scholarly journals Modeling of Ventilation Efficiency

Air Quality ◽  
10.5772/9758 ◽  
2010 ◽  
Author(s):  
Mahmoud Bady
Keyword(s):  
Ventilation Efficiency

scholarly journals Impact of Air Infiltration on IAQ and Ventilation Efficiency in Higher Educational Classrooms in Spain

2021 ◽  
Vol 13 (12) ◽  
pp. 6875
Author(s):  
Irene Poza-Casado ◽  
Raquel Gil-Valverde ◽  
Alberto Meiss ◽  
Miguel Ángel Padilla-Marcos
Keyword(s):  
Natural Ventilation ◽  
Well Being ◽  
Cold Season ◽  
Climate Conditions ◽  
Air Infiltration ◽  
Ventilation Efficiency ◽  
Educational Buildings ◽  
Set Up ◽  
Total Volatile Organic Compounds ◽  
The Impact

Indoor air quality (IAQ) in educational buildings is a key element of the students’ well-being and academic performance. Window-opening behavior and air infiltration, generally used as the sole ventilation sources in existing educational buildings, often lead to unhealthy levels of indoor pollutants and energy waste. This paper evaluates the conditions of natural ventilation in classrooms in order to study how climate conditions affect energy waste. For that purpose, the impact of the air infiltration both on the IAQ and on the efficiency of the ventilation was evaluated in two university classrooms with natural ventilation in the Continental area of Spain. The research methodology was based on site sensors to analyze IAQ parameters such as CO2, Total Volatile Organic Compounds (TVOC), Particulate Matter (PM), and other climate parameters for a week during the cold season. Airtightness was then assessed within the classrooms and the close built environment by means of pressurization tests, and infiltration rates were estimated. The obtained results were used to set up a Computational Fluid Dynamics (CFD) model to evaluate the age of the local air and the ventilation efficiency value. The results revealed that ventilation cannot rely only on air infiltration, and, therefore, specific controlled ventilation strategies should be implemented to improve IAQ and to avoid excessive energy loss.

What is ventilation efficiency?

1981 ◽  
Vol 16 (2) ◽  
pp. 123-135 ◽  
Author(s):  
Mats Sandberg
Keyword(s):  
Ventilation Efficiency

Different ventilation strategies alter surfactant responses in preterm rabbits

1992 ◽  
Vol 73 (5) ◽  
pp. 2089-2096 ◽  
Author(s):  
E. D. Rider ◽  
A. H. Jobe ◽  
M. Ikegami ◽  
B. Sun
Keyword(s):  
Ventilation Strategy ◽  
Positive End Expiratory Pressure ◽  
Lung Volumes ◽  
Low Tidal Volume ◽  
Volume Ventilation ◽  
Ventilation Efficiency ◽  
Ventilation Strategies ◽  
Peak Pressures ◽  
Better Than

The effect of ventilation strategy on in vivo function of different surfactants was evaluated in preterm rabbits delivered at 27 days gestational age and ventilated with either 0 cmH2O positive end-expiratory pressure (PEEP) at tidal volumes of 10–11 ml/kg or 3 cmH2O PEEP at tidal volumes of 7–8 ml/kg after treatment with one of four different surfactants: sheep surfactant, the lipids of sheep surfactant stripped of protein (LH-20 lipid), Exosurf, and Survanta. The use of 3 cmH2O PEEP decreased pneumothoraces in all groups except for the sheep surfactant group where pneumothoraces increased (P < 0.01). Ventilatory pressures (peak pressures - PEEP) decreased more with the 3 cmH2O PEEP, low-tidal-volume ventilation strategy for Exosurf-, Survanta-, and sheep surfactant-treated rabbits (P < 0.05), whereas ventilation efficiency indexes (VEI) improved only for Survanta- and sheep surfactant-treated rabbits with 3 cmH2O PEEP (P < 0.01). Pressure-volume curves for sheep surfactant-treated rabbits were better than for all other treated groups (P < 0.01), although Exosurf and Survanta increased lung volumes above those in control rabbits (P < 0.05). The recovery of intravascular radiolabeled albumin in the lungs and alveolar washes was used as an indicator of pulmonary edema. Only Survanta and sheep surfactant decreased protein leaks in the absence of PEEP, whereas all treatments decreased labeled albumin recoveries when 3 cmH2O PEEP was used (P < 0.05). These experiments demonstrate that ventilation style will alter a number of measurements of surfactant function, and the effects differ for different surfactants.

scholarly journals Analysis on Ventilation Efficiency of Standard Duck House using Computational Fluid Dynamics

2015 ◽  
Vol 57 (5) ◽  
pp. 51-60 ◽  
Author(s):  
Uk-Hyeon Yeo ◽  
Ye-Seul Jo ◽  
Kyeong-Seok Kwon ◽  
Tae-Hwan Ha ◽  
Se-Jun Park ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Ventilation Efficiency

scholarly journals Research on the Influence of the Distribution Pattern of Building Clusters in Coastal Areas on Wind Environment -Focused on Busan area in Korea

2021 ◽  
Vol 308 ◽  
pp. 02010
Author(s):  
Yang Huimin ◽  
Zhao Shuwen ◽  
Kim Chulsoo
Keyword(s):  
Thermal Environment ◽  
Simulation Software ◽  
Fluid Simulation ◽  
Wind Environment ◽  
Environment Quality ◽  
Ventilation Efficiency ◽  
Urban Thermal Environment ◽  
The City ◽  
Public Environment

With the development of urbanization, the heat island phenomenon has led to further deterioration of the urban thermal environment, resulting in wind environment differences. To study the thermal environment of the city, this paper takes the Busan area in South Korea as the research object and analyzes the connection between the layout of buildings and the wind environment based on the microscopic wind environment characteristics of the coastal area using CFD air-fluid simulation software and suggests that the monsoon influence brought by the coastal currents should be paid attention to, the layout of wind-oriented building groups should be improved, urban air ducts should be established to enhance the ventilation efficiency, and the wind environment of the urban public environment and buildings should be guaranteed. The wind environment quality of urban public environment and indoor environment should be ensured.

Computational fluid dynamics evaluation of the furniture arrangement for ventilation efficiency

2018 ◽  
Vol 39 (5) ◽  
pp. 557-571 ◽  
Author(s):  
Susana Hormigos-Jimenez ◽  
Miguel Ángel Padilla-Marcos ◽  
Alberto Meiss ◽  
Roberto Alonso Gonzalez-Lezcano ◽  
Jesús Feijó-Muñoz
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Energy Efficiency ◽  
Indoor Air ◽  
Tracer Gas ◽  
Steady State Method ◽  
Air Movement ◽  
Ventilation Efficiency ◽  
State Method ◽  
Furniture Arrangement

People spend most of their time indoors; therefore, maintaining a good indoor air quality and meeting the requirements of comfort and energy efficiency are essential. One of the most widespread strategies to achieve this objective is improving ventilation efficiency; therefore, the main aim of this study was to show an optimization of the ventilation efficiency, in a specific room, considering 47 variations (case studies) in the furniture arrangement. For this purpose, a numerical analysis using computational fluid dynamics techniques, validated by the tracer gas decay technique, was used to assess the distribution of the age of air within the space. The concept of “age of air” was implemented in the computational fluid dynamics code through user-defined functions, using the steady-state method based on the resolution of a transport equation for an additional scalar. Variations up to 5.75% in the ventilation efficiency between the cases studied have been achieved. It is concluded that an improvement up to 1.65% can be obtained when the elements of the study are introduced in a way that facilitates the air movement towards the exhaust; therefore, improvement of the ventilation efficiency through specific furniture distributions is possible, although not significant, according to the outcomes.

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