In Quebec, we recently increased the capacity of bars, restaurants and theaters, and soon the mask will no longer be mandatory indoors.
These are places where exchange is possibleSays epidemiologist Nemo Machoff.
We would like to suggest ways to open it safely.
Nancy Delagrave, a physicist and scientific coordinator at Kovit-Stop, reminds us that if the vaccine is a key weapon in the fight against Govt-19, a variety of interventions are needed to combat the epidemic.
Ventilation is an inexpensive way to fight the virus. And it works, no matter the variation. If we had invested 1% of the energy in vaccinated on ventilation, we would be somewhere else …, Says the proponent of this pilot project.
At Byblos Cafe on Lourier Street in Montreal, with the summer heat, the windows are wide open. But owner Nina Javanmart agreed to install the CO2 sensor, knowing that the situation might be different in the fall.
I suspected that the air quality and circulation would be better if the windows were open. I can’t wait to see [la qualité de l’air] They will be closed this winter.
He adds that it is difficult to tell customers to wear the mask when they are not at the table. Measuring the air quality in her coffee gives her a little more control, says the owner.
Ms Javanmart believes that by measuring air quality, she can protect her employees and convince the government not to close everything if cases increase in the fall.
This would still be an argument, She says.
Small, easy-to-use devices
It must be remembered SARS-CoV-2 is spread primarily by air. Although it is not possible to accurately determine how many virus particles are present in a room or building, measuring CO2 levels is an indirect way to measure the risk of spreading a virus. Infected people excrete carbon dioxide and at the same time excrete virus particles. Therefore, the amount of CO2 represents the amount of virus particles in the air.
The sensors were designed by Andre Gorsen. Prior to the outbreak, this computer scientist sold sensors to farmers in the United States who wanted to measure CO2 levels to improve plant growth in their greenhouses.
Surprised this way
A little old-fashioned Used by the Quebec government to measure Air quality in schools This winter. For example, the actions taken by governments were done on a temporary basis and in a different way.
They don’t see trends. For many hours, many days they did not see the effect.
The sensors used in this pilot program measure CO2 levels every 15 minutes and the data is stored in a computer cloud.
Curves can be easily displayed on a tablet or business screen, and it is even possible to download data using the QR code. The sensors have a small light that turns red if the CO2 levels exceed the recommended standard.
This way, you can determine the quality of the air in a place just as you would the quality of food in a restaurant.
Ms Javanmart says the device is simple and seamless.
Every time I pass, I check to see if the light is green.
Somewhere else in the world
The Covid-Stop project was particularly inspired by Belgium, where restaurants, bars, gyms, swimming pools and shops were all required to install CO2 sensors and display the air quality in their building in public. If the sensors show a size of 900 to 1200 parts per million (ppm), owners should take action. If the fees are high, an inspector will be sent to the site. Penalties are expected for violating owners.
The United Kingdom advises traders to use this type of sensor, although without imposing it.
Japan used these devices long before the outbreak, especially due to significant air pollution. For example, some cinemas show CO2 rates at the entrances to rooms.
The team hopes to convince other businesses to install these sensors, which cost about $ 200.
Ms Machoff recalled that many restaurants and workplaces had to close due to the explosions, a blow to businesses already struggling to survive the epidemic.
This is a step towards making them more autonomous so that they can control their environment and provide a healthier environment.
What are acceptable CO2 standards?
The sensors allow traders to know the quality of the air their customers and employees breathe, says physicist Nancy Delagrave.
It is a visualization movement of transparency and risk.
But showing CO2 levels should be with education.
Most people do not know what it means and what are the safe limits, Explains Mrs. Delagrave.
Unfortunately, the instructions given to businesses and the messages sent to the public indicate that there is almost no air exchange and that you need to wash your hands. It is too late to understand all this, Reprimands Mrs. Delacroix.
Step ‘American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), When CO2 levels are high, people begin to feel some fatigue, headaches, and heat.
Everyone in the crowded conference room has experienced these symptoms. But we did not associate them with air quality, Explains civil engineer Manuel Kraft.
ASHRAE guides the design of systems to maintain 1000 ppm. The CSST sets the maximum limit at 5000 ppm for 8 hours.
Ms. Kraft believes these standards can be tightened when the virus is highly contagious in the community or if there are multiple outbreaks.
Ventilation rate should be adjusted according to the number of people in a room and function.
The transfer would be different if you had 30 teenagers expiring at the same time in a physical education class compared to a few people moving in an office, Says Ms. Kraft.
When we talk about respiratory viruses like Covit-19, Nancy Delagrave recalls, the highly contagious virus reduces CO2 levels to prevent it from spreading.
By delta variation, studies show that the viral load is 1000 times higher than the original strain. Therefore, it is better to target low fees.
For example, in a study of TB-affected schools in Taiwan, when CO2 levels were reduced from 3000 ppm to 600 ppm, cases were reduced by 97%.
Ms. Delagrave indicates that large explosions can be avoided, Similar to mega fitness in Quebec, By improving ventilation in enclosed spaces this fall.
CO2 sensors are one of the elements that can have a big impact in controlling explosions, Says Ms. Kraft.
What to do when CO2 levels are high?
There are many simple solutions, Kraft says.
Like us, buildings need to breathe. We need to bring them outside air, She says.
The first steps to take are opening the windows and starting the ventilation (e.g. bathroom extractors or kitchen hoods).
If these measures are not adequate, it is a sign of problems with the mechanical ventilation system of the building. A ventilation system consists of many components, and Kraft argues that only one of those pieces must be calibrated incorrectly or incorrectly in order for ventilation to be adequate.
According to this civil engineer, many businesses and buildings have dysfunctional or poorly repaired ventilation systems.
Data on air quality gives us an indicator and helps to point out the problem. It helps to manage risks and better control the situation.
Ms. Kroft believes she has known more about the issue of energy consumption than air quality in recent years. Epidemic has changed it.
Previously, ventilation was a necessary evil. Now people are starting to see if the air quality is good.
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