We’ve been told to stay at homes and not come out without urgent needs during the Covid-19 pandemic to keep ourselves safe. But we are not totally safe from the virus at home.
For months people were told to wash hands and maintain social distance to fight against coronavirus but scientists and engineers say there is a need to think about the air we are breathing, as countries around the world start gradually opening up educational institutions and offices.
Health experts say good ventilation could be the key to avoiding coronavirus as people spend more time indoors.Good ventilation matters in five ways, reports BBC.
If it’s stuffy, walk away
When you walk into a room and the air feels stale, then something is wrong with the ventilation. Not enough fresh air is being introduced, which increases chances of getting infected by coronavirus.
Recent research shows that in confined spaces there can be “airborne transmission” of the virus – with tiny virus particles lingering in the air.
According to workplace regulations set up before the pandemic, everyone should get 10 litres of fresh air every second, and that matters more than ever now.
So if a place seems stuffy, just turn around and leave, says Dr Hywel Davies, technical director of the Chartered Institution of Building Services Engineers.
“If you’ve got someone who’s infected in a building, and you’re bringing in plenty of outside air, you’re diluting whatever infectious material they’re giving off. You’re reducing the risk of other people becoming infected,” he said.
Look up at the air conditioning
The simplest air conditioner is a slender white box mounted on walls or ceilings, known as a split air conditioner.This draws in air from a room, chills it and then blows it back out again. In other words, it’s recirculating the air.
This is no problem for a quick visit but may be a risk over a period of hours.A study of a restaurant in China blamed this type of air conditioner for spreading the virus.
Dr Davies points again to the importance of fresh air: “If there had been a good supply of outside air, very likely fewer people would have become infected – if any.”
Ask about the ‘fresh air ratio’
In a modern building where the windows are sealed, how can you get enough fresh air?You’re relying on a ventilation system in which stale air is extracted from the rooms and piped to an air handling unit, often on the roof.
There, fresh air can be pulled in from outside and mixed with the old inside air, before being sent back into the building.
Given the risk of coronavirus infection, the professional advice is to maximise the fresh supply.”Having 100 percent outside air or close to 100 percent is a good thing,” says Prof Cath Noakes of the University of Leeds and chair of the environmental panel of the government’s SAGE advisers, speaking in a personal capacity.”The more fresh air, the less you’re running the risk of recirculating the virus through the building.”
Check if there’s virus in the filters
A modern ventilation system will have filters but these are not fool-proof.In the US, researchers investigating the Oregon Health & Science University Hospital found that traces of coronavirus were trapped by the filters but some had somehow slipped through.
Prof Kevin van den Wymelenberg, who led the project, believes that swabbing the filters could reveal if there’s someone infected working in a building.
In South Korea, a call centre on the 11th floor of an office building saw one person infect more than 90 others. If the filters had been checked more frequently, the presence of the virus might have been spotted sooner.
Watch out for draughts
Talk to any expert in the field and they will say that fresh air is the key.But one specialist in modelling the movement of air says it’s not that simple.
Nick Wirth used to design Formula 1 racing cars, and now advises supermarkets and food-processing companies on how to manage air flow to keep people safe.
He worries that if someone sitting beside an open window turns out to be infectious, they could shed virus to others downwind.
“If you open a window, where is the air going to go?” he asks. “We don’t want people in a direct line of that airflow.
“More fresh air in general is better but if it’s flowing horizontally and full of virus it could have unintended consequences.”
Prof Cath Noakes says the benefits of plentiful fresh air diluting the virus will outweigh any risks.An open window might lead to more people receiving the virus but in smaller, less risky amounts, in her view.
source: UNB
