From The University of Toronto (CA) : “‘A really big deal’ U of T’s Colin Furness on why ventilation is key to fighting COVID-19”

From The University of Toronto (CA)

November 24, 2021
Mariam Matti

Photo by Steve Russell/Toronto Star via Getty Images.

As the weather turns colder and people move indoors, the University of Toronto’s Colin Furness is emphasizing the importance of proper ventilation to combat the spread of the virus that causes COVID-19.

The expert in infection control epidemiology and COVID-19 pandemic management says it’s well-established in the medical community that airborne transmission is major contributor to the spread SARS‑CoV‑2. But he notes that public health regulations have often been slow to catch up, leaving many businesses and other organizations with less-than-optimal safeguards.

There is, however, a notable exception: post-secondary institutions.

Furness recently spoke to University Affairs about how some universities – including U of T – are at the forefront of addressing ventilation by retrofitting HVAC systems.

At U of T for example, HVAC experts made recommendations that were quickly adopted. Centralized HVAC system filters that service all parts of buildings including offices, meeting rooms and hallways, were replaced with enhanced MERV 13 filters (or the highest compatible with the existing HVAC infrastructure). Demand-control ventilation measures (typically in place to support energy conservation efforts) were disabled to maintain consistent in-air flow. Ventilation systems are turned on two hours before occupancy every morning to replace the air in entire buildings, a process known as flushing.

“Universities have expertise. They’ve got respect for expertise. And they have decision-making that actually incorporates that expertise,” says Furness, an assistant professor, teaching stream, in the Faculty of Information with a cross-appointment to the Institute of Health Policy, Management and Evaluation at the Dalla Lana School of Public Health.

He adds that such qualities make universities “incredibly resilient.”

Furness has even gone so far as to test the air quality in his own classroom.

To learn more about why HVAC systems matter, U of T News spoke with Furness about airborne transmission of SARS‑CoV‑2 and how to guard against it.

Why is having proper ventilation so important in combatting COVID-19?

In the earliest days of the pandemic, we relied on our existing knowledge around transmission. It was a model that said large droplets are it and therefore we don’t need to worry about air – but that view was flawed. It allowed us to explain a communicable respiratory disease, even though it wasn’t quite correct.

We now know that not only does COVID-19 move through the air, but that air seems to be the dominant mode of transmission. That’s a very new way of thinking. It means we have to unlearn a lot about what we thought we knew about respiratory disease. We’ve learned more about respiratory disease transmission in the last year and a half than I think we ever have. It’s a really big deal.

It seems like universities adapted fairly quickly, compared to other organizations. Why do you think that is?

Universities have expertise. They’ve got respect for expertise. And they have decision-making that actually incorporates that expertise. Those are three things that make universities incredibly resilient.

We didn’t wait for others to say air matters. The leading voices in Canada are here at the U of T with respect to infectious disease and epidemiology. We consulted our own internal expertise.

U of T jumped in from the beginning and started prioritizing air and ventilation, which is really smart.

Can you explain why proper HVAC systems are effective in combating the virus?

What we understand with airborne transmission is that, if you’re infected and you exhale, the virions of the virus – viral particles – are going to stay in the air for a long time and they’re going to accumulate in the air. In other words, an infected person sitting in a room is going to continue to add to the concentration of dangerous virions in the room.

What ventilation does is it take those virions and flush them out of the room by changing the air.

You can have two people in a very well-ventilated room – one sick, one not, and the person who’s not sick is perhaps not going to get sick because they’re not breathing in the unadulterated exhalations of the other person. They’re also breathing in fresh air.

Can you talk about what you’ve found testing the air quality in your classroom?

I work in a building that has forced air circulation. It has mechanical systems that can be adjusted to do what they do best. They not only circulate air, but they also exchange air from the inside the room with the air from outside the building.

In my classroom, I’ve measured the CO2 levels. The more carbon dioxide there is in the room, the more exhalations you have as opposed to fresh air. Outdoor air is about 400 parts per million in carbon dioxide. That’s the gold standard. If you’ve got air that is higher than 1,500 parts per million, you’ve got stale air.

With COVID-19, the best practice says you should try and stay under 800 parts per million, which is very aggressive. I found my classroom is usually around 460 to 520 – so very, very close to outdoor air. I’ve got 25 students in this class and the room is big and the other thing is, at the moment, the building is sparsely populated. So, as more people start to spend more time there, we might expect those numbers to creep up a little bit. But I was flabbergasted. I bought a second unit because I didn’t think the air could be that good.

I want to point out that I’m lucky. There are many buildings that don’t have forced air where managing air quality is going to be a lot harder. And you’ve got other kinds of challenging places like university residences and labs that have people working in close proximity and pretty complicated infrastructure. I mean, a university is a city within a city. So, I do want to acknowledge it’s not always easy.

I’m going to run through three scenarios that people might find themselves in this winter. Can you weigh in on what can be done to improve air flow?

a. On public transit or in a taxi

If you’re on a bus, streetcar or taxi, open a window. There was an interesting study [Science Advances] done around where’s the best place to sit in a taxi – in the backseat, kitty-corner to the driver.

They came to that conclusion not by measuring distance, but by modelling airflow when you have the windows open. But regardless of where you’re sitting, open the windows and let the air move through. And wear an N95 mask. That’s what people should be doing to stay maximally safe.

b. In your own home

Part of it will depend on who else is in your home. Do you share air with other dwellings? Condos and apartment buildings might have a higher risk profile depending on how air moves. But even if you’re in a single-family house and you have control of your own air, then you still want to ask: What are the risks in my house?

In my case, we’ve got two kids. One of them is under 12 and they’re both in school. They’re getting exposed to a lot of other kids and the younger one is not vaccinated. What we did at my home last fall was buy portable HEPA filters – about eight of them. I thought: If someone comes home with COVID-19, we may see transmission before we know it’s a problem. We’re not going to wear masks at home, so I thought we should be scrubbing the air as much as possible.

Opening your door or window for 10 minutes can be transformational. If you want to measure carbon dioxide in your house, you can buy a detector – which I recommend – and you can really start to get a sense of what it takes, in terms of human activity in one room, for carbon dioxide to go way up, and what it takes in terms of opening a window or a door for 10 minutes for carbon dioxide levels to go back down.

So, it’s opening windows, periodically measuring carbon dioxide and deploying HEPA filters.

c. In a bar or restaurant

Unfortunately, my advice is not to go. At this point in the pandemic, sharing air with people who you don’t know and not wearing a mask while you’re indoors is not something I would do. I’ll re-evaluate that position when I see HEPA filters in restaurants, in gyms or in public places where people are together and not wearing masks. This, to me, is extremely high risk.

We should be putting up HEPA filters in restaurants, gyms, movie theatres and other kinds of places where people are going to be gathered together and not wearing masks.

My family loves to support our local businesses by getting takeout and that’s what we’ll keep doing until COVID-19 is subdued or we know that we’re getting clean, scrubbed air in a restaurant.

Is an air purifier a useful investment for a household?

I’m a big fan of portable HEPA filters. You do need to change the filters periodically. But the filters can be vacuumed and their life can be extended. It doesn’t need to be extremely expensive. They help with a lot – with allergies, mould, and all kinds of bacterial spores in the air.

I have just purchased a HEPA unit for my furnace as well. It’s a long-term investment in air quality – above and beyond COVID-19.

See the full article here .


Please help promote STEM in your local schools.

Stem Education Coalition

The The University of Toronto (CA) is a public research university in Toronto, Ontario, Canada, located on the grounds that surround Queen’s Park. It was founded by royal charter in 1827 as King’s College, the oldest university in the province of Ontario.

Originally controlled by the Church of England, the university assumed its present name in 1850 upon becoming a secular institution.

As a collegiate university, it comprises eleven colleges each with substantial autonomy on financial and institutional affairs and significant differences in character and history. The university also operates two satellite campuses located in Scarborough and Mississauga.

University of Toronto has evolved into Canada’s leading institution of learning, discovery and knowledge creation. We are proud to be one of the world’s top research-intensive universities, driven to invent and innovate.

Our students have the opportunity to learn from and work with preeminent thought leaders through our multidisciplinary network of teaching and research faculty, alumni and partners.

The ideas, innovations and actions of more than 560,000 graduates continue to have a positive impact on the world.

Academically, the University of Toronto is noted for movements and curricula in literary criticism and communication theory, known collectively as the Toronto School.

The university was the birthplace of insulin and stem cell research, and was the site of the first electron microscope in North America; the identification of the first black hole Cygnus X-1; multi-touch technology, and the development of the theory of NP-completeness.

The university was one of several universities involved in early research of deep learning. It receives the most annual scientific research funding of any Canadian university and is one of two members of the Association of American Universities (US) outside the United States, the other being McGill(CA).

The Varsity Blues are the athletic teams that represent the university in intercollegiate league matches, with ties to gridiron football, rowing and ice hockey. The earliest recorded instance of gridiron football occurred at University of Toronto’s University College in November 1861.

The university’s Hart House is an early example of the North American student centre, simultaneously serving cultural, intellectual, and recreational interests within its large Gothic-revival complex.

The University of Toronto has educated three Governors General of Canada, four Prime Ministers of Canada, three foreign leaders, and fourteen Justices of the Supreme Court. As of March 2019, ten Nobel laureates, five Turing Award winners, 94 Rhodes Scholars, and one Fields Medalist have been affiliated with the university.

Early history

The founding of a colonial college had long been the desire of John Graves Simcoe, the first Lieutenant-Governor of Upper Canada and founder of York, the colonial capital. As an University of Oxford (UK)-educated military commander who had fought in the American Revolutionary War, Simcoe believed a college was needed to counter the spread of republicanism from the United States. The Upper Canada Executive Committee recommended in 1798 that a college be established in York.

On March 15, 1827, a royal charter was formally issued by King George IV, proclaiming “from this time one College, with the style and privileges of a University … for the education of youth in the principles of the Christian Religion, and for their instruction in the various branches of Science and Literature … to continue for ever, to be called King’s College.” The granting of the charter was largely the result of intense lobbying by John Strachan, the influential Anglican Bishop of Toronto who took office as the college’s first president. The original three-storey Greek Revival school building was built on the present site of Queen’s Park.

Under Strachan’s stewardship, King’s College was a religious institution closely aligned with the Church of England and the British colonial elite, known as the Family Compact. Reformist politicians opposed the clergy’s control over colonial institutions and fought to have the college secularized. In 1849, after a lengthy and heated debate, the newly elected responsible government of the Province of Canada voted to rename King’s College as the University of Toronto and severed the school’s ties with the church. Having anticipated this decision, the enraged Strachan had resigned a year earlier to open Trinity College as a private Anglican seminary. University College was created as the nondenominational teaching branch of the University of Toronto. During the American Civil War the threat of Union blockade on British North America prompted the creation of the University Rifle Corps which saw battle in resisting the Fenian raids on the Niagara border in 1866. The Corps was part of the Reserve Militia lead by Professor Henry Croft.

Established in 1878, the School of Practical Science was the precursor to the Faculty of Applied Science and Engineering which has been nicknamed Skule since its earliest days. While the Faculty of Medicine opened in 1843 medical teaching was conducted by proprietary schools from 1853 until 1887 when the faculty absorbed the Toronto School of Medicine. Meanwhile the university continued to set examinations and confer medical degrees. The university opened the Faculty of Law in 1887, followed by the Faculty of Dentistry in 1888 when the Royal College of Dental Surgeons became an affiliate. Women were first admitted to the university in 1884.

A devastating fire in 1890 gutted the interior of University College and destroyed 33,000 volumes from the library but the university restored the building and replenished its library within two years. Over the next two decades a collegiate system took shape as the university arranged federation with several ecclesiastical colleges including Strachan’s Trinity College in 1904. The university operated the Royal Conservatory of Music from 1896 to 1991 and the Royal Ontario Museum from 1912 to 1968; both still retain close ties with the university as independent institutions. The University of Toronto Press was founded in 1901 as Canada’s first academic publishing house. The Faculty of Forestry founded in 1907 with Bernhard Fernow as dean was Canada’s first university faculty devoted to forest science. In 1910, the Faculty of Education opened its laboratory school, the University of Toronto Schools.

World wars and post-war years

The First and Second World Wars curtailed some university activities as undergraduate and graduate men eagerly enlisted. Intercollegiate athletic competitions and the Hart House Debates were suspended although exhibition and interfaculty games were still held. The David Dunlap Observatory in Richmond Hill opened in 1935 followed by the University of Toronto Institute for Aerospace Studies in 1949. The university opened satellite campuses in Scarborough in 1964 and in Mississauga in 1967. The university’s former affiliated schools at the Ontario Agricultural College and Glendon Hall became fully independent of the University of Toronto and became part of University of Guelph (CA) in 1964 and York University (CA) in 1965 respectively. Beginning in the 1980s reductions in government funding prompted more rigorous fundraising efforts.

Since 2000

In 2000 Kin-Yip Chun was reinstated as a professor of the university after he launched an unsuccessful lawsuit against the university alleging racial discrimination. In 2017 a human rights application was filed against the University by one of its students for allegedly delaying the investigation of sexual assault and being dismissive of their concerns. In 2018 the university cleared one of its professors of allegations of discrimination and antisemitism in an internal investigation after a complaint was filed by one of its students.

The University of Toronto was the first Canadian university to amass a financial endowment greater than c. $1 billion in 2007. On September 24, 2020 the university announced a $250 million gift to the Faculty of Medicine from businessman and philanthropist James C. Temerty- the largest single philanthropic donation in Canadian history. This broke the previous record for the school set in 2019 when Gerry Schwartz and Heather Reisman jointly donated $100 million for the creation of a 750,000-square foot innovation and artificial intelligence centre.


Since 1926 the University of Toronto has been a member of the Association of American Universities (US) a consortium of the leading North American research universities. The university manages by far the largest annual research budget of any university in Canada with sponsored direct-cost expenditures of $878 million in 2010. In 2018 the University of Toronto was named the top research university in Canada by Research Infosource with a sponsored research income (external sources of funding) of $1,147.584 million in 2017. In the same year the university’s faculty averaged a sponsored research income of $428,200 while graduate students averaged a sponsored research income of $63,700. The federal government was the largest source of funding with grants from the Canadian Institutes of Health Research; the Natural Sciences and Engineering Research Council; and the Social Sciences and Humanities Research Council amounting to about one-third of the research budget. About eight percent of research funding came from corporations- mostly in the healthcare industry.

The first practical electron microscope was built by the physics department in 1938. During World War II the university developed the G-suit- a life-saving garment worn by Allied fighter plane pilots later adopted for use by astronauts.Development of the infrared chemiluminescence technique improved analyses of energy behaviours in chemical reactions. In 1963 the asteroid 2104 Toronto was discovered in the David Dunlap Observatory (CA) in Richmond Hill and is named after the university. In 1972 studies on Cygnus X-1 led to the publication of the first observational evidence proving the existence of black holes. Toronto astronomers have also discovered the Uranian moons of Caliban and Sycorax; the dwarf galaxies of Andromeda I, II and III; and the supernova SN 1987A. A pioneer in computing technology the university designed and built UTEC- one of the world’s first operational computers- and later purchased Ferut- the second commercial computer after UNIVAC I. Multi-touch technology was developed at Toronto with applications ranging from handheld devices to collaboration walls. The AeroVelo Atlas which won the Igor I. Sikorsky Human Powered Helicopter Competition in 2013 was developed by the university’s team of students and graduates and was tested in Vaughan.

The discovery of insulin at the University of Toronto in 1921 is considered among the most significant events in the history of medicine. The stem cell was discovered at the university in 1963 forming the basis for bone marrow transplantation and all subsequent research on adult and embryonic stem cells. This was the first of many findings at Toronto relating to stem cells including the identification of pancreatic and retinal stem cells. The cancer stem cell was first identified in 1997 by Toronto researchers who have since found stem cell associations in leukemia; brain tumors; and colorectal cancer. Medical inventions developed at Toronto include the glycaemic index; the infant cereal Pablum; the use of protective hypothermia in open heart surgery; and the first artificial cardiac pacemaker. The first successful single-lung transplant was performed at Toronto in 1981 followed by the first nerve transplant in 1988; and the first double-lung transplant in 1989. Researchers identified the maturation promoting factor that regulates cell division and discovered the T-cell receptor which triggers responses of the immune system. The university is credited with isolating the genes that cause Fanconi anemia; cystic fibrosis; and early-onset Alzheimer’s disease among numerous other diseases. Between 1914 and 1972 the university operated the Connaught Medical Research Laboratories- now part of the pharmaceutical corporation Sanofi-Aventis. Among the research conducted at the laboratory was the development of gel electrophoresis.

The University of Toronto is the primary research presence that supports one of the world’s largest concentrations of biotechnology firms. More than 5,000 principal investigators reside within 2 kilometres (1.2 mi) from the university grounds in Toronto’s Discovery District conducting $1 billion of medical research annually. MaRS Discovery District is a research park that serves commercial enterprises and the university’s technology transfer ventures. In 2008, the university disclosed 159 inventions and had 114 active start-up companies. Its SciNet Consortium operates the most powerful supercomputer in Canada.