C (UVC) lamp. The UVC lamp is intended as a disinfectant against the Coronavirus. Thus, the application of natural ventilation and disinfection using UVC can provide a cleaner air supply. This air supply and circulation are shown in our simulation results using ANSYS Fluent. These results show that smart folding and floating shelter designs can be used for disaster mitigation.

Performance validation of the heat extraction performance by the natural ventilation with a board-coupled shaft in a deep buried tunnel

Experiments were conducted in a 1/20 scale model tunnel, a higher shaft (5 times the tunnel height) was applied to model the shaft in a deep buried tunnel. Researches have validated that the board-coupled shaft can efficiently eliminate the plug-holing phenomenon and improve the smoke and heat extraction performance when the board-coupled shaft is suitably applied in a shallow buried tunnel. The purpose of this paper is to explore whether the board-coupled shaft (BCS) is effective and has stable heat extraction performance in deep buried tunnels. The influence of heat release rate (HRR) and board location on the heat extraction performance was investigated. The experimental results show that the BCS is effective and has stable heat extraction performance for the deep buried tunnels applied in this study. Also, an analytical solution for predicting the dimensionless smoke layer thickness in the one-dimensional flow region was developed, and it can be found that the dimensionless smoke layer thickness in the one-dimensional flow region depends only on the longitudinal position and doesn’t rely on the HRR. Furthermore, based on the general condition that the first shaft cannot extract the entirety of the smoke, two empirical correlations were derived for predicting the dimensionless temperature difference (ΔTs∗) and the dimensionless heat extraction rate (qs∗) in the BCS under different HRRs and board locations. These studies may contribute positive significance for promoting the application of natural ventilation with vertical shafts in deep buried tunnels.

Effects of Pivot Windows and Wing Walls on Single Sided Natural Ventilation in Rumah Susun (Walk Up Flat)

Rumah susun (walk up flat) are one of the buildings that rely on natural ventilation. However, the application of natural ventilation in rumah susun (walk up flat) in urban areas is influenced by tropical climate problems such as high temperatures and low wind speeds. The design of the openings in the facade has not been able to distribute air into rooms properly. In addition, the layout design makes single-sided natural ventilation the only strategy possible for double loaded corridor type flat. This study aimed to determine the effect of a combination of pivot window designs and wing walls in directing and distribute air into room. The study was conducted in two stages, that was field measurements and experimental with Computational Fluids Dynamics simulations. Simulations were conducted on a combination designs of wing walls and pivot window with 45o and 90o opening angles to determine their effects on the distribution and indoor air velocity. The combination design of wing walls and pivot window created a pressure difference so that it could increase indoor air velocity under both oblique and parallel to the opening. In the direction of the wind that was not oriented to the openings, the combination of wing walls and vertical pivot windows with 90o opening angles increased indoor air velocity up to five times in the corner room. While the 45o opening angle increased the indoor air velocity up to seven times than base case condition in a middle room.

Qualitative study of airflow structure across wooden louvred window panels for natural ventilation applications

Window ventilation usually used in energy-efficient buildings as an effective natural ventilation system to provide an adequate opening for fresh air to flow into the interior space. It could help to reduce the indoor air temperature and limit the contaminants in buildings. This study aimed to visualise the airflow structure across a wooden louvred window panel using the smoke flow visualisation technique at different airflow speeds of 0.5, 1.0, 2.0, 3.0 and 5.0 m/s in a closed-loop wind tunnel. Two Sony 1920 × 1080i cameras captured the airflow structure, which took the side view, rear view, front view and back view images. The wooden louvred window panel promotes optimum outdoor airflow and facilitates continuous air exchange to replace the indoor air. Results showed that smoke filled the space quickly at the highest airflow speed of 5 m/s. This study used an inclination angle of 75° for the wooden louvred window panel to avoid rain splatter. Besides, wood material could be used as a facade shading device. Therefore, installing the wooden louvred window panels could enhance natural ventilation, ensure indoor thermal comfort and reduce indoor air contaminants.

Experimental and theoretical studies on the smoke temperature distribution along the tunnel ceiling with natural ventilation by the board-coupled shafts

Experiments were conducted in a 1/20 scale model tunnel to explore the gas temperature distribution along the tunnel ceiling by the natural ventilation, both the traditional shaft and the board-coupled shaft (BCS) were included. The influence of the shaft type and the board location on the gas temperature distribution along the tunnel ceiling was investigated. The results indicate that the variation trends of excess gas temperature distribution in the near fire region and the far fire region are consistent with the exponential attenuation, whether it is a traditional shaft or a BCS shaft. The relational function of the reference temperature between the far fire region and the near fire region was developed. Beyond that, the correlation function between the smoke layer thickness in the near fire region and the far fire region was developed. Furthermore, the mechanisms of the main heat transfer in the near fire region and the far fire region were discussed. And based on the premise that the radiative heat transfer dominates the heat transfer to the tunnel walls in the near fire region and the convective heat transfer dominates the heat transfer in the far fire region, empirical models for predicting the ceiling excess gas temperature distribution in the near fire region and the far fire region were developed. These studies may contribute positive significance for promoting the application of natural ventilation with vertical shafts.

Experimental studies on the smoke extraction performance by natural ventilation with a board-coupled shaft in a deep buried tunnel

In theory, if the plug-holing phenomenon can be effectively eliminated, the application of natural ventilation with vertical shaft will no longer be limited to shallow buried tunnels, or even extended to deep buried tunnels. Researches have validated that the board-coupled shaft (BCS) can efficiently eliminate the plug-holing phenomenon and promote the smoke extraction performance in a shallow buried tunnel. The purpose of this paper is to explore whether the BCS is effective and has stable smoke extraction performance in deep buried tunnels. Experiments were conducted in a 1/20 scale model tunnel, and the height of the board-coupled shaft applied in this study is 5 times the height of the tunnel height. The influence of heat release rate (HRR) and board location on the smoke extraction performance was investigated. Experimental results indicated that the BCS is effective and has stable smoke extraction performance for the deep buried tunnel applied in this study. Besides, it can be found that the smoke extraction efficiency of the BCS will be improved and the improvement in the smoke extraction performance with BCS is stable when the power of the fire source increases. Also, the optimal board location for the BCS to achieve the peak smoke extraction performance was obtained and the peak smoke extraction performance of the BCS is about 1.451–1.457 times of the traditional shaft. Beyond that, two dimensionless correlations were developed under the general condition that the first shaft cannot extract the entirety of the smoke, one is the correlation function for analyzing the smoke temperature difference and the CO concentration in the shaft; the other is the correlation for predicting the dimensionless volume flow rate under different HRRs and board locations. These studies may contribute positive significance for promoting the application of natural ventilation with vertical shafts.

Evaluation of Natural Ventilation Characteristics on the Sultanate of Ternate Mosque

Thermal comfort is very important in mosque buildings, especially during prayer times in order to increase the comfort and solemn in prayer. The usage of air conditioning for the mosque in Ternate City is not recommended because of the energy resources is limited (rotating blackout) and also to reduce its operational cost every month. Therefore, the application of natural ventilation is essential to improve thermal comfort in the mosque. This study aims to identify the characteristics of the natural ventilation system of Sultan Ternate Mosque by analyzing the orientation of inlet and outlet, ratio and dimension of openings, type and position of ventilation through the literature studies and field observations. The results show that the natural ventilation system of Sultan Ternate Mosque uses clerestory ventilation and cross ventilation systems, therefore the indoor thermal conditions can reach a comfortable level. Ventilation types are semicircular and vertical jalousie on the walls, and roof ventilation of 4-levels. The total area of ventilation holes are 110.24 m2, with the ratio is about 1.04 (inlet): 1.00 (outlet).

Natural ventilation potential for residential buildings in a densely built-up and highly polluted environment. A case study

The application of Natural Ventilation (NV) as a measure to improve comfort conditions in transition and summer periods has been a topic of research on the spotlight for years. However, there is a lack of knowledge about how the combined effect of a dense urban layout with high pollutant concentrations may affect its potential. This paper addresses this gap by running detailed thermal simulations for a typical apartment flat located in the Yuzhong district of Chongqing city (China) using a holistic approach that makes use of: i) wind pressure coefficients on building facades from urban-scale CFD simulations, ii) hourly measured values of PM2.5 concentrations and weather variables and iii) indoor environment measurements for validation purposes. Scenario analysis revealed the average amount of air change rates achievable in a year varies from 8 to 15 ACH according to the windows orientation. These figures drop down to around 2 ACH when taking into account reduced windows opening time when outdoor PM2.5 concentrations are too high. The resulting natural ventilation potential of the case study decreases from 4234 h when outdoor pollution is neglected to 2707 and 529 h when considering the exposure thresholds set by the Chinese government and the WHO respectively.

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Sustainable High-rises

Sustainable High-rises

Sustainable High-rises

Noise-reducing vents for windows in warm, humid, tropical countries

ABSTRACTSustainable building design requires the application of natural ventilation, which has three prerequisites – a comfortable outdoor air temperature (20–25°C), unpolluted outdoor air and a low-noise environment (under 55 dBA). There are many locations where the first two prerequisites are met, but the environmental noise makes applying natural ventilation challenging. This research developed an auxiliary noise-reducing vent for windows (NRVW) that allows daylight and outdoor air to enter the room while reducing the penetration of outdoor noise. As an auxiliary, the NRVW is intended to be integrated into any (double) glazed windows with a sound transmission class (STC) above 25 dBA. The research used physical model experiments to measure the NRVW’s STC and outdoor–indoor transmission class (OITC). Digital model simulation was used to measure the NRVW’s ventilation performance. It was found that NRVW has a rating of STC 18 and OITC 16, and it generates indoor air velocity of 0.015–0.086 m/s in the occupants’ zone for an outdoor wind speed of 1–5 m/s. Modification of the room interior increases the indoor air velocity to 0.147 m/s. Computer simulation also demonstrated that, with an occupant inside the room, an outdoor air temperature of 25°C and outdoor wind speed of 1–5 m/s maintained the indoor air temperature at 25.309–25.258°C, indicating that the resulting airflow could keep the indoor air temperature low. Although the NRVW was originally developed for warm–humid climate conditions, it is also applicable for other climates if the required outdoor conditions are met.

What are the green technologies for sustainable housing development? An empirical study in Ghana

AbstractThe housing industry is a major contributor to global climate change, environmental pollution, and resource depletion. The adoption of green technologies in housing development is a way to realize sustainable development goals. This research aims to identify the green technologies that are important to achieve sustainable housing development, in particular Accra, Ghana. Due to differences in climate, focusing on Accra helps validate the findings of this study. To achieve the objective, 28 green technologies were identified from a comprehensive literature review, and a questionnaire survey was done with 43 professionals with green building experience. The results indicated that application of natural ventilation, application of energy‐efficient lighting systems, optimizing building orientation and configuration, application of energy‐efficient high efficient heating, ventilation, and air‐conditioning system, and installation of water‐efficient appliances and fixtures were the five most important green technologies to achieve sustainable housing development. Furthermore, water efficiency technologies and energy efficiency technologies had the highest level of importance. The identified green technologies form a conceptual framework which can be used to guide the identification and selection of green technologies for sustainable housing development. The research findings would be useful for industry professionals responsible for decision making during the design stage of housing developments. Theoretically, this study adds to the literature by presenting one of the first studies in its kind focusing on green technologies for sustainable housing development within the Ghanaian context.

Sustainable High-rises

Sustainable High-rises

A Study of Local Environment of Harran Historical Domed Houses in Terms of Environmental Sustainability

The aim of this study was to emphasize the close relationship between the local environment of the city of Harran and sustainability. In this study, the domed houses of Harran, a district in the province of Sanliurfa located in the Southeast of Turkey, were studied to investigate the natural ventilation performance, climatic data and insulation properties of the materials used in the houses. In this paper, firstly, the physical environment parameters of the region were described. Then detailed experimental studies were carried out to determine the natural ventilation characteristics of the houses. The experiments conducted in this study were carried out on one of the most preserved houses in the city. The application of natural ventilation designed in contemporary buildings maintaining harmony with nature was discussed and some recommendations on the relationship between buildings and local environment parameters were presented. We strive to find the balance between the environment, and sustainability. Vernacular Harran houses present messages good harmony of nature with human being life in concept of a healthy environment, cleaner production, climatic building design and re-usable building material. The domed houses of Harran in the hot arid climate region are noteworthy examples regarding good design for a sustainable future. Houses? extraordinary architectural features provide environmental comfort inside the houses without the need for energy consumed by air conditioning and other remedies. Harran houses are interesting samples that have reached daily life with the use of recycled materials and the construction-making period that reduces energy consumption. Houses offer solutions that respond to survival needs of inhabits as well as environmental comfort.

The application of natural ventilation of residential architecture in the integrated design

As one of the important parts in the architecture design, ventilation fully reflects one important factor of energy conservation to some extent. To ensure that decreasing use of energy resources to the maximum extent in architectures and make architectures harmonize with their surroundings, which have become important pursuing gradually for residential architecture, at present, integrated design of residential architecture should not only highlight natural ventilation technique, but also should integrate natural ventilation and main feature of local climate, etc. What’s more, designers shall carry out unified analysis on the base of taking all factors into consideration. This point is more important. By this way, architecture technique can be more comprehensive and complete. With the guidance of sustainable development concept, natural ventilation as one of ecological technologies is applied extensively in many architecture designs owing to its economic effect and health benefit.