If you are managing buildings or facilities, you know that washing our hands and maintaining social distancing are important factors to reduce the spread of COVID-19. But equally important is the air we breathe inside buildings, and how well-circulated that air actually is.
Here’s what the experts have to say on good ventilation:
1. Avoid Stuffy Rooms
Research shows that there can be "airborne transmission" of the virus in confined spaces – as small virus particles linger in the air.
Pre-pandemic workplace regulations state that everyone should get 10 litres of fresh air every second, and that matters more than ever now.
So, if a room seems stuffy, you should just turn around and leave, says Dr. Hywel Davies, the 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."
2. Examine the Air Conditioning
Air conditioning is a welcome luxury on hot days - but the type of unit can be detrimental to proper ventilation.
The most common air conditioner is known as a split air conditioner – which functions by drawing in air from a room, chilling it and then blowing it back out. Essentially, it's only recirculating the air – risky if you’re indoors for several hours.
The EPA and CDC agree that “In general, the greater the number of people in an indoor environment, the greater the need for ventilation with outdoor air.”
3. Check Your Filters Regularly
Any modern ventilation system will have filters, but these are not without faults.
Researchers investigating the Oregon Health& Science University Hospital found that particles of coronavirus were trapped by the filters, but some had slipped through.
To minimise this, the WHO recommends to “Increase air filtration to as high as possible without significantly diminishing design airflow,” and “Inspect filter housing and racks to ensure appropriate filter fit and check for ways to minimize filter bypass.”
4. Determine the building’s “Fresh Air Ratio”
Given the current risk of coronavirus infection, the experts’ advice on managing building ventilation is to maximize the fresh supply.
From the BBC: "Having 100% outside air or close to 100% 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(though speaking in a personal capacity for this quote). "The more fresh air, the less you're running the risk of recirculating the virus through the building."
If you are a building manager it is your responsibility to ensure that fresh air is being piped in at a rate that minimizes the potential need for old air to be recirculated. However, the negative side to running 100% fresh air is the cost - the outdoor air has to be heated in winter which requires both energy and money.