A UNIVERSITY College Cork (UCC) professor has advised businesses of best practices in terms of ventilation of their premises when welcoming back customers.
Professor John Wenger of UCC’s School of Chemistry and Environmental Research Institute carried out an experiment with Nora Cronin of Head to Toe salon on Princes Street which involved leaving a CO2 monitor in the salon and testing the effects of cross ventilation on the salon’s air quality.
Speaking to The Echo, Prof Wenger said: “In a poorly ventilated area, the virus can build up just like cigarette smoke would build up, so ventilation clears the amount of virus and is a good way to reduce transmission.
“So as the reopening started last week, I was really excited to test what ventilation will be like in some typical scores, and my friend Nora Cronin who runs Head to Toe on Princes Street was willing to test out her ventilation for me.
“I gave her some basic advice about opening doors and windows. I lent her one of my carbon dioxide monitors, and these are very useful tools for assessing ventilation because what they do is measure carbon dioxide in the air, and CO2 is a good indicator of how fresh the air is inside a room because we all breathe it out.”
Prof Weger explained that outdoor levels of carbon dioxide are about 400ppm, meaning that in one million molecules of air, 400 are carbon dioxide molecules.
He said that in a typical classroom with windows and doors closed, the amount of carbon dioxide in the air can multiply to over 1,000ppm which affects concentration, learning ability, and cognitive performance.
To record the amount of carbon dioxide in Ms Cronin’s salon, she placed the monitor away from where customers would be sitting so as not to influence the reading with peoples’ breath. The monitor showed a reading of 800ppm with a window open and upon opening the door, carbon dioxide in the salon dropped to outdoor levels of fresh air.
“This shows the importance of having more than one window or door open so you have what we call cross ventilation so that the air can move through the room, you’ve got to have an in and out basically.
“Airflow really helped accelerate the flushing out of the virus. It’s a very simple demonstration and if people take that advice on board then they’re doing the best that they can to protect their customers,” Prof Wenger said.
He said that although carbon dioxide monitors can be an investment of about €200, that the payback is worth it for business owners who know they are “doing all they can for their staff and customers”.
“I think as we move forward people will be interested more and more in the quality of the air that they breathe. We spend 90% of our time indoors so we need to take care of the quality of our air.
“There are places around Europe, Japan and USA that are starting to do this now so you will see, for example, a CO2 reading on the door of a restaurant in San Francisco saying ‘we’ve got good ventilation’, so some people are aware of that now and as we move forward I think this might well be a more regular feature of our indoor activities,” he said.