Where to sit to avoid getting COVID 19?
Where to sit to avoid getting COVID 19, according to scientists is at the back of a well-ventilated air-conditioned free room.
However, it’s not just a matter of walking into any room and taking the back seat without taking into consideration the precautionary measures put in place.
Accordingly, one should note that it doesn’t take long for airborne coronavirus particles to make their way through a room, with people sitting near an infected person being at a higher risk of getting infected.
However, the longer the infected person stays in the room, the more everyone in the room is like to get infected as the tiny aerosols spread in the air.
In an experiment meant to track how aerosols move, including those in the size range that can carry viruses, the scientists discovered the highest-risk areas in rooms and why proper ventilation is crucial.
The experiment which only proves what we already know – more distance less risk of infection, also confirms that ventilation is important in a crowded room with an infected person.
With current models describing the role of ventilation on the fate of airborne microbes in a room assume the air is well mixed, with the particle concentration uniform throughout.
While a poorly ventilated room or small space makes the entire room is a high-risk region, larger spaces, such as classrooms with good ventilation reduces risk since the level of risk depends a lot on ventilation.
The scientists experiment on how to risk a room is by doing this;
- They used a 30-foot by 26-foot university classroom designed to accommodate 30 students that had a ventilation system that met the recommended standards.
- They injected aerosol particles similar in size to those from humans into a room and then monitored them with sensors.
- Within 10 to 15 minutes, the particles that had been released at the front of the classroom had reached the back of the room
The scientist discovered something new;
- With active ventilation in the room, the concentration at the back is less.
- 20 feet from the source, has only one-tenth of the realized particles.
- Appropriate ventilation limits the risk of getting COVID-19 to the people near the infected person.
- 30 minutes are enough to have 95% of particles dissolved in a properly functioning ventilated room.
- However, as more time is spent with an infected person, the risk of infections extends to the entire room despite having appropriate ventilation.
- The corners of the room hold the particles longer than anywhere in the room.
- Being close to an air exit vent means you as a magnet to the particles
- Keeping windows open increases the air exchange rate.
To minimize COVID-19 transmission in any room, it is recommended that you isolate the infected person in addition to implementing engineering measures such as ventilation, partition shields and filtration units which directly remove particles from the air.
While all these are recommended, any room with proper ventilation is the most effective tool to minimize the spread of the infection.
Facts about ventilation
According to science air exchange of one per hour means that the air supplied to the room over one hour equals the volume of air in the room.
Thus the air exchange rate varies with homes having less than one while hospitals have around 15-25 in operating rooms.
In the classroom, according to current regulations of primary airflow correspond to an air exchange of about six per hour, this translates to for every 10 minutes, the amount of air brought into the room equals that of the volume of the room.
Thus the level of concentration depends in part on the number of people in the room, how much they emit and the air exchange rate.
The fact that students are social distancing thereby reducing classroom populations by half and everyone wearing masks, the air in many classrooms is cleaner now than it was before the pandemic.