Indoor air quality must be treated to prevent the spread of the virus – AirQualityNews
Andy Makin, Managing Director of EnviroVent, examines the problem of poor ventilation in homes and how we can fail a generation by not dealing with it properly.
In the 1800s, the public rose up against the lack of sanitation and contaminated water in British cities, causing epidemics, disease and death.
Sanitation surveys have shown that there is a relationship between disease and dirt in the environment, and it was widely believed that safeguarding public health is “the job of the engineer rather than the doctor” .
As a result, the Public Health Act of 1848 established a General Health Council to help local authorities improve sanitation. Over the following decades, the introduction of good sanitation became a priority, and as a result, illnesses and deaths from associated illnesses, such as dysentery, were reduced and ultimately eliminated.
Fast track through 2021 and experts say current ventilation rules fail to stop infections, including Covid-19, which are spread among the population through shared use of buildings and homes. Evidence shows that Covid-19 is often transmitted by infectious air particles in crowded indoor spaces.
In the review Science, scientists and engineers point out that while governments have regulations on food safety, sanitation and drinking water, there are far fewer regulations when it comes to pathogens in the air.
Professor Cath Noakes, environmental engineer at Leeds University, said: “Air quality is invisible to us, we ignore it, but it affects us day in and day out, carrying respiratory diseases that affect the air. likelihood of people getting infections …… the spread of infection has generally not been a priority in building design. ‘
Some experts believe that a revolution is needed in the way governments regulate indoor air quality and how the issue is taught to the next generation of ventilation and air conditioning apprentices.
The latest government guidelines on limiting the spread of the virus are that indoor environments should be ventilated as much as possible to reduce the risk of transmission by diluting indoor air with fresh outdoor air. The guidelines state that exhaust fans with exterior vents should be used or that windows should be opened to allow natural ventilation.
Mechanical ventilation was found to be much more efficient than natural ventilation in a recent study by EnviroVent’s parent company, S&P UK, titled The Importance of Good Ventilation (Before, During and After a Global Pandemic): Model airborne transmission risk analysis.
The study aimed to answer the question of whether natural ventilation – opening windows – is sufficient to mitigate the risk of Covid-19 infection or whether a mechanical ventilation system is necessary. The study looked at three different cases: a classroom, a bar and an office.
He revealed that the risk of transmitting Covid is halved when using mechanical ventilation compared to opening windows to create natural ventilation.
In addition, the study points out that opening windows as a means of ventilation is unrealistic in many cases, as this can cause safety concerns and introduce unfiltered and potentially polluted air from the outside. in the House.
Research shows that natural ventilation can vary widely from 0 to over 10 ACH (air changes per hour) under specific conditions. Therefore, mechanical ventilation allows a building owner to set ventilation rates precisely in accordance with the requirements of UK standards.
Interestingly, in the classroom study, the research showed that mechanical ventilation delivering standard flow rates was able to remove most of the viral concentration during a break from play (30 minutes) and completely remove infectious particles for the two-hour lunch break. By comparison, in a natural ventilation scenario, the open windows were not able to completely remove the virus concentration during any of the breaks.
The results show the importance of adequate ventilation and reinforce the benefits of mechanical ventilation systems. In particular, mechanical ventilation allows higher ventilation rates than natural ventilation (in the vast majority of cases), which leads to a lower risk of infection.
Although the study looked at classrooms and commercial locations, it demonstrates the advantages of mechanical ventilation in reducing and eliminating the risk of transmission in all situations, compared to natural ventilation.
Through the BEAMA Ventilation Group, we are preparing ourselves as an industry to meet the current and future needs of the public who will be responsible for ensuring that their homes have sufficient ventilation to protect occupants from disease and health problems.
While some members of the public have recognized the health benefits of incorporating mechanical ventilation for problems such as condensation and mold growth in their homes, which can exacerbate health problems, such as asthma , we need to be more aware.
One solution is Whole House Positive Entry Ventilation (PIV) systems, which can easily be retrofitted into homes or apartments.
They provide fresh filtered air into the house to ventilate the entire property. This method dilutes, displaces and replaces high humidity levels, which not only controls condensation but also improves indoor air quality. PIV is most commonly installed in renovated and modernized properties and a compliant and good quality installation is essential.
It is possible to foresee a time in the future when air quality will be as important as ensuring good water quality in a building. In the meantime, it is good practice for the government to focus its efforts on improving the quality of indoor air in buildings, in order to meet the current and future health needs of the public.
Photo by Li Lin