Re-learning the importance and possibility of natural air ventilation during Covid

‘The Penang Hospital began life as a double-storey, colonnaded brick-and-timbre building. As was the norm for most bungalows in Penang at the time, the building would have been raised on a brick plinth, allowing for air to flow underneath. The floors were probably hardy and washable, and tiled with terra cotta. The veranda on the first-floor was 5ft wide and protected by a roof jack, a feature developed by builder designers of the day in observance of tropical architecture.

“A roof jack,” explains conservation architect Laurence Loh, “is a secondary roof located at the ridge that is literally jacked up for the hot air within the space to rise up and escape through the open gaps between the two roofs, based on the principle that air, once warmed, becomes more buoyant, with a tendency to rise.” This process employs what is known as stack effect or ventilation. The surrounding cool air is pulled into the building from openings like doors and windows at the lower level, with the heated air being pushed up and out.’

But how has it evolved?

Read here (Penang Monthly, October, 2021)

The role of built environments in preventing contamination and reducing the spread of Covid-19 for future pandemics

‘The built environment contributes to the spread and contamination of the virus, as people spend more than 90% of their time indoors and even more during lockdown and community quarantine. During the current pandemic, healthy and asymptotic individuals are staying in their houses, and many people that are affected by the virus are now in hospitals and in healthcare facilities. These situations might affect the spread and contamination of the virus, as well as individuals’ interactions with each other.

‘To reduce the contamination and spread of the virus in the built environment that might affect healthy individuals – such as health care professionals, office workers – it is important to understand the steps that need to be taken and the policies to be implemented along with the theories underlying them. One of the approaches to be considered in designing effective fresh air supply and air extraction ventilation systems to minimize the concentration of suspended viruses. This is in addition to other essential procedures to understand the movement of viruses in the indoor air and its suspension/resuspension to and from surfaces.’

• Is it safe to reopen theaters during the Covid-19 pandemic?
• What’s in the pipeline? Evidence on the transmission of SARS-CoV-2 via building wastewater plumbing systems
• Ventilation for residential buildings: Critical assessment of standard requirements in the Covid-19 pandemic context
• Ventilation system design and the coronavirus (Covid-19)
• Outdoor airborne transmission of coronavirus among apartments in high-density cities

Read here (Frontiers in Built Environment, as at September 12, 2021)

Ventilation for residential buildings: Critical assessment of standard requirements in the Covid-19 pandemic context

‘After the arrival of a new airborne virus to the world, science is aiming to develop solutions to withstand the spread and contagion of SARS-CoV-2. The most severe among the adopted measures is to remain in home isolation for a significant number of hours per day, to avoid the spreading of the infection in an uncontrolled way through public spaces. Recent literature showed that the primary route of transmission is via aerosols, especially produced in poorly ventilated inner spaces. Spain has reached very high levels concerning contagion rates, accumulated incidence, or number of hospitalizations due to COVID-19. Therefore, this article aims to develop a quantitative and qualitative analysis of the requirements established in Spain, with respect to the European framework in reference to ventilation parameters indoors. The different parameters that serve as calculation for the ventilation flow in homes are analyzed to this aim. Results show that the criteria established in the applicable regulations are insufficient to ensure health and avoid contagion by aerosols indoors.’

Read here (Frontiers in Built Environment, August 24, 2021)

Ventilation system design and the coronavirus (Covid-19)

‘Most new office buildings in Nordic countries are equipped with balanced mechanical ventilation systems. The purpose of ventilation in office buildings is to provide thermal control by supplying cold or warm air for adequate indoor air quality. However, the role of ventilation in preventing virus transmission and maintaining a sufficient fresh air supply to obtain a low virus level through dilution is not currently well defined. Ventilation in office buildings is expected to contribute to preventing the spread of contaminants and provide comfort for occupants. The study reveals differences between risk areas for spreading airborne contaminants in office buildings in northern Europe, including Denmark, Norway and Sweden. The differences in the spread depends on different ventilation designs used in different countries.’

Read here (Frontiers in Built Environment, April 27, 2021)