Investigation of the natural ventilation of wind catchers with different geometries in arid region houses

2020 ◽  
Vol 14 (3) ◽  
pp. 7109-7124
Author(s):  
Nasreddine Sakhri ◽  
Younes Menni ◽  
Houari Ameur ◽  
Ali J. Chamkha ◽  
Noureddine Kaid ◽  
...  
Keyword(s):  
Arid Region ◽  
Natural Ventilation ◽  
Reduction Rate ◽  
Internal Flow ◽  
Climatic Conditions ◽  
Maximum Pressure ◽  
Ventilation Technique ◽  
Window Position ◽  
The One ◽  
Flow Velocities

The wind catcher or wind tower is a natural ventilation technique that has been employed in the Middle East region and still until nowadays. The present paper aims to study the effect of the one-sided position of a wind catcher device against the ventilated space or building geometry and its natural ventilation performance. Four models based on the traditional design of a one-sided wind catcher are studied and compared. The study is achieved under the climatic conditions of the South-west of Algeria (arid region). The obtained results showed that the front and Takhtabush’s models were able to create the maximum pressure difference (ΔP) between the windward and leeward of the tower-house system. Internal airflow velocities increased with the increase of wind speed in all studied models. For example, at Vwind = 2 m/s, the internal flow velocities were 1.7, 1.8, 1.3, and 2.5 m/s for model 1, 2, 3, and 4, respectively. However, at Vwind = 6 m/s, the internal flow velocities were 5.6, 5.5, 2.5, and 7 m/s for model 1, 2, 3, and 4, respectively. The higher internal airflow velocities are given by Takhtabush, traditional, front and middle tower models, respectively, with a reduction rate between the tower outlet and occupied space by 72, 42, 36, and 33% for the middle tower, Takhtabush, traditional tower, and the front model tower, respectively. This reduction is due to the due to internal flow resistance. The third part of the study investigates the effect of window (exist opening) position on the opposite wall. The upper, middle and lower window positions are studied and compared. The air stagnation or recirculation zone inside the ventilated space reduced from 55% with the lower window to 46% for the middle window and reached 35% for the upper window position. The Front and Takhtabush models for the one-sided wind catcher with an upper window position are highly recommended for the wind-driven natural ventilation in residential houses that are located in arid regions.

scholarly journals Effect of Temperature on Sowing Dates of Wheat under Arid and Semi-Arid Climatic Regions and Impact Quantification of Climate Change through Mechanistic Modeling with Evidence from Field

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 927
Author(s):  
Jamshad Hussain ◽  
Tasneem Khaliq ◽  
Muhammad Habib ur Rahman ◽  
Asmat Ullah ◽  
Ishfaq Ahmed ◽  
...  
Keyword(s):  
Climate Change ◽  
Grain Yield ◽  
Arid Region ◽  
Field Experiments ◽  
Climatic Conditions ◽  
Seasonal Temperature ◽  
Sowing Dates ◽  
Rcp 8.5 ◽  
Semi Arid Region ◽  
Semi Arid

Rising temperature from climate change is the most threatening factor worldwide for crop production. Sustainable wheat production is a challenge due to climate change and variability, which is ultimately a serious threat to food security in Pakistan. A series of field experiments were conducted during seasons 2013–2014 and 2014–2015 in the semi-arid (Faisalabad) and arid (Layyah) regions of Punjab-Pakistan. Three spring wheat genotypes were evaluated under eleven sowing dates from 16 October to 16 March, with an interval of 14–16 days in the two regions. Data for the model calibration and evaluation were collected from field experiments following the standard procedures and protocols. The grain yield under future climate scenarios was simulated by using a well-calibrated CERES-wheat model included in DSSAT v4.7. Future (2051–2100) and baseline (1980–2015) climatic data were simulated using 29 global circulation models (GCMs) under representative concentration pathway (RCP) 8.5. These GCMs were distributed among five quadrants of climatic conditions (Hot/Wet, Hot/Dry, Cool/Dry, Cool/Wet, and Middle) by a stretched distribution approach based on temperature and rainfall change. A maximum of ten GCMs predicted the chances of Middle climatic conditions during the second half of the century (2051–2100). The average temperature during the wheat season in a semi-arid region and arid region would increase by 3.52 °C and 3.84 °C, respectively, under Middle climatic conditions using the RCP 8.5 scenario during the second half-century. The simulated grain yield was reduced by 23.5% in the semi-arid region and 35.45% in the arid region under Middle climatic conditions (scenario). Mean seasonal temperature (MST) of sowing dates ranged from 16 to 27.3 °C, while the mean temperature from the heading to maturity (MTHM) stage was varying between 12.9 to 30.4 °C. Coefficients of determination (R2) between wheat morphology parameters and temperature were highly significant, with a range of 0.84–0.96. Impacts of temperature on wheat sown on 15 March were found to be as severe as to exterminate the crop before heading. The spikes and spikelets were not formed under a mean seasonal temperature higher than 25.5 °C. In a nutshell, elevated temperature (3–4 °C) till the end-century can reduce grain yield by about 30% in semi-arid and arid regions of Pakistan. These findings are crucial for growers and especially for policymakers to decide on sustainable wheat production for food security in the region.

scholarly journals Review of Intelligent Control Systems for Natural Ventilation as Passive Cooling Strategy for UK Buildings and Similar Climatic Conditions

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4388
Author(s):  
Esmail Mahmoudi Saber ◽  
Issa Chaer ◽  
Aaron Gillich ◽  
Bukola Grace Ekpeti
Keyword(s):  
Control Systems ◽  
Natural Ventilation ◽  
Energy Use ◽  
Integrated Control ◽  
Climatic Conditions ◽  
Effective Control ◽  
Practical Implementation ◽  
Optimal Output ◽  
Heating And Cooling ◽  
Building Cooling

Natural ventilation is gaining more attention from architects and engineers as an alternative way of cooling and ventilating indoor spaces. Based on building types, it could save between 13 and 40% of the building cooling energy use. However, this needs to be implemented and operated with a well-designed and integrated control system to avoid triggering discomfort for occupants. This paper seeks to review, discuss, and contribute to existing knowledge on the application of control systems and optimisation theories of naturally ventilated buildings to produce the best performance. The study finally presents an outstanding theoretical context and practical implementation for researchers seeking to explore the use of intelligent controls for optimal output in the pursuit to help solve intricate control problems in the building industry and suggests advanced control systems such as fuzzy logic control as an effective control strategy for an integrated control of ventilation, heating and cooling systems.

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.

Dynamic Analysis of Tilting-Pad Journal Bearing—Influence of Pad Deformations

1994 ◽  
Vol 116 (3) ◽  
pp. 621-627 ◽  
Author(s):  
H. Desbordes ◽  
M. Fillon ◽  
C. Chan Hew Wai ◽  
J. Frene
Keyword(s):  
Film Thickness ◽  
Pressure Field ◽  
Journal Bearing ◽  
Maximum Pressure ◽  
Tilting Pad ◽  
Minimum Film Thickness ◽  
Dimensional Finite Element ◽  
The One ◽  
Tilting Pad Journal Bearing ◽  
Tilting Pad Journal Bearings

A theoretical nonlinear analysis of tilting-pad journal bearings is presented for small and large unbalance loads under isothermal conditions. The radial displacements of internal pad surface due to pressure field are determined by a two-dimensional finite element method in order to define the actual film thickness. The influence of pad deformations on the journal orbit, on the minimum film thickness and on the maximum pressure is studied. The effects of pad displacements are to decrease the minimum film thickness and to increase the maximum pressure. The orbit amplitude is also increased by 20 percent for the large unbalance load compared to the one obtained for rigid pad.

Treatment of frostbite in an open way (without dressings)

1937 ◽  
Vol 33 (1) ◽  
pp. 84-86
Author(s):  
V. A. Petrovykh
Keyword(s):  
Recovery Period ◽  
Climatic Conditions ◽  
The Other ◽  
Critical Approach ◽  
Tatar Strait ◽  
Other Hand ◽  
Number Of Patients ◽  
The One ◽  
Apparent Similarity ◽  
Methods Of Treatment

The harsh climatic conditions of the coast of the Tatar Strait make explainable the large number of patients with frostbite who passed under our supervision during the winter of 1935-36 and amounted to 2.8% (26 people) of the total contingent of inpatients. The variety of recommended methods for treating frostbite, on the one hand, and the relatively long recovery period for all of them, on the other hand, made us take a critical approach to the proposed methods of treatment. All currently existing methods are reduced to the treatment of frostbite areas with bandages; and on the locus morbi apply indifferent or slightly disinfecting ointments, or a similar property of a powder, or wipes moistened with slightly disinfecting solutions, for example, Sol. kalii hyperm. 1: 1000. The apparent similarity of the external manifestations of frostbite and burns inspired us with the idea of ​​conducting frostbite therapy in an "open way", which has long occupied a well-deserved place in the treatment of burns.

Acoustic Performance of Louvred Facades for Brisbane Domestic Airport: An Integrated Approach

2012 ◽  
Author(s):  
Frank Butera ◽  
Keith Hewett
Keyword(s):  
Natural Ventilation ◽  
Transmission Loss ◽  
Internal Noise ◽  
Building Design ◽  
Integrated Approach ◽  
External Noise ◽  
Climatic Conditions ◽  
Sustainable Building ◽  
Heating And Cooling ◽  
Airport Terminals

Maximising cross ventilation is a low energy method of naturally ventilating and providing heating and cooling to deep plan spaces. Significant reduction in the emission of greenhouse gases can be achieved through minimising the use of mechanical systems in regions with climatic conditions that support the use of natural ventilation. Arup has provided input into the design of a louvered facade for the control of external noise for Brisbane Domestic Airport. A full scale prototype facade was constructed and noise transmission loss measurements were undertaken. The results indicate that significant noise reduction can be achieved to enable compliance with the internal noise limits for airport terminals, whilst using natural ventilation. The findings from this research will directly benefit building designers and innovators in the pursuit of achieving sustainable building design.

The First Global Environmental Problem

2018 ◽  
pp. 38-54
Author(s):  
Hannah Holleman
Keyword(s):  
Arid Region ◽  
Climatic Conditions ◽  
Dust Bowl ◽  
Colonial Expansion ◽  
Global Environmental ◽  
Humid Region ◽  
The World ◽  
The Common ◽  
Ecological Relations ◽  
Economic Developments

This chapter challenges typical interpretations of the Dust Bowl and puts the disaster into a global frame, linking the past to the present. In so doing, the common roots of contemporary and past developments and struggles are revealed. The Dust Bowl was one spectacular instance of a global problem of soil erosion associated with capitalist colonial expansion. While the official interpretation suggests that agriculture suited for a humid region was imported to an arid region, precipitating the crisis, contemporaneous accounts illustrate how much larger the crisis was, tied up with specific social and economic developments that imposed new socio-ecological relations upon peoples of the world and upon the land irrespective of local climatic conditions. Ultimately, the common denominators across the world—from North to South America, Australia to Africa, and Southeast to East Asia—were not climate and geography, but capitalism and colonialism.

scholarly journals Improving Interior Environmental Quality Using Sustainable Design in Jordanian Hospital Bedrooms

2020 ◽  
Vol 9 (3) ◽  
pp. 443
Author(s):  
Saeed Hussein Alhmoud ◽  
Çiğdem Çağnan ◽  
Enis Faik Arcan
Keyword(s):  
Interior Design ◽  
Environmental Quality ◽  
Sustainable Design ◽  
Health Sector ◽  
Green Building ◽  
Climatic Conditions ◽  
Building Assessment ◽  
The World ◽  
Set Up ◽  
The One

As the wave of sustainability is sweeping across the major countries and cities of the world, the effect of the inevitable change is finding its way through to the health sector as well. Since the main functions of the hospital include healing the patient, it aims to provide adequate health services to people. Hospitals managers should strive to realize facilities that meet a certain level of demand. This study aims to present the interior environmental quality (IEQ) of bedrooms in Jordanian hospitals and propose a solution to improve indoor environment quality using sustainable design principles. A qualitative research methodology is used in this study. A comparative analysis is made between the original set up of the hospital buildings and the present conditions in which they are in. During the research, it was found that the design to be applied for a hospital should be following the healing environmental characteristics. Besides, the design of hospitals should be made with the climatic conditions of the area in mind. In the advanced countries of the world, hospitals are generally built with extensive research and important factors such as temperature, wind direction and humidity are taken into consideration. The design for a hospital building should be assessed according to the German Green Building Assessment (DGNB) criteria. It has been found that the one-bedroom is ideal for patients because it provides the necessary privacy and also greatly reduces the spread of the disease. In hygienic practices, there should be a first-class healing environment with evidence-based medical research. It was concluded that the practices involving the use of sustainable designs can be followed with the hints received from hospitals in the advanced countries of the world. Keywords: Jordan hospital; IEQ; bedroom; interior design; healthcare; green building assessment; DGNB

Small and Full-Scale Modeling for the Application of Wall Solar Chimneys

2016 ◽  
Author(s):  
David Park ◽  
Francine Battaglia
Keyword(s):  
Natural Ventilation ◽  
Velocity Ratio ◽  
Thermal Conditions ◽  
Ambient Air ◽  
Full Scale ◽  
Scale Model ◽  
Small Scale ◽  
Solar Chimney ◽  
Window Position ◽  
Pi Theorem

A solar chimney is a natural ventilation technique that has a potential to save energy consumption as well as to maintain the air quality in the building. However, studies of buildings are often challenging due to their large sizes. The objective of the current study was to determine relationships between small- and full-scale solar chimney system models. In the current work, computational fluid dynamics (CFD) was utilized to model different building sizes with a solar chimney system, where the computational model was validated with the experimental study of Mathur et al. The window, which controls entrainment of ambient air, was also studied to determine the effects of window position. Correlations for average velocity ratio and non-dimensional temperature were consistent regardless of window position. Buckingham pi theorem was employed to further non-dimensionalize the important variables. Regression analysis was conducted to develop a mathematical model to predict a relationship among all of the variables, where the model agreed well with simulation results with an error of 2.33%. The study demonstrated that the flow and thermal conditions in larger buildings can be predicted from the small-scale model.

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