As the entire nation is looking forward to going back to work, questions are being raised about the safety of people from Covid 19 when they are indoors. According to experts, people are the main source of contaminants in an indoor environment.
Ventilation, Air Filtration Play Key Role In Preventing Covid-19 Indoors
The chances of catching an infection in an indoor environment depend on the size of the room and the number of occupants who are infected in that room. Small respiratory aerosols are often released when people talk loudly or when they breathe heavily in an indoor environment. The aerosols can soon buildup in an indoor environment and put everyone at risk.
Experts compare this with the smoky bar and mention how it can become cloudy when too many people start smoking in the indoor environment. They say that even the virus is similar and it can build up over a period of time in an enclosed room.
In this regard, understanding the air quality terminology is essential for the safety of everyone so that they can ask the right questions about building safety towards Covid 19. The ventilation rate is the outside air volume that is available per unit of time. The Air change rate is the ventilation rate of the space divided by space volume. This can give an indication about how fast the room is able to clear the airborne contaminants.
The transmission risk is drastically reduced when you are able to clear the airborne virus quickly. As per current standards, most air conditioners and heating systems recirculate about 80 per cent of air and only supply 20% fresh air so that the energy is saved during the process.
The American Society of Heating, Refrigerating and Air Conditioning Engineers provide the air ventilation standard for various commercial buildings. This includes daycares, schools, woodshops and computer labs. The minimum ventilation rates vary depending on what type of activity is being conducted in the room. In this regard, a workshop has a higher recommendation than a regular classroom.
According to ASHRAE recommendation, a ventilation rate of 500 cubic feet per minute of outside air is needed for a 1000 square foot classroom that has 35 people. This includes both students and teachers. Due to the pandemic, the requirements have doubled, and the institutions have to either alter the buildings or settle with less number of occupants per room to meet the new recommendations.
Social distancing becomes crucial in enclosed rooms, and limiting the number of people in a closed environment is the best way to reduce the risk of transmission in the long run. In this way, even if an infected person is present in the room, the virus may not reach other people when sufficient distance is maintained and when the room has decent ventilation.
Just by reducing the number of occupants in a room by 50%, it is possible to supply double the amount of outside air per person, and this reduces the transmission of airborne diseases by a huge margin.
Apart from that, using masks will also help to reduce the risk of infection, and it will block the virus in the mask itself in most cases and not allow it to get easily into the outside environment.
Some other changes that may be necessary are opening the windows whenever possible as this allows outside fresh air and keeps the air circulation intact. In this case, even if the virus is present in the room, it gets diluted by a huge margin due to the free flow of air across the room.
In the same manner, changes have to be made to the way fans are positioned in the room. The fans should not be blowing air around the room as this can spread the virus around the room, and they should instead be throwing air outside the room. Blowing air inside out is the best way to remove virus in the room, and this can suck fresh air in a natural way into the room.
Air filters may also become the norm in the near future as this can improve the air quality when you are using air conditioners or heaters. The recirculated air has to be filtered appropriately to avoid the risk of spreading the virus. The authorities of the building have to use HVAC filters to improve the air quality in closed rooms.
Using GErmicidal UV light is also a good option, and it can be used in many ways. One of the easiest ways is to use the fixtures that emit such light, and this can be beamed overhead across the room.
This can reduce the chances of virus transmission by a huge margin. In the same way, the UVC light can be used in recirculating the air duct, and this will kill the virus in the filtration process.
Many such things are needed to counter the virus in the near future till a trusted vaccine is ready in the market. Considering the latest developments in this regard, experts are of the opinion that getting a vaccine for every person at work or school may take another year and we have to take care of social distancing norms and other safety factors till then in a serious way.
Most classrooms and buildings will now have less number of occupants than before, and they will have to work on proper air circulation systems. Till now, not many people bothered about air circulation and other aspects and only worried about heating or cooling the building.
However, it has now become important to ensure proper air circulation in an indoor environment as even one single infected person staying in the room for long hours can spread enough virus across the room. In this way, it puts every other occupant at risk when proper air circulation is not ensured in the indoor environment.
The best thing that building owners can do is to use as many windows as possible so that the natural air gets circulated freely across the room and this can also reduce the energy expenditure of the building by a huge margin.