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Biocontaminants 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.

This 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.

According 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.

The 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.

Poor indoor air quality (IAQ) contributing to occupants’ health symptoms is a universal, typically ventilation-related, problem in schools. In cold climates, low-cost strategies to improve IAQ in a naturally ventilated school are rare since conventional methods, such as window opening, are often inappropriate. This paper aims to present an investigation of strategies to relieve health symptoms among school occupants in naturally ventilated school in Finland.

A case study approach is adopted to thoroughly investigate the process of generating the alternatives of ventilation redesign in a naturally ventilated school where there have been complaints of health symptoms. First, the potential sources of the occupants’ symptoms are identified. Then, the strategies aiming to reduce the symptoms are compared and evaluated.

In a naturally ventilated school, health symptoms that are significantly caused by insufficient ventilation can be potentially reduced by implementing a supply and exhaust ventilation system. Alternatively, it is possible to retain the natural ventilation with reduced number of occupants. The selected strategy would depend considerably on the desired number of users, the budget and the possibilities to combine the redesign of ventilation with other refurbishment actions. Furthermore, the risk of poorer indoor air caused by the refurbishment actions must also be addressed and considered.

This study may assist municipal authorities and school directors in decisions concerning improvement of classroom IAQ and elimination of building-related symptoms. This research provides economic aspects of alternative strategies and points out the risks related to major refurbishment actions.

Since this study presents a set of features related to indoor air that contribute to occupants’ health as well as matters to be considered when aiming to decrease occupants’ symptoms, it may be of assistance to municipal authorities and practitioners in providing a healthier indoor environment for pupils and teachers.

Natural 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.

Momentum 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.

The 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.

The 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.

The 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.

Poor indoor air quality in schools is a worldwide challenge that poses health risks to pupils and teachers. A possible response to this problem is to modify ventilation. Therefore, the purpose of this paper is to pilot a process of generating alternatives for ventilation redesign, in an early project phase, for a school to be refurbished. Here, severe problems in indoor air quality have been found in the school.

Ventilation redesign is investigated in a case study of a school, in which four alternative ventilation strategies are generated and evaluated. The analysis is mainly based on the data gathered from project meetings, site visits and the documents provided by ventilation and condition assessment consultants.

Four potential strategies to redesign ventilation in the case school are provided for decision-making in refurbishment in the early project phase. Moreover, the research presents several features to be considered when planning the ventilation strategy of an existing school, including the risk of alterations in air pressure through structures; the target number of pupils in classrooms; implementing and operating costs; and the size of the space that ventilation equipment requires.

As this study focusses on the early project phase, it provides viewpoints to assist decision-making, but the final decision requires still more accurate calculations and simulations.

This study demonstrates the decision-making process of ventilation redesign of a school with indoor air problems and provides a set of features to be considered. Hence, it may be beneficial for building owners and municipal authorities who are engaged in planning a refurbishment of an existing building.

The use of natural ventilation by large openings to maintain thermal comfort conditions in the premises is a concept that is perfectly integrated into the traditional architecture of countries in the Mediterranean region or in tropical climates. In a temperate climate where the architecture is not usually designed to respond to the use of natural ventilation is seasonal and is done at the initiative of the occupants by making changes in the design of their doors. The European interest in natural ventilation, as a passive building air-conditioning technology, is increasing and has been the subject of a research program commissioned by the European Community. In this work, the authors consider a part of a housing compound as a refreshing floor. This floor is maintained at a constant cold temperature, the one vertical wall at hot temperature and other surfaces are adiabatic. Various scenarios are considered for this work. Mixed convection for different boundary conditions and different configurations is carried out. In addition, an airflow is injected through a window and extracted on the opposite window. Classical conclusion and transitional value on Richardson number have been completed by the new thermal configuration with nonsymmetric thermal conditions. The complex 3D flow structure is more obvious when one of the two flows (ventilation or natural convection) dominates. However, the induced heat transfer is less sensitive to the added ventilation. In this study, the authors consider a part of a housing compound as a refreshing floor. This floor is maintained at a constant cold temperature, the one vertical wall at hot temperature and other surfaces are adiabatic.

This is a qualitative preliminary study of a 2D–3D flow. The authors examine the competition between the natural convective flow and the added airflow on the flow structure and indoor air quality. The numerical model shows a good agreement with that obtained by researchers analytically and experimentally. To deal with turbulence, the RNG k-ε model has been adopted in this study.

The transfer is more sensitive between the 2D and 3D cases for the present analyzed case.

The study of ventilation efficiency has shown the competition between the big and small structures and the induced discomfort.

Achieving an appropriate indoor environment quality (IEQ) is crucial to a green office environment. Whilst much research has been carried out across the globe on the ideal IEQ for green offices, little is known about which indoor environment New Zealand office workers prefer and regard as most appropriate. This study investigated New Zealand office workers' preference for a green environment.

Workers were conveniently selected for a questionnaire survey study from two major cities in the country – Wellington and Auckland. The perception of 149 workers was analysed and discussed based on the workers' demographics. The responses to each question were analysed based on the mean, standard deviation, frequency of responses and difference in opinion.

The results showed that workers' preferences for an ideal IEQ in green work environments depend largely on demographics. New Zealand office workers prefer work environments to have more fresh air and rely on mixed-mode ventilation and lighting systems. Also New Zealand office workers like to have better acoustic quality with less distraction and background noise. Regarding temperature, workers prefer workspaces to be neither cooler nor warmer. Unique to New Zealand workers, the workers prefer to have some (not complete) individual control over the IEQ in offices.

This study was conducted in the summer season, which could have impacted the responses received. Also the sample size was limited to two major cities in the country. Further studies should be conducted in other regions and during different seasons.

This study provides the opportunity for more studies in this area of research and highlights significant findings worthy of critical investigations. The results of this study benefit various stakeholders, such as facilities managers and workplace designers, and support proactive response approaches to achieving building occupants' preferences for an ideal work environment.

This study is the first research in New Zealand to explore worker preferences of IEQ that is not limited to a particular building, expanding the body of knowledge on workers' perception of the ideal work environment in the country.

The purpose of this paper is to investigate a wall-integrated solar chimney for passive ventilation of a building cavity. Ventilation is required to improve the circulation of air in the built environment. This can be achieved through natural or forced convection. Natural circulation can be driven by renewable energy, and so it promotes sustainable exploitation of energy resources. Solar energy is one of the promising renewable energy resources.

The chimney was designed to face the Equator on the wall of a room which required ventilation. Mean monthly daily heating and cooling loads of the room were computed with and without a solar chimney by using hourly meteorological data from nine different weather sites at low, medium and high latitudes. The chimney was implemented with and without airflow control, and simulated by using the ESP-r software.

Results show that the solar chimney with airflow control marginally reduced the heating load in the building envelope, with a similar effect being exhibited by the chimney with uncontrolled airflow. The cooling load was reduced by the controlled airflow at all the nine sites. In contrast, the uncontrolled airflow increased the cooling load at some sites. In addition, the chimney with airflow control reduced the annual total thermal load at all the sites, while the chimney with uncontrolled airflow raised the total thermal load at some locations.

The performance of solar chimneys designed with and without airflow control systems has been investigated under the same prevailing meteorological conditions at a given site. Findings show that controlling airflow in a solar chimney reduces the total thermal load in the built environment. This information can be applied in different parts of the world.

Energy efficient building design strategies are growing in popularity, promoted through increased awareness of climate change, rising energy prices, global consciousness and a demand for energy security. To aid this design process, assessment tools such as Code for Sustainable Homes (CSHs) and Passivhaus were introduced in the UK. However, it is suggested that these tools prioritise energy efficiency over occupant health through a fundamental lack of attention to indoor air quality (IAQ). The purpose of this paper is to investigate IAQ in selected dwellings built using CSHs level 6, level 3 and Passivhaus homes in the UK.

Using a case study approach, the investigation consisted of IAQ measurements during summer and winter months, occupant diaries and occupant interviews.

The results from the IAQ measurements show the recommended maximum level of 1,000 ppm was breached in all three Code 6 and two Code 3 homes, with levels slightly below this limit in the two Passivhaus homes. Measurements found high levels of formaldehyde, carbon dioxide and low levels of relative humidity.

There is a need for the adequate consideration of IAQ in sustainable assessment methods, including the use of mandatory credits to ensure occupant health is not disregarded in the drive towards zero carbon.

These results can be used to recognise areas of improvement in the CSHs and Passivhaus standard, and the design of energy efficient homes in general. Research of this nature is essential to ensure occupant health is not sacrificed through the drive towards zero carbon.

With the problem of environment and energy becoming prominent, energy conservation and emission reduction have received more attention. In the using process, buildings not only have the inherent energy consumption but also have the energy consumption of equipment that is installed for improving the indoor environment. This study aims to investigate how to reduce the energy consumption of buildings through utilizing natural resources.

This paper briefly introduces three objective functions in the building energy-saving model: building energy consumption, natural lighting and natural ventilation. Genetic algorithm was used to optimize the building parameters to achieve energy conservation and comfort improvement. Then a two-story rental building was analyzed.

The genetic algorithm converged to Pareto optimal solution set after 10,000 times of iterations, which took 61024 s. The lowest energy consumption of the scheme that was selected from the 70 optimal solutions was 5580 W/(m²K), the lighting coefficient was 5.56% and Pressure Difference Pascal Hours (PDPH) was 6453 h; compared with the initial building parameters, the building energy consumption reduced by 3.40%, the lighting coefficient increased by 11.65% and PDPH increased by 9.54%.

In short, the genetic algorithm can effectively optimize the energy-saving parameters of buildings.

The purpose of this study is to conduct a rigorous systematic literature review and present a summary of building systems and technologies that can be used to mitigate the spread of airborne viruses. With the recent outbreak of COVID-19, occupants’ health and indoor air quality (IAQ) have become a critical issue for facility managers to maintain the full functionality of the buildings. An improved understanding of these available systems will help facility managers and building owners to protect the health and safety of building occupants.

The PRISMA protocol was used for defining the literature search methodology. The concept mapping technique was used for determining the keywords. The keywords were then used to search for relevant articles using the Scopus database and Google Scholar. A thorough bibliometric analysis and qualitative analysis were conducted for the selected publications.

It was found that sensor technologies, botanical air-filtration systems and artificial intelligence could be used to effectively monitor and improve IAQ. In addition, natural ventilation is one of the low-cost and effective methods of reducing contaminants from the indoor air. Computational fluid dynamic modeling can be used to understand the flow of virus particles within the building through the heating, ventilation and air-conditioning (HVAC) system. Several changes to the HVAC system are also discussed.

This study contains a diversity of methods from the existing literature that were systematically selected to present the state-of-the-art building systems and technologies that can effectively improve IAQ. The researchers plan to follow up on the findings of this research and will conduct an empirical study to assess its impact on IAQ.