Simulation of COVID-19 indoor emissions from coughing and breathing with air conditioning and mask protection effects

2021 ◽  
pp. 1420326X2110395 ◽  
Author(s):  
Carlo Cravero ◽  
Davide Marsano
Keyword(s):  
Air Conditioning ◽  
Vaccination Campaign ◽  
Ventilation System ◽  
Management Strategies ◽  
Air Conditioning System ◽  
Beneficial Effects ◽  
Mass Vaccination Campaign ◽  
Future Events ◽  
System Configurations ◽  
Different Characteristics

The COVID-19 infection has emerged as a disruptive pandemic at worldwide level. The study of the mechanism of contagion is one of the greatest challenges before a mass vaccination campaign that would protect populations. The study can support the development of knowledge and tools to develop possible strategies for containing its spread in future events. The saliva droplet aerosol expelled during breathing or coughing is the main cause for the propagation of the SARS-Cov-2. In this work, a URANS CFD approach was used to simulate the dispersion from the mouth of these particles in closed environments. The air conditioning system was considered. The conditions were varied to determine their impact on the diffusion of the aerosol. Lagrangian and Eulerian numerical approaches were used to model the coughing and the breathing events. These were validated with the puff theory, numerical and experimental results. A realistic case of a meeting room with two persons was simulated. Different characteristics of the expulsed aerosols and different ventilation system configurations were considered to demonstrate how these simulations can support management strategies for indoor occupation. Finally, the effect of the protective mask was introduced to quantify its beneficial effects to support safe indoor occupation.

scholarly journals Hierarchical Neighborhood Models for Ventilation System

2018 ◽  
Vol 7 (3.5) ◽  
pp. 24 ◽  
Author(s):  
A.M Shmyrin ◽  
N.M Mishachev ◽  
V.V Semina
Keyword(s):  
Air Conditioning ◽  
Ventilation System ◽  
Dust Emission ◽  
Environmental Safety ◽  
Optimal Operation ◽  
Energy Costs ◽  
Air Conditioning System ◽  
Cement Production ◽  
Neighborhood Models ◽  
Production Shop

Considering cement production, we deal with dust, associated with a non-optimal operation of the dust-free ventilation system in the clinker burning department. The optimally organized heating, ventilating, and air conditioning system in any type of production ensures the microclimate of the production premises, corresponding to the sanitary norms and rules, which contribute to the increase of the staff’s efficiency. In this paper, the questions of the neighborhood modeling of the heating, ventilating, and air conditioning system in the premises of the cement production shop are considered. A system for minimizing energy costs and reducing dust emission in the clinker burning shop is proposed, which allows increasing the environmental safety of production. 

scholarly journals Evaluation of Thermal Behavior of the Skeleton in a Green Building with the Aid of TABS

2019 ◽  
Vol 111 ◽  
pp. 01085
Author(s):  
Hiroshi Muramatsu ◽  
Tatsuo Nobe
Keyword(s):  
Heat Flux ◽  
Thermal Behavior ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Concrete Slab ◽  
Ventilation System ◽  
Office Building ◽  
Air Conditioning System ◽  
Indoor Thermal Environment

In this study, an office building in Japan that incorporates energy-saving features and environmental technologies was investigated. This office building features a green façade, natural ventilation, a concrete slab with no suspended ceilings, and thermo-active building systems. Two airconditioning systems were installed in this building—a ceiling radiation air-conditioning system and a whole floor-blow off air conditioning system. In addition, a natural ventilation system was installed. We surveyed the heat flux of the ceiling surface and indoor thermal environment of this building from 2015 through 2016. The ceiling using the heat storage amount of concrete maintains a constant temperature in the workplace during as well as after office hours. We also performed detailed measurements of the heat flux of the ceiling surface and indoor thermal environment in the summer of 2017. The results showed that the ceiling radiation air-conditioning system provided a stable thermal environment. Furthermore, we report that making use of the thermal behavior of the skeleton improved the operation of the ceiling radiation airconditioning system.

Optimization of Thermal Stability of Atrium Based on Computational Modeling

2016 ◽  
Vol 861 ◽  
pp. 353-360
Author(s):  
Aleš Rubina ◽  
Pavel Uher ◽  
Petr Blasinski
Keyword(s):  
Thermal Stability ◽  
Air Conditioning ◽  
Computer Modelling ◽  
Ventilation System ◽  
Air Conditioning System ◽  
Indoor Space ◽  
Central Air Conditioning ◽  
And Performance ◽  
Thermal Stability Of ◽  
Occupied Zone

The article deals with analysis of the heat balance and temperature microclimate of indoor space of a four-storey building atrium. With regard to the anticipated thermal loads in all functionally connected rooms, investor made a request to verify the thermal stability of the atrium before the implementation stage. Atrium and adjacent rooms are a geometrically complicated inner space which cannot be solved by analytical methods to ensure the required temperature conditions in occupied zone. This led to the creation of a mathematical model of the atrium with the current project solution. The result of the simulation of the existing solutions is that there is not complied desired air temperature in the occupied zone. For this reason, it was developed optimization of existing variant. Optimization was performed in steps as changing temperature of the central air conditioning system, changing number of units and performance of local refrigeration air conditioning. The conclusion of this paper is to evaluate the thermal profiles of temperature stratification in the atrium area and request the required cooling performance of the ventilation system. The article attempts to use computer modelling as a tool for the placement and performance design of ventilation equipment.

Analysis of Reconstruction in Terms of CO2 Concentration

2019 ◽  
Vol 808 ◽  
pp. 39-45
Author(s):  
Mária Budiaková
Keyword(s):  
Mechanical Ventilation ◽  
Air Quality ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Short Term ◽  
Air Conditioning System ◽  
The Poor ◽  
The University ◽  
Concentration Limits

The paper focuses on the analysis of reconstruction in terms of CO2 concentration. The reconstruction at the university included the exchange of windows. The original windows were exchanged for the modern wood tight windows. Providing CO2 concentration in the interiors of a university is immensely important for the students of the university. Not exceeding CO2 concentration limits is necessary not only for the physiological needs of students but also for the required performance of students. Teaching is conducted during the whole day in the researched university schoolroom. The short-term natural ventilation during the breaks is noticeably not sufficient. After 15 minutes from the beginning of the lesson, students started complaining about the air quality and they had to open the windows. To point out the unsustainable state of the poor air quality during the day-long teaching and to be able to prove the officials the importance of the continuation of the reconstruction by building mechanical ventilation or air conditioning system, there were carried out the experimental measurements in the schoolroom. The device Testo 480 was used for the measurements. Obtained values of CO2 concentration are presented in the charts. Interestingly, this reconstruction significantly decreased the air quality. The admissible values of CO2 concentration were exceeded after the first hours of teaching. These values were worsening with each additional hour of teaching. Therefore, another reconstruction is needed to enable the transition from natural ventilation to the mechanical ventilation system. In the conclusion of this paper, there are principles how to design new schoolrooms. Furthermore, there are presented recommendations how to operate the existing schoolrooms.

DESIGN OF THE AIR CONDITIONING SYSTEM OF THE ROOM FOR MUSHROOM GROWING

2020 ◽  
Author(s):  
U.I. Babenkov ◽  
◽  
V.V. Romanov ◽  
G.A. Galka ◽  
E.S. Zhelonkina
Keyword(s):  
Technological Process ◽  
Heat Sink ◽  
Air Conditioning ◽  
Ventilation System ◽  
Calculated Data ◽  
Lighting System ◽  
Air Conditioning System ◽  
Refrigeration Equipment ◽  
Heat Influx ◽  
Oyster Mushrooms

Based on the analysis of the technological process and the requirements for the growth of oyster mushrooms, the article examined: the main errors in the design of the mushroom farm, calculated the heat influx and heat sink of the production room, selected an air conditioning scheme for summer and winter modes, developed cabinets for placing mushroom blocks, designed and the lighting system was designed, the design and calculation of the ventilation system was performed. Based on the calculated data, the main additional refrigeration equipment, air conditioning system was selected, equipment for the lighting system was selected. The aim of this work is to design an air conditioning system for a room with a year-round cycle of growth of oyster mushrooms.

scholarly journals Low Cost Green Retrofit for Office

2019 ◽  
Vol 8 (2) ◽  
pp. 3155-3161 ◽  
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Low Cost ◽  
Ventilation System ◽  
Lighting System ◽  
Air Conditioning System ◽  
Potted Plants ◽  
Building Retrofit ◽  
Significant Attention

Building retrofit programme has received significant attention in recent years. This article aims to make a contribution towards low cost green retrofit for office application. The retrofit options suggested in this study includes ventilation system, efficient lighting system, potted plants for better indoor air quality and thermal insulation to walls and roof. The detailed analysis of proposed ventilation system is included in the present study. The comparison between proposed ventilation system with existing air conditioning system is also analyzed. The study demonstrates an efficient way towards achieving low cost green retrofit. The outcomes of this case study will increase the confidence among stakeholders in promoting energy conservation and sustainability.

scholarly journals PIV measurement of a jet from a gasper in an aircraft cabin mockup

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
João Henrique Antoniazzi de Gouveia ◽  
Jurandir Itizo Yanagihara
Keyword(s):  
Air Conditioning ◽  
High Speed ◽  
Ventilation System ◽  
Field Studies ◽  
Breathing Zone ◽  
Entrainment Ratio ◽  
Air Conditioning System ◽  
Piv Measurement ◽  
Personalized System ◽  
Commercial Aircrafts

The air conditioning system of most commercial aircrafts consists of a main system, which operates on the principle of mix ventilation, and a personalized system called gasper. Field studies show that passengers prefer to keep gasper parcially open or redirect it away from the head due to the discomfort. Therefore, there is a demand to characterize the flow of this device for future improvements. In this way, the present work aims to experimentally study the gasper jet inside a real cabin mockup using PIV. The results indicate that passengers are subjected to a high speed jet and the air in their breathing zone is mostly supplied by the mixed ventilation system due to the large entrainment ratio.

Research on Characteristics of Microbe Spatiotemporal Distribution in Indoor Air

2014 ◽  
Vol 955-959 ◽  
pp. 253-256
Author(s):  
Zhe Hua Du ◽  
Xin Lin
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Indoor Environment ◽  
Ventilation System ◽  
Weather Condition ◽  
Spatiotemporal Distribution ◽  
Dust Particles ◽  
Airborne Microorganisms ◽  
Air Conditioning System ◽  
Environment Condition

The review focuses on the progresses of air microbes in indoor environment, including their sources, sorts, influence of human body health, spread regulation and spatiotemporal distribution characteristics. Most airborne microorganisms attached to the dust particles, which is present in the air in the form of aerosol .The distribution of microbe is related with indoor environment condition in the air. The factor which influences it to distribute mainly includes temperature, degree of humidity, wind velocity and weather condition etc. Air microbe is bred easily in ventilation and air conditioning system. The growth of microbe has a tremendous relation with the ventilation and air condition. The distribution of microorganisms in different regions, different buildings and different ventilation system is different from each other.

Detection and Analysis of Microbial Contamination in Central Air Conditioning System of a University

2012 ◽  
Vol 610-613 ◽  
pp. 661-664
Author(s):  
Hui Xing Li ◽  
Bei Ni Li ◽  
Geng Geng ◽  
Wei Xiao ◽  
Wei Wang
Keyword(s):  
Air Conditioning ◽  
Microbial Contamination ◽  
Ventilation System ◽  
Inner Product ◽  
Public Places ◽  
Air Conditioning System ◽  
Surface Dust ◽  
Photo Catalysis ◽  
Air Ventilation ◽  
Central Air Conditioning

Objective: Test the wind pipe dust and microorganism pollution status in the central air conditioning system of public buildings in the teaching area.Analysis of microbial pollution of the related factors.Methods:Sampling 6 functionally different area in the teaching building,using the microbiology analysis method on air conditioning system of blower tube surface dust pollution of microorganism detection,and the use of TiO2 photo catalyst purification mechanism on microbial contamination control.Results:on the basis of"centralized air ventilation system in public places sanitary specification",teaching areas of central air conditioning system of dust amount met the requirement basically.Bacterial concentrations generally beyond the standard,fungal concentration accords with the standard.The Method using TiO2 photo catalysis sterilization was proposed. Conclusion:Teaching of regional air conditioning pipe inner product dust weight is relatively large.Microbial pollution is serious.It is necessary that cleaning air conditioning system timely and using TiO2 Photocatalyst purification mechanism for killing air duct surface dust microorganism.

Design of Air-Conditioning System and Ventilation System in Web Press Workshop of One Printing Plant

2012 ◽  
Vol 256-259 ◽  
pp. 2640-2643
Author(s):  
Zi Jing Zhang ◽  
Bo Wen ◽  
Zhi Dong Lv
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Waste Heat ◽  
Ventilation System ◽  
Good Method ◽  
Large Space ◽  
Total Load ◽  
Air Conditioning System ◽  
Saving Effect ◽  
Press Equipment

Air-conditioning and ventilation system which control temperature and humidity was designed in this paper. Its aim was to ensure the production process and meet the comfort requirements of workers. Considering that web press equipment load account for large proportion of the total load, we separated out the area of web press and the waste heat was discharged by ventilation system. We adopted Stratified air conditioning on the remaining area because the whole workshop is large space. By means of calculation, energy saving rate of stratified air conditioning system is 25.6% and the refrigerating capacity is reduced by this way of design. Energy-saving effect is remarkable. So it’s a good method to energy conservation.

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