scholarly journals Naturally ventilated industrial sheds: an investigation about the influence of wind direction in flow rate efficiency in continuous roof vents

2021 ◽  
Vol 36 (4) ◽  
Author(s):  
B. Carmagos ◽  
H. De Souza ◽  
A. Gomes ◽  
A. Ladeira ◽  
R. Dos Reis ◽  
...  
Keyword(s):  
Flow Rate ◽  
Indoor Air ◽  
Wind Direction ◽  
Natural Ventilation ◽  
Climatic Conditions ◽  
Internal Source ◽  
Internal Temperature ◽  
Healthy Environment ◽  
Belo Horizonte ◽  
Roof Vents

Natural ventilation portrays an effective technique for lowering the internal temperature, without spending electricity, and directly contributes to the renewal of indoor air by establishing a healthy environment for workers. Given this, it is usual to have air vent openings located at the top of the roof (continuous roof vents), in addition to those present on the facades of sheds. In naturally ventilated buildings, it is recommended to give due importance to the provision of these openings, since depending on the proposed arrangement, the wind may or may not help in the effectiveness of this strategy. In this work, it is evaluated via computer simulation (EnergyPlus, version 8.7.0), for the climatic conditions of the city of Belo Horizonte/Brazil, the influence of the wind direction in the flow rate of indoor air through the ridge vents, of the longitudinal and transversal type, present in industrial sheds endowed with an internal source of high-intensity heat release. The results obtained show that the flow rate has a symmetrical behavior in the openings of the longitudinal continuous roof vent, that is, when an opening is with the maximum outflow of the internal air, the opening opposite the predominant wind direction is acting as an entry point for the air external. The transverse continuous roof vents are more sensitive about the wind direction since they are positioned perpendicular to the building. The best result found is for the wind situation occurring parallel to the shed, obtaining a reduction in the internal temperature of up to 1°C, an increase in the rate of air changes per hour, in the internal environment, at 1acph, and an increase of up to 10,7% in the volume of air infiltrated into the shed.

scholarly journals Naturally ventilated industrial sheds: an investigation about the influence of wind direction in flow rate efficiency in continuous roof vents

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
B. Camargos ◽  
H. De Souza ◽  
A. Gomes ◽  
A. Ladeira ◽  
R. Dos Reis ◽  
...  
Keyword(s):  
Flow Rate ◽  
Indoor Air ◽  
Wind Direction ◽  
Natural Ventilation ◽  
Climatic Conditions ◽  
Internal Source ◽  
Internal Temperature ◽  
Healthy Environment ◽  
Belo Horizonte ◽  
Roof Vents

Natural ventilation portrays an effective technique for lowering the internal temperature, without spending electricity, and directly contributes to the renewal of indoor air by establishing a healthy environment for workers. Given this, it is usual to have air vent openings located at the top of the roof (continuous roof vents), in addition to those present on the facades of sheds. In naturally ventilated buildings, it is recommended to give due importance to the provision of these openings, since depending on the proposed arrangement, the wind may or may not help in the effectiveness of this strategy. In this work, it is evaluated via computer simulation (EnergyPlus, version 8.7.0), for the climatic conditions of the city of Belo Horizonte/Brazil, the influence of the wind direction in the flow rate of indoor air through the ridge vents, of the longitudinal and transversal type, present in industrial sheds endowed with an internal source of high-intensity heat release. The results obtained show that the flow rate has a symmetrical behavior in the openings of the longitudinal continuous roof vent, that is, when an opening is with the maximum outflow of the internal air, the opening opposite the predominant wind direction is acting as an entry point for the air external. The transverse continuous roof vents are more sensitive about the wind direction since they are positioned perpendicular to the building. The best result found is for the wind situation occurring parallel to the shed, obtaining a reduction in the internal temperature of up to 1°C, an increase in the rate of air changes per hour, in the internal environment, at 1acph, and an increase of up to 10,7% in the volume of air infiltrated into the shed.

scholarly journals Spatial distributions of airborne dust in a cows barn exposed to influence of different ventilation rates

2013 ◽  
Vol 29 (2) ◽  
pp. 373-383
Author(s):  
G. Topisirovic ◽  
D.V. Petrovic ◽  
R. Maletic
Keyword(s):  
Flow Rate ◽  
Indoor Air ◽  
Rotation Rate ◽  
Natural Ventilation ◽  
Electronic Control Unit ◽  
Air Flow ◽  
Control Unit ◽  
Dust Particles ◽  
Airborne Dust ◽  
Stability And Instability

Information on the concentration of dust particles is an important microclimate parameter that characterizes the local environmental quality of each livestock building. Increased concentration of dust particles primarily affects the indoor air quality and, consequently, the animal and workers health. Among many others, ventilation rate is a vital parameter that controls the spatial distribution of airborne dust particles in livestock buildings. This was the main motive for authors of this paper to research the influence of rotation rate of under-roof axial fans (i.e. the air flow rate) on airborne dust particles distribution crossover the barn specified for tied cows breeding. During a series of performed experiments, six different air flow rates have been maintained in the range between 0 m3?h-1 and 48000 m3?h-1. Flow rate has been controlled by special electronic control unit, which provided six different rotation rates of two under-roof fans, including the neutral regime (natural ventilation only). Measurements have been performed at four typical height levels (0,5 m; 1,0 m; 1,5 m and 2,0 m), cross-over the three lateral and four longitudinal characteristic building sections. Consequently, 48 measuring points were appropriately selected, in order to cover the indoor space in adequate way. Comparative analysis of air flow velocities and dust concentrations showed that this fan setup may give satisfactory results under adequate operational regime. Certain working regimes were recommended for use, and the third rotation rate step, generating the airflow of 37300 m3?h-1 or indoor air exchange level of approximately 25 h-1, has been found as the most suitable. Projekat Ministarstva nauke Republike Srbije, br. TR31086: Optimization of technological procedures and zoo-technical resources on farmsin purpose of milk production sustainability improvement, br. TR 31051: Improvement of biotechnological procedures as a function of rational utilizationof energy, agricultural products productivity and quality increase, br. III46009: Improvement and development new technological procedures in production ofanimal products, to achieve high quality and safe competitive products inmarket i br. OI 174011: Dynamical stability and instability of mechanical systems exposed to stochasticdisturbances

scholarly journals Research on the Impact of Wind Angles on the Residential Building Energy Consumption

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Zou Huifen ◽  
Yang Fuhua ◽  
Zhang Qian
Keyword(s):  
Energy Consumption ◽  
Heat Loss ◽  
Indoor Air ◽  
Wind Direction ◽  
Natural Ventilation ◽  
Building Energy ◽  
Simulation Software ◽  
Outdoor Environment ◽  
Building Energy Consumption ◽  
The Impact

Wind angles affect building’s natural ventilation and also energy consumption of the building. In winter, the wind direction in the outdoor environment will affect heat loss of the building, while in summer the change of wind direction and speed in the outdoor environment will affect the building’s ventilation and indoor air circulation. So, making a good deal with the issue of the angle between local buildings and the dominant wind direction can effectively solve the winter and summer ventilation problems. Thereby, it can enhance the comfort of residential person, improve indoor air quality, solve heat gain and heat loss problems in winter and summer in the severely cold and cold regions, and reduce building energy consumption. The simulation software CFD and energy simulation software are used in the paper. South direction of the building is the prototype of the simulation. The angle between the direction of the building and the outdoor environment wind is changed sequentially. Energy consumption under different wind angle conditions is compared with each other. Combined with natural ventilation under various wind angles, the paper gives the best recommended solution of building direction in Shenyang.

scholarly journals An Investigation on Natural Window Ventilation: Improving Indoor Air Quality and Energy Efficiency in an Office Building

2021 ◽  
Author(s):  
Emine Şen ◽  
◽  
Touraj Ashrafian ◽  
Keyword(s):  
Energy Efficiency ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Air Temperature ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Indoor Air Pollution ◽  
Climatic Conditions ◽  
Office Building ◽  
Building Energy Efficiency

With the increment in time spent indoors, the contingence between building occupants and indoor air pollution has been lengthened. Accordingly, indoor air quality became a significant factor since the poor conditions can influence the occupants’ health and efficiency. Indoor air quality is mainly concerned with physical and thermophysical factors in conditioned environments and is related to occupants’ satisfaction levels on a variety of variables such as fresh air adequacy, air temperature, odor, humidity, and air velocity. This paper aims to investigate natural ventilation occupant-control methods to improve indoor air quality and increase building energy efficiency considering clean air intake levels and indoor air temperature levels. For this, variables related to climatic conditions, ventilation systems, and occupant’s control on window opening were investigated to provide healthy and liveable conditions. To comply with these goals, in an open-plan office building, the levels of indoor air quality were determined with the help of DesignBuilder simulation by comparing obtained values under different case modeling variations.

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.

Simulation of the internal temperature in the Passol Laboratory, University of Debrecen

2012 ◽  
Vol 3 (1) ◽  
pp. 63-73 ◽  
Author(s):  
I. Csáky ◽  
F. Kalmár
Keyword(s):  
Temperature Variation ◽  
Air Temperature ◽  
Indoor Air ◽  
Storage Capacity ◽  
Building Structures ◽  
Internal Temperature ◽  
The One ◽  
Heavy Structure ◽  
East West ◽  
Made In

Abstract Nowadays the facades of newly built buildings have significant glazed surfaces. The solar gains in these buildings can produce discomfort caused by direct solar radiation on the one hand and by the higher indoor air temperature on the other hand. The amplitude of the indoor air temperature variation depends on the glazed area, orientation of the facade and heat storage capacity of the building. This paper presents the results of a simulation, which were made in the Passol Laboratory of University of Debrecen in order to define the internal temperature variation. The simulation proved that the highest amplitudes of the internal temperature are obtained for East orientation of the facade. The upper acceptable limit of the internal air temperature is exceeded for each analyzed orientation: North, South, East, West. Comparing different building structures, according to the obtained results, in case of the heavy structure more cooling hours are obtained, but the energy consumption for cooling is lower.

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 Effects of Climatic Conditions, Season and Environmental Factors on CO2 Concentrations in Naturally Ventilated Primary Schools in Chile

2021 ◽  
Vol 13 (8) ◽  
pp. 4139
Author(s):  
Muriel Diaz ◽  
Mario Cools ◽  
Maureen Trebilcock ◽  
Beatriz Piderit-Moreno ◽  
Shady Attia
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Primary Schools ◽  
Co2 Concentration ◽  
Building Design ◽  
Climatic Conditions ◽  
Indoor Environmental Quality ◽  
Co2 Concentrations ◽  
The Impact

Between the ages of 6 and 18, children spend between 30 and 42 h a week at school, mostly indoors, where indoor environmental quality is usually deficient and does not favor learning. The difficulty of delivering indoor air quality (IAQ) in learning facilities is related to high occupancy rates and low interaction levels with windows. In non-industrialized countries, as in the cases presented, most classrooms have no mechanical ventilation, due to energy poverty and lack of normative requirements. This fact heavily impacts the indoor air quality and students’ learning outcomes. The aim of the paper is to identify the factors that determine acceptable CO2 concentrations. Therefore, it studies air quality in free-running and naturally ventilated primary schools in Chile, aiming to identify the impact of contextual, occupant, and building design factors, using CO2 concentration as a proxy for IAQ. The monitoring of CO2, temperature, and humidity revealed that indoor air CO2 concentration is above 1400 ppm most of the time, with peaks of 5000 ppm during the day, especially in winter. The statistical analysis indicates that CO2 is dependent on climate, seasonality, and indoor temperature, while it is independent of outside temperature in heated classrooms. The odds of having acceptable concentrations of CO2 are bigger when indoor temperatures are high, and there is a need to ventilate for cooling.

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.

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