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 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 ANALYSIS OF AIR FLOW DISTRIBUTION IN RESIDENTIAL ROOMS WITH SUPPLY WINDOW VALVES BY MATHEMATICAL MODELING IN ANSYS FLUENT

2019 ◽  
Vol 4 (10) ◽  
pp. 67-73
Author(s):  
О. Симбирев ◽  
O. Simbirev
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Natural Ventilation ◽  
Residential Buildings ◽  
Ventilation System ◽  
Flow Distribution ◽  
Ansys Fluent ◽  
Airflow Distribution ◽  
Standard Values ◽  
Technical Solutions

The main problem highlighted in the article is the deviation of the microclimate parameters from the standard values due to the improper organization of airflow in the residential rooms of apartment buildings. The objective is to obtain a working mathematical model of the natural ventilation system, its study for optimization or modernization. The analysis of the normative literature, scientific works of domestic and foreign scientists, developments in the field of natural ventilation and ventilation of residential buildings is carried out. A mathematical model of air exchange of a residential room with convection is presented and analyzed. The flow rate and air temperature, the temperature on the surface of the heater are set as boundary conditions when creating a mathematical model. The features and regularities of airflow distribution in the room obtained as a result of mathematical modeling are revealed. The distributions of air velocity in the room are given. Difficulties of the organization of effective natural inflow of air and the problems with design of valves of infiltration are designated. Technical solutions aimed at improving the quality of indoor microclimate and energy saving are proposed.

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.

The Impact of Gymnasium Form’s Tilting Side Interfaces on Natural Ventilation and Thermal Comfort of Exercise Site

2014 ◽  
Vol 587-589 ◽  
pp. 490-497
Author(s):  
Jin Li ◽  
Yuan You
Keyword(s):  
Thermal Comfort ◽  
Wind Velocity ◽  
Natural Ventilation ◽  
Change Rate ◽  
Symmetrical Mode ◽  
Air Change Rate ◽  
Window Opening ◽  
Symmetrical Model ◽  
Ventilation Strategies ◽  
The Impact

To improve air change rate and exercise site’s thermal comfort of gymnasium under natural ventilation in hot and humid areas, taking Guangzhou as an example, symmetrical model, unsymmetrical model, and unsymmetrical model with corbel table were simulated and calculated with Fluent and other software. The result indicates that, compared with symmetrical mode, unsymmetrical model and unsymmetrical model with corbel table can improve exercise site’s wind velocity and integral air change rate, and the latter model improves more. Based on unsymmetrical model with corbel table, window-opening ventilation strategies for competition are further put forward. In the end, it discusses about the influence towards thermal comfort of exercise site by natural ventilation in different form models and different use modes.

Simulation of Room Airflow Using Comsol Multiphysics Software

2013 ◽  
Vol 465-466 ◽  
pp. 571-577
Author(s):  
Ade Asmi ◽  
Jouvan Chandra Pratama Putra ◽  
Ismail Abdul Rahman
Keyword(s):  
Mechanical Ventilation ◽  
Mechanical System ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Random Point ◽  
Comsol Multiphysics ◽  
Air Velocity ◽  
Air Conditioning System ◽  
Simulation Process ◽  
Airflow Distribution

Airflow in a room can be supplied both through natural mean and also by the helps of mechanical ventilation. Natural ventilation is more sustainable compared to mechanical system; however natural ventilation, it may not be sufficient to fulfil the need of ventilation for a specific room. This study presents simulation works carried out regarding to the airflow movement in a room due to mechanical ventilation. The measurement of air velocity was taken using Davis anemometer at random point in the room. The measured air velocity then used as an input in simulation work which used Comsol Multiphysics software. The simulation process begins by building up geometry of the room, assigning constant parameters, meshing the geometry of the room, and finally run the solver analysis. The results from simulations indicate that the air distributions in the room are below ASHRAE standard. This is due to the airflow distribution from the airflow injection of air-conditioning system is not well distributed. The simulations results are validated with the measured value and found that the percentage differences between the simulated and measured values are within the range of 3 - 10 %. Keywords: Simulation, Airflow movement, Mechanical ventilation, Comsol Multiphysics software

scholarly journals Development of a CFD Model to Simulate Natural Ventilation in a Semi-Open Free-Stall Barn for Dairy Cows

Buildings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 183
Author(s):  
Nicoletta Tomasello ◽  
Francesca Valenti ◽  
Giovanni Cascone ◽  
Simona M. C. Porto
Keyword(s):  
Dairy Cows ◽  
Natural Ventilation ◽  
Cooling System ◽  
Simulated Data ◽  
Building Design ◽  
Cfd Model ◽  
Air Velocity ◽  
Cfd Modelling ◽  
Climate Conditions ◽  
Airflow Distribution

Natural ventilation is the most common passive cooling system in livestock buildings. The aim of this research is to assess airflow distribution inside a free-stall barn for dairy cows by computational fluid dynamics (CFD) modelling and simulation. The model is validated by using the average values of experimental data acquired in a free-stall barn, which is considered relevant because it is located in a region characterised by hot climate conditions during the summer that could induce animal heat stress. Simulations are carried out in steady-state conditions, and simulated data are validated by the average values of air velocity measurements. Since the modelled air velocity distribution in the barn fits the real one well, the CFD model is considered reliable to simulate other conditions. The application of the proposed CFD model in the simulation of specific building design alternatives could be aimed at studying the related airflow distribution in order to find the best configuration.

ASSESSMENT OF AIR CHANGE EFFECTIVENESS AND THERMAL COMFORT IN A NATURALLY VENTILATED KITCHEN WITH INSECT-PROOF SCREEN USING CFD

2021 ◽  
Vol 16 (3) ◽  
pp. 37-56
Author(s):  
T K Jayasree ◽  
B S Jinshah ◽  
V Lakshmi Visakha ◽  
Tadepalli Srinivas
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
The Other ◽  
Air Velocity ◽  
Ansys Fluent ◽  
Thermal Discomfort ◽  
Ventilation Efficiency ◽  
Warm Sensation ◽  
The Mean ◽  
Real Scenario

ABSTRACT Many dwellings in warm-humid climates attain a comfortable environment by natural ventilation. The opening of exterior windows for ventilation allows the entry of insects along with the breeze. As a remedy, occupants install insect-proof screens on windows resulting in reduced airflow into the interior. This study attempts to evaluate the air change effectiveness and thermal comfort in a residential kitchen with insect-proof screens. A kitchen with insect-proof screens on the windows is compared with a case without insect-proof screens. Numerical simulation was conducted using ANSYS Fluent 2019 R2. The insect-proof screen is modelled as a porous media. The air velocity and temperature measurements were validated by measurements in a real scenario. The presence of insect-proof screens reduced the air velocity inside the space by 82%. However, the airflow pattern in the case with screens was more uniformly distributed. The mean age of the air was considerably higher in the case with insect-proof screens, which in turn resulted in a reduced ACE. The presence of an insect-proof screen resulted in a Predicted Mean Vote (PMV) of 2.79 indicating a ‘hot’ sensation, whereas in the other case, the comfort vote is only 1.93 indicating a ‘warm’ sensation. The presence of insect-proof screens on windows reduced the air velocity and ventilation efficiency, contributing to increased thermal discomfort in the kitchen.

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.

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