The impact of natural ventilation on airborne biocontaminants: a study on COVID-19 dispersion in an open office

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Günsu Merin Abbas ◽  
Ipek Gursel Dino
Keyword(s):  
Indoor Air ◽  
Natural Ventilation ◽  
Infection Risk ◽  
Content Type ◽  
Air Contamination ◽  
Simulation Based ◽  
Time Of Infection ◽  
Free Running ◽  
The Impact ◽  
Open Office

PurposeBiocontaminants represent higher risks to occupants' health in shared spaces. Natural ventilation is an effective strategy against indoor air biocontamination. However, the relationship between natural ventilation and indoor air contamination requires an in-depth investigation of the behavior of airborne infectious diseases, particularly concerning the contaminant's viral and aerodynamic characteristics. This research investigates the effectiveness of natural ventilation in preventing infection risks for coronavirus disease (COVID-19) through indoor air contamination of a free-running, naturally-ventilated room (where no space conditioning is used) that contains a person having COVID-19 through building-related parameters.Design/methodology/approachThis research adopts a case study strategy involving a simulation-based approach. A simulation pipeline is implemented through a number of design scenarios for an open office. The simulation pipeline performs integrated contamination analysis, coupling a parametric 3D design environment, computational fluid dynamics (CFD) and energy simulations. The results of the implemented pipeline for COVID-19 are evaluated for building and environment-related parameters. Study metrics are identified as indoor air contamination levels, discharge period and the time of infection.FindingsAccording to the simulation results, higher indoor air temperatures help to reduce the infection risk. Free-running spring and fall seasons can pose higher infection risk as compared to summer. Higher opening-to-wall ratios have higher potential to reduce infection risk. Adjacent window configuration has an advantage over opposite window configuration. As a design strategy, increasing opening-to-wall ratio has a higher impact on reducing the infection risk as compared to changing the opening configuration from opposite to adjacent. However, each building setup is a unique case that requires a systematic investigation to reliably understand the complex airflow and contaminant dispersion behavior. Metrics, strategies and actions to minimize indoor contamination risks should be addressed in future building standards. The simulation pipeline developed in this study has the potential to support decision-making during the adaptation of existing buildings to pandemic conditions and the design of new buildings.Originality/valueThe addressed need of investigation is especially crucial for the COVID-19 that is contagious and hazardous in shared indoors due to its aerodynamic behavior, faster transmission rates and high viral replicability. This research contributes to the current literature by presenting the simulation-based results for COVID-19 as investigated through building-related and environment-related parameters against contaminant concentration levels, the discharge period and the time of infection. Accordingly, this research presents results to provide a basis for a broader understanding of the correlation between the built environment and the aerodynamic behavior of COVID-19.

scholarly journals Window operation behaviour and indoor air quality during lockdown: A monitoring-based simulation-assisted study in London

2021 ◽  
pp. 014362442110177
Author(s):  
Farhang Tahmasebi ◽  
Yan Wang ◽  
Elizabeth Cooper ◽  
Daniel Godoy Shimizu ◽  
Samuel Stamp ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Probabilistic Models ◽  
Performance Model ◽  
Outdoor Environment ◽  
Ventilation Strategies ◽  
The Impact

The Covid-19 outbreak has resulted in new patterns of home occupancy, the implications of which for indoor air quality (IAQ) and energy use are not well-known. In this context, the present study investigates 8 flats in London to uncover if during a lockdown, (a) IAQ in the monitored flats deteriorated, (b) the patterns of window operation by occupants changed, and (c) more effective ventilation patterns could enhance IAQ without significant increases in heating energy demand. To this end, one-year’s worth of monitored data on indoor and outdoor environment along with occupant use of windows has been used to analyse the impact of lockdown on IAQ and infer probabilistic models of window operation behaviour. Moreover, using on-site CO2 data, monitored occupancy and operation of windows, the team has calibrated a thermal performance model of one of the flats to investigate the implications of alternative ventilation strategies. The results suggest that despite the extended occupancy during lockdown, occupants relied less on natural ventilation, which led to an increase of median CO2 concentration by up to 300 ppm. However, simple natural ventilation patterns or use of mechanical ventilation with heat recovery proves to be very effective to maintain acceptable IAQ. Practical application: This study provides evidence on the deterioration of indoor air quality resulting from homeworking during imposed lockdowns. It also tests and recommends specific ventilation strategies to maintain acceptable indoor air quality at home despite the extended occupancy hours.

Renovation in hospitals: a case study on the use of control cubes for local repairs in health-care facilities

2020 ◽  
Vol 18 (3) ◽  
pp. 247-257
Author(s):  
Ehsan Mousavi ◽  
Vivek Sharma ◽  
Dhaval Gajjar ◽  
Shervin Shoai Naini
Keyword(s):  
Health Care ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Health Care Facilities ◽  
Repair Work ◽  
Content Type ◽  
Care Facilities ◽  
Pathogenic Agents ◽  
The Impact

Purpose The purpose of this study is to evaluate the effectiveness of the control cubes for dust control in health-care facilities. Research shows that more than 80% of pathogenic agents in hospitals are spread into the air, where they either remain airborne or deposit on the surface. At the same time, renovation and repair activities, including regular maintenance, are a necessity in active health-care facilities and a multitude of studies have documented their impact on indoor air quality. The dust that is generated by construction activities may potentially carry pathogenic agents, varying from coarse particles (≤10 µm, PM10) to fine particles (≤2.5 µm, PM2.5), including airborne bacteria, and fungal spores linked to high patient mortality in immune-compromised patients. Design/methodology/approach This study measures the impact and effectiveness of one such preventative measure, namely, the control cube (CC), on air quality during renovation and repair. CC is a temporary structure, typically made from stainless steel, around the local repair zone to minimize the spread of dust and potential microorganisms. The current paper presents a comparative analysis to identify the effectiveness of a CC equipped with the high-efficiency particulate filtration (HEPA) filter in a hospital setting by simulating construction renovation and repair work. Findings A baseline was established to measure the effectiveness of CCs and the impact of negative pressure on the indoor air quality in a hospital during simulated renovation work. Results showed that CCs are very effective in minimizing the spread of dust due to construction activities in the hospital. However, it is imperative to ensure that the air inside the CC is cleaned via filtration. Originality/value CCs are very effective, and this paper investigates the best approach for facility managers to implement this strategy.

A numerical investigation on the impacts of voids combinations on natural ventilation of high-rise residential building

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hamza Laloui ◽  
Noor Hanita Abdul Majid ◽  
Aliyah Nur Zafirah Sanusi
Keyword(s):  
Thermal Comfort ◽  
Indoor Air ◽  
Design Methodology ◽  
Natural Ventilation ◽  
Residential Building ◽  
Air Velocity ◽  
Content Type ◽  
High Rise ◽  
Living Unit ◽  
Ventilation Performance

Purpose This paper aims to investigate the impacts of introducing voids combinations on natural ventilation performance in high-rise residential building living unit. Design/methodology/approach This study was carried out through field measurement and computational fluid dynamics methods. The parameters of the study are void types and sizes, and a wind angle was used to formulate case studies. Findings The results indicate that the provision of a single-sided horizontal void larger by 50% increase the indoor air velocity performance up to 322.37% to 0.471 m/s in the living unit and achieves the required velocity for thermal comfort. Originality/value Passive design features are the most desirable techniques to enhance natural ventilation performance in the high-rise residential apartments for thermal comfort and indoor air quality purposes.

Productivity paradox? The impact of office redesign on employee productivity

2018 ◽  
Vol 67 (9) ◽  
pp. 1918-1939 ◽  
Author(s):  
Erlinda N. Yunus ◽  
Erni Ernawati
Keyword(s):  
Mixed Method ◽  
Quantitative Research ◽  
Educational Institution ◽  
Work Productivity ◽  
Employee Productivity ◽  
Content Type ◽  
Future Studies ◽  
The Impact ◽  
The Relationship ◽  
Open Office

Purpose The purpose of this paper is twofold: first, to investigate the relationship between office redesign and employee productivity; and second to highlight the impact of privacy on work productivity across different generations. Design/methodology/approach This study examines open-office policy more comprehensively by integrating socio-behavioral and physical aspects of the office, and by using a mixed-method approach that incorporates most significant change, factor analysis and hierarchical regression analysis. Using a census method, the respondents were all consultants and trainers in an educational institution who were experiencing office design changes from a combi, cellular-like office to a more open, non-territorial office. Findings Three variables emerged as impacts of office redesign perceived by respondents: friendship, collaboration and privacy. Collaboration and privacy exert a positive influence on work productivity, while friendship does not. The relationship between privacy and work productivity is stronger for the Generation Y than for senior employees, namely, the Baby Boomers and Generation X. Research limitations/implications This study examines the impacts of office redesign in one organization. Future studies should advance the findings by empirically testing the theoretical model in broader contexts. Future studies could also enrich the literature by bringing cultural aspects into the discussion and comparing Asian-based and European or Western-based findings. Practical implications For Gen Y employees who prefer freedom, mobility and flexibility to personalization in their workplace, the open office could be a better solution for organizations that aim for both work productivity and efficiency. Originality/value This study provides an empirical value by using a mixed method of qualitative and quantitative research. This study further contrasts the different perspectives of an office redesign between younger and older generations.

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.

Window geometry impact on a room's wind comfort

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Reza Fallahtafti ◽  
Mohammadjavad Mahdavinejad
Keyword(s):  
Wind Velocity ◽  
Natural Ventilation ◽  
Control Volume ◽  
Simple Algorithm ◽  
Small Scale ◽  
Solar Absorption ◽  
Content Type ◽  
Velocity Magnitude ◽  
Architectural Element ◽  
The Impact

PurposeNatural ventilation is an environmentally friendly effective way of improving thermal comfort and the quality of indoor conditions if applied properly. This study aims to investigate the physical mechanism of the air movement and also the influence of building geometry in a cross-ventilated room through a parametric study of window geometrical characteristics using computational fluid dynamics.Design/methodology/approachMomentum and continuity equations are solved by the control volume method using a commercially available software. Standard k−ɛ turbulence model is employed to simulate the incompressible airflow and SIMPLE algorithm to solve the conservation equations. Mean air velocity magnitude is measured at three different surfaces of different heights, and the effect of incoming wind velocity inside the building is studied.FindingsThe research concluded that window hood and sill projections reduce indoor wind velocity magnitude, play a major role in incoming wind direction and thus have a crucial impact on wind circulation and indoor air quality.Social implicationsThe paper has evaluated redesigning of a both practical and ornamental architectural element named Palekaneh, which is found in many historical buildings in several hot places in the world. Its optimal design could increase indoor natural ventilation quality and decrease a space's cooling load. Therefore, a new passive cooling architectural element could be re-introduced to the regions previously enjoying such ornaments. This is economically efficient because it eventually saves a considerable amount of energy in the long run and is socially important because of the revitalization of architectural identity.Originality/valueThe role of a building envelope's physical features, although being studied for solar absorption and daylight availability, has rarely been investigated for natural ventilation, especially in a small scale, thus making the paper novel in this regard. This provides a guideline for designers to assess the impact of their design on redirecting wind-induced natural ventilation the very early stages of design.

scholarly journals Application of Wind as a Renewable Energy Source for Passive Cooling through Windcatchers Integrated with Wing Walls

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2536 ◽  
Author(s):  
Payam Nejat ◽  
Fatemeh Jomehzadeh ◽  
Hasanen Hussen ◽  
John Calautit ◽  
Muhd Abd Majid
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Passive Cooling ◽  
Quality Factors ◽  
Ventilation Performance ◽  
Wing Walls ◽  
The Impact ◽  
Ventilation Systems

Generally, two-third of a building’s energy is consumed by heating, ventilation and air-conditioning systems. One green alternative for conventional air conditioner systems is the implementation of passive cooling. Wing walls and windcatchers are two prominent passive cooling techniques which use wind as a renewable resource for cooling. However, in low wind speed regions and climates, the utilization of natural ventilation systems is accompanied by serious uncertainties. The performance of ventilation systems can be potentially enhanced by integrating windcatchers with wing walls. Since previous studies have not considered this integration, in the first part of this research the effect of this integration on the ventilation performance was assessed and the optimum angle was revealed. However, there is still gap of this combination; thus, in the second part, the impact of wing wall length on the indoor air quality factors was evaluated. This research implemented a Computational Fluid Dynamics (CFD) method to address the gap. The CFD simulation was successfully validated with experimental data from wind tunnel tests related to the previous part. Ten different lengths from 10 cm to 100 cm were analyzed and it was found that the increase in wing wall length leads to a gradual reduction in ventilation performance. Hence, the length does not have a considerable influence on the indoor air quality factors. However, the best performance was seen in 10 cm, that could provide 0.8 m/s for supply air velocity, 790 L/s for air flow rate, 39.5 1/h for air change rate, 107 s for mean age of air and 92% for air change effectiveness.

Numerical Analysis on the Impact of Windows and Interior Doors on Indoor Airflow of Rural Residence

2014 ◽  
Vol 548-549 ◽  
pp. 1683-1688
Author(s):  
Xiu Zhang Fu ◽  
Jian Dong
Keyword(s):  
Indoor Air ◽  
Natural Ventilation ◽  
Residential Building ◽  
Indoor Airflow ◽  
Average Wind ◽  
Ventilation Efficiency ◽  
The Mean ◽  
Simulation Results ◽  
The Impact ◽  
Average Wind Velocity

There are several factors impacting on the indoor airflows, such as building openings, ambient wind speed, occupants’ behavior and so forth. This paper concentrates on the impact of windows and interior doors on airflows in a rural multi-storey residential building. The indoor airflow simulation was carried out by using the CFD software. 3 states of interior doors were set, and 60 regions were arrayed in bedroom to observe the variation of airflows. According to data of regions, the uniformity of airflow and the thermal comfort were analyzed. Simulation results identified that closing interior doors will increase the mean age of indoor air about 7 times as it under the condition of opening doors, which is from 90s to 666s. It also shows that transom windows is beneficial to improve natural ventilation efficiency, as it can raise the average wind velocity by 40% when interior doors are closed.

The Analysis of the Impact of the Louver on the Natural Ventilation

2011 ◽  
Vol 243-249 ◽  
pp. 6997-7000
Author(s):  
Yi Wang ◽  
Pan Lu ◽  
Hai Bing Yao ◽  
Jia Ping Liu ◽  
Lu Lu Chen
Keyword(s):  
Velocity Profile ◽  
Pressure Distribution ◽  
Wind Velocity ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Model Building ◽  
Ventilation Rate ◽  
Air Distribution ◽  
Discharge Coefficients ◽  
The Impact

The louver affects natural ventilation rate and indoor air distribution. In this paper, the wind velocity profile and pressure distribution in the natural ventilation model building were simulated through CFD. And how different rotation angles of the shutter and different incidence angles of the wind affect natural ventilation rate were studied. Then, the influences of shutters on the discharge coefficients were analyzed, and use principles of the louver equipped in the building were proposed.

Sign in / Sign up

Export Citation Format

Share Document