scholarly journals Optimization Of Natural Ventilation In Building As Passive Design Strategy For Health Security

2020 ◽  
Vol 1 (1) ◽  
pp. 25-31
Author(s):  
Cynthia Permata Dewi
Keyword(s):  
Natural Ventilation ◽  
Ventilation System ◽  
Electrical Energy ◽  
Living Room ◽  
Ventilation Strategy ◽  
Minimum Level ◽  
Air Velocity ◽  
Health Security ◽  
Sliding Windows ◽  
Air Movement

The use of natural ventilation strategy in a building is currently encouraged by the emergence of a pandemic Covid-19. In addition to its advantages in minimizing the use of electrical energy, the natural ventilation system is believed could reduce the possibility of spreading the virus. One design approach to this system is by using the window's design properly. Air movement inside a building should be utilized well to allow the movement from inlet to outlet. The position of the window was one of the variables examined in this study besides the types of the window. This study found that the use of a combination of 300 awnings produced the highest airspeed in the living room (R1), while a combination of horizontal sliding windows resulted in the highest air velocity in the bedroom (R2). Still, the airspeed generated from the two combinations less than the minimum level of it is generally required, 0.75 – 0.9 m/s.

scholarly journals Influence of Wind on Air Movement in a Free-Stall Barn During the Summer Period / Wpływ wiatru na ruch powietrza w oborze wolnostanowiskowej w okresie letnim

2013 ◽  
Vol 13 (1) ◽  
pp. 109-119 ◽  
Author(s):  
Piotr Herbut ◽  
Sabina Angrecka ◽  
Grzegorz Nawalany
Keyword(s):  
Natural Ventilation ◽  
Air Flow ◽  
Ventilation System ◽  
Air Velocity ◽  
Summer Period ◽  
Air Masses ◽  
Air Movement ◽  
Microclimatic Conditions ◽  
Hot Weather ◽  
Different Levels

Abstract Use of natural ventilation in the barn should lead to optimal microclimatic conditions over the entire space. In the summer, especially during hot weather, higher air velocity cools cows, which helps to avoid heat stress. The paper presents the results of studies on the evolution of air movement in a modernized free-stall barn of the Fermbet type with the natural ventilation system during the summer period. Based on measurements of velocity and direction of air flow (inside and outside the barn) and observations of smoke indicator, the movement of air masses in different parts of the barn was identified. Significant variations of air flow at different levels of the barn were found. These differences deviate from the accepted patterns of natural ventilation, which can be found in the literature. The range of a draught and stagnant air along with the conditions in which they are built was determined. On this basis, recommendations regarding the location of barns on the plots and the improvement of ventilation in summer were made.

scholarly journals Optimizing air velocity for the underfloor forced ventilation to protect a refrigerated warehouse from frost heaving

2018 ◽  
Vol 38 (3) ◽  
pp. 321-327
Author(s):  
Jingfu Jia ◽  
Manjin Hao ◽  
Jianhua Zhao
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Frost Heave ◽  
Forced Ventilation ◽  
Air Velocity ◽  
Set Up

Forced or natural ventilation is the most common measure of frost heave protection for refrigerated warehouse floor. To optimize air velocity for the underfloor forced ventilation system of refrigerated warehouse, a steady state three-dimensional mathematical model of heat transfer is set up in this paper. The temperature fields of this system are simulated and calculated by CFD software PHOENICS under different air velocity, 1.5m/s, 2.5m/s or 3.5m/s. The results show that the optimized air velocity is 1.5m/s when the tube spacing is 1.5m.

scholarly journals Numerical simulations for the optimisation of ventilation system designed for wine cellars

2019 ◽  
Vol 50 (4) ◽  
pp. 180-190 ◽  
Author(s):  
Enrica Santolini ◽  
Alberto Barbaresi ◽  
Daniele Torreggiani ◽  
Patrizia Tassinari
Keyword(s):  
Natural Ventilation ◽  
Ventilation System ◽  
Climatic Conditions ◽  
Mold Growth ◽  
Critical Factors ◽  
Air Velocity ◽  
Wine Production ◽  
First Case ◽  
Dynamics Modelling ◽  
Optimal Configurations

The wine-ageing process is one of the most important phases of the wine production and it can be considerably affected by the micro-climatic conditions inside the ageing rooms. Underground wine cellars in small-medium wineries are designed with natural ventilation systems, able to maintain optimal indoor condition. However, critical factors emerge, such as mold growth or wine evapo-transpiration, where ventilation proved to be poorly designed, insufficient in the first case or excessive in the second one. The zones around the wooden barrels proved to be the most sensitive and problematic. These areas are the most investigated in terms of temperature and humidity values but surprisingly not in terms of air velocity. In this paper, a ventilation system has been designed and optimised to support the lack of ventilation, by means of computational fluid dynamics modelling. Eight configurations have been performed and analysed, identifying the best two according to the air velocity range. Specific parameters have been defined to appreciate the application limits of each configuration. These parameters can be used as reference for system design in similar studies and applications and can help scholars and professionals to identify the optimal configurations for the implementation and proper placement of the system inside a cellar.

scholarly journals The Determination of Indoor Air Quality and Thermal Comfort with Different Space and Ventilation in the Teracce and Bungalow Houses

2021 ◽  
Vol 16 (3) ◽  
pp. 774-793
Author(s):  
Nur Baitul Izati Rasli ◽  
Nor Azam Ramli ◽  
Mohd Rodzi Ismail
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Physical Parameters ◽  
Air Contaminants ◽  
Code Of Practice ◽  
Air Movement

This study observed the influence of different ventilation, indoor and outdoor activities (i.e., cooking, praying, sweeping, gathering, and exhaust from motorcycle) between a bungalow house (i.e., stack and cross ventilation applications) and a terrace house (i.e., one-sided ventilation application). We appraised the indoor air quality (IAQ) and thermal comfort. We monitored the indoor air contaminants (i.e., TVOC, CO, CH2O, PM10, O3, and CO2) and specific physical parameters (i.e., T, RH, and AS) for four days in the morning (i.e., 6.00 a.m. – 9.00 a.m.), morning-evening (i.e., 11.00 a.m. – 2.00 p.m.), and evening-night (i.e., 5.00 p.m. – 8.00 p.m.) sessions. The results found that cooking activities are the major activities that contributed to the increase of the TVOC, CO, PM10, O3, and CO2 concentrations in the bungalow and terrace houses. However, IAQ exceeded the Industry Code of Practice on IAQ (ICOP) limit in the terrace house. The bungalow house applies stack and cross ventilation, double area, and a long pathway of indoor air contaminants movements. Besides that, the results indicated that cooking activities worsen the ventilation system because CO2 exceeded the ICOP limit on Day 2 at 74.1 % (evening-night session) and Day 3 at 13.2 % (morning session), 11% (morning-evening session), and 50.1 % (evening-night session). Moreover, the combination of mechanical (i.e., opened all fans) and natural ventilation (i.e., opened all doors, windows, and fans) is the best application in the house without a cooking ventilator with lower indoor air movement. Furthermore, the temperatures exceeding the ICOP limit of 23-26 °C for both bungalow and terrace houses could be lower indoor air movement, which is less than the ICOP limit of 0.15-0.5 m/s and high outdoor air temperature. Therefore, it is prudent to have an efficient ventilation system for acceptable indoor air quality and thermal comfort in the family house.

scholarly journals Investigation of the Energy Saving Efficiency of a Natural Ventilation Strategy in a Multistory School Building

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1746 ◽  
Author(s):  
Beungyong Park ◽  
Sihwan Lee
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Natural Ventilation ◽  
Cfd Simulation ◽  
Ventilation System ◽  
Internal Heat ◽  
High Energy ◽  
Ventilation Strategy ◽  
Opening And Closing ◽  
Ventilation Rates

Under-ventilation and high energy consumption are some of the problems associated with school classrooms. Thus, it is necessary to develop a ventilation strategy that is characterized by high energy-saving and ventilation efficiency. To this end, this study aims to investigate natural ventilation as a possible strategy to improve the indoor environment while reducing ventilation loads and maintaining energy costs during intermediate seasons. Ventilation and cooling load reductions based on the opening and closing of several windows were analyzed. Window flow coefficients and ventilation rates were measured and used for computational fluid dynamics (CFD) simulation to obtain pressure coefficients for 16 wind directions. The results obtained showed that the improved natural ventilation strategy could be used to effectively establish required indoor conditions (26 °C, 60% RH). Additionally, compared with the mechanical ventilation system with variable refrigerant flow, this natural strategy resulted in a decrease in energy consumption of approximately 30%. However, its application requires that internal heat gain and CO2 emissions, which depend on human population density, as well as the room usage schedule should be considered.

scholarly journals Spatial and Temporal Distribution of Temperature, Relative Humidity and Air Velocity in a Parallel Milking Parlour During Summer Period

2015 ◽  
Vol 15 (2) ◽  
pp. 517-526 ◽  
Author(s):  
Piotr Herbut ◽  
Sabina Angrecka ◽  
Grzegorz Nawalany ◽  
Krzysztof Adamczyk
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Ventilation System ◽  
Temporal Distribution ◽  
Operating Conditions ◽  
Air Velocity ◽  
Summer Period ◽  
Air Movement ◽  
Air Stream ◽  
Relative Air Humidity

Abstract The research aimed at determining the most significant parameters affecting the microclimate of milking parlours, such as temperature, relative humidity and air movement in a parallel milking parlour in real operating conditions. The research was conducted in the summer period, when the risk of heat stress in cattle is higher. To check welfare of cows during milking, days with air temperature >25°C and days with temperature equal or lower than 25°C were analysed. Observation and analysis were performed for air flow in milking parlour, range of supplied air stream and how air movement affects cattle. It was observed that the irregular distribution of air movement led to the development of diverse air velocity in different zones of the milking parlour (0.2-9.0 m∙s-1). As a consequence, the conditions inside the barn were not homogenous for all the cattle. A significant effect of the cows and external air temperature (which depends indirectly on orientation of the milking parlour relative to cardinal directions) on temperature increase (approx 6°C) was concluded, with relative air humidity at the level of 85-90%, during the milking, which led to systematic decrease of microclimatic comfort for cattle. Based on the conducted research, it was concluded that the design of ventilation systems in parallel milking parlours should be preceded by increased research not only on ventilation system efficiency but also on the distribution of flow ventilated air.

The effect of opening windows on the airflow distribution inside naturally ventilated residential bedrooms with ceiling fans

2021 ◽  
pp. 014362442110240
Author(s):  
Thaliyara Kesavan Jayasree ◽  
Basheer Sheeba Jinshah ◽  
Tadepalli Srinivas
Keyword(s):  
Uniform Distribution ◽  
Natural Ventilation ◽  
Air Velocity ◽  
Ansys Fluent ◽  
Room Size ◽  
Air Movement ◽  
Airflow Distribution ◽  
Window Opening ◽  
Ventilation Strategies ◽  
Furniture Layout

Ceiling fans are the most common equipment in any household with electricity to induce a higher air movement since the potential of natural ventilation is limited. However, the higher airflow region is generally limited to the zone below the fan. The non-uniform distribution of airflow is also affected by the furniture layout and airflow from window openings. This study attempts to evaluate the effect of the different window-opening patterns on the airflow inside naturally ventilated bedrooms, having a ceiling fan for air movement with numerical simulations and on-site measurements. The airflow pattern created by a ceiling fan in a room with furniture is modelled and simulated with ANSYS Fluent 2019 R3. The results were validated with on-site measurements and compared with the literature. The air velocity was measured in bedrooms of three different sizes. It was observed that the opening of windows created a better distribution of air irrespective of room size. The non-uniformity of the air velocity is reduced from 76% to 39% with the opening of windows in the larger-sized room. The reduction in non-uniformity is influenced by the location of windows also. The practice of opening windows along with the induced air movement by ceiling fans results in a better distribution of air in the space. Practical application: People tend to depend mainly on ceiling fans even if windows are open in naturally ventilated rooms. A study of patterns of non-uniform distribution of airflow can help designers to improve comfort conditions by specifying the number and location of fans and windows while designing room furniture layout. This aids the building services engineers to provide thermal comfort without always depending on alternative active ventilation strategies.

scholarly journals The Effect Of Outside Corridor’s Orientation to Interior Thermal Condition at Lawang Sewu Semarang.

2018 ◽  
Vol 73 ◽  
pp. 01011
Author(s):  
Benediktus Yosef Arya Wastunimpuna ◽  
Wahyu Setia Budi ◽  
Erni Setyowati
Keyword(s):  
Heat Stress ◽  
Relative Humidity ◽  
Thermal Condition ◽  
Natural Ventilation ◽  
Thermal Conditions ◽  
Standard Theory ◽  
Hot Wire ◽  
Air Movement ◽  
Dutch Colonial

The outside corridor of Dutch Colonial Building in Indonesia was made to make the temperature of the room more comfortable. Lawang Sewu Building in Semarang is one example of a building that has an outside corridor along the building and until now still use natural ventilation. This study focuses on finding out whether there is a difference on the thermal conditions of each room’s orientation, so after that we know the effect of orientation of the outdoor corridor to the temperature of the interior. In this study the experiment based on measurement using Heat Stress WBGT Meter for Wet Bulb Temperature, Dry Bulb Temperature, Relative Humidity, and KW0600653 Hot Wire Anemometer for the air movement. The data will be analysed using thermal standard theory to find out which point has the most comfortable thermal conditions.. At the end of this study will be found the effect of corridor’s orientation to thermal condition of the interior in Lawang Sewu Semarang.

scholarly journals Indoor Climate Performance in a Renovated School Building

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2827
Author(s):  
Pavla Mocová ◽  
Jitka Mohelníková
Keyword(s):  
Indoor Environment ◽  
Natural Ventilation ◽  
Carbon Dioxide Concentration ◽  
Heating System ◽  
Climatic Conditions ◽  
School Building ◽  
Ventilation Strategy ◽  
Indoor Climate ◽  
Microbiological Testing ◽  
Indoor Comfort

Indoor climate comfort is important for school buildings. Nowadays, this is a topical problem, especially in renovated buildings. Poorly ventilated school classrooms create improper conditions for classrooms. A post-occupancy study was performed in a school building in temperate climatic conditions. The evaluation was based on the results of long-term monitoring of the natural ventilation strategy and measurements of the carbon dioxide concentration in the school classroom’s indoor environment. The monitoring was carried out in an old school building that was constructed in the 1970s and compared to testing carried out in the same school classroom after the building was renovated in 2016. Surprisingly, the renovated classroom had a significantly higher concentration of CO2. It was found that this was due to the regulation of the heating system and the new airtight windows. The occupants of the renovated classroom have a maintained thermal comfort, but natural ventilation is rather neglected. A controlled ventilation strategy and installation of heat recovery units are recommended to solve these problems with the classroom’s indoor environment. Microbiological testing of the surfaces in school classrooms also shows the importance of fresh air and solar radiation access for indoor comfort.

Ventilation strategy for random pollutant releasing from rubber vulcanization process

2016 ◽  
Vol 26 (2) ◽  
pp. 248-255 ◽  
Author(s):  
Changsheng Cao ◽  
Jun Gao ◽  
Yumei Hou ◽  
Jie Chen
Keyword(s):  
Production Process ◽  
Ventilation System ◽  
Primary Source ◽  
Emission Characteristic ◽  
Ventilation Strategy ◽  
Exhaust Hood ◽  
Cumulative Emission ◽  
Measurement Results ◽  
Vulcanization Process ◽  
Source Emission

This paper investigates the emission characteristic of a rubber vulcanization process in a workshop and tries to formulate a ventilation strategy for the rubber vulcanization production process with a lower exhaust rate. Measurements were performed to derive detailed source emission characteristic of rubber vulcanization process in a rubber workshop. The measurement results show that the primary source emission process was concentrated within 600 s of a vulcanization process, the corresponding cumulative emission percentage reached up to 95%. Based on random pollutant releasing from rubber vulcanization process, a single local exhaust hood was applied for a curing machine, the corresponding exhaust rate of 4000 m3/h was proven to be reliable for capturing rubber fume by the experimental and numerical methods. The corresponding cumulative capture efficiency of the single local exhaust hood was 92.1% at 600 s. A new ventilation system equipped with single local exhaust hood was further designed for the rubber vulcanization production process line, and the total exhaust rate of this system was only a quarter of the original one used in a large exhaust hood system. These findings have illustrated that the new ventilation system equipped with single local exhaust hood could largely reduce the exhaust rate in a rubber vulcanization workshop.

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