Thread by @jheighton3

Thread 🧵:
A tale of 2 🇨🇦airports & flights, Vancouver (YVR) & Calgary (YYC), using a CO2 monitor to measure air quality.

@yvrairport @FlyYYC

Here’s a handy graphic for reference: (H/T @zerocovidthai)

2/ @yvrairport requires masks in the terminal, unless eating or drinking. Large signs are posted by entry doors to remind people of this rule.

The vast majority of people are complying. (Proves that universal masking policies DO WORK & “personal choice” ones don’t).

@bcndp?

3/ Vancouver Int’l Airport has 2 terminals, domestic & int’l. I’m in the domestic one. CO2 levels are pretty good, in various places throughout. Reasonably busy time.

One area to potentially avoid: restaurant where it’s crowded & everyone is unmasked to eat.

Alt text more info:

4/ Prior to boarding, it’s announced that masks are mandatory on the flight. Transport Canada rules are that any flight departing from or arriving at a Canadian destination must comply with mandatory mask rules.
(I am wearing a @vitacoreinc N99.)

Link: tc.canada.ca/en/initiatives…

5/ Boarding plane. @WestJet. From reading 🧵 from previous COVID-aware advocates, I knew boarding is the most dangerous time as the plane’s ventilation system is usually off. Hence I booked seats close to the front (boarding last). Even so, CO2 levels were high. Keep 😷on!

6/ Plane is taking off from @yvrairport. CO2 levels start to drop from the last reading of over 1900, but still not low enough yet. The plane’s ventilation system is clearly now on.

2nd photo shows downtown Vancouver w/ mountains & ocean, taken from the plane. ☺️

7/ Cruising. From 10 minutes after takeoff, to landing the plane an hour later, CO2 levels hovered in the 1100-1250 range. On the chart that looks poor, but since planes have good HEPA filtration systems (not shown on CO2), it’s safer than it looks. Kept 😷on though.

8/ Waiting to deplane. The airport is still attaching the walkway to the door. It’s been only 10 minutes since we stopped; CO2 has gone up dramatically in that time.

Luckily I’m sitting close to the front so we are among the first to exit. (If you can, pre-book your seats!)

9/ Calgary airport. Took only 1 reading as we were in a rush to leave.

Definitely better than on the plane but not as good as @yvrairport.

10/ The next tweets document the return journey; Calgary airport @FlyYYC to Vancouver airport @yvrairport. @WestJet again.

I thought it would be the same, but there were some differences! 😮

11/ Tale of 2 airports continued…ready for the return flight!

Calgary airport @FlyYYC’s ventilation is pretty good, like Vancouver @yvrairport. So far, so good.

Photos are of the waiting area at the gate & the washroom. It was decently busy in the terminal at the time.

12/ As anticipated, the moment I boarded, the CO2 reading went up. From low 1200’s on immediate entry, to 1800’s just minutes later.

I had booked a seat close to the front again.

Plane is mostly full (a bit less packed than the first flight).

Alt text has more description.

13/ As expected, at 5 minutes after takeoff, CO2 levels are dropping, to 1353ppm. But here’s the weird part - instead of dropping down to the 1100-1200 range, like the first flight, the levels end up hovering in the 1500-1700 range throughout the flight! Plane HEPA helps, but 😮!

14/ Decending into Vancouver. Finally the CO2 starts dropping again. But it took 1 hour to get back to these levels, which aren’t great to begin with. Again, airplane HEPA filtration helps to lower the risk (which the CO2 monitor doesn’t pick up).

I kept my mask on.

15/ Once the plane lands, the ventilation system is turned off in most planes, and we see that here as the levels start to rise again. Luckily the plane gets to the gate fairly quickly and we are deplaning within 15 minutes.

16/ Last reading of this journey! Vancouver International Airport, domestic terminal, arrival area just before descending to baggage carousels. As expected from prior readings, ventilation is pretty good. It’s a Sunday afternoon, so somewhat busy but not overly so.

17/ If you’d like to read more about airplane flights & ventilation, see this thread & responses by Toronto engineer @joeyfox85.

He’s the real expert! It’s thanks to him & @DavidElfstrom @CPita3 @BarryHunt008 that I’ve learned about the importance of clean air in COVID safety.

https://twitter.com/joeyfox85/status/1545148594289868802

18/ And if you liked this CO2 investigation, you may also like the Downtown Vancouver shopping mall investigation I did in March 2022…
#CovidisAirborne
#CovidIsNotOver

BC Public Health should be informing ALL businesses about ventilation & @bcndp giving tax rebates if fixed!

https://twitter.com/jheighton3/status/1503963482403717123

19/ And the other CO2 investigation thread I wrote was a restaurant comparison - visit was end of June, 2022; thread written in early July.

Note: weather at the time was temperate; low 20’s Celsius.

https://twitter.com/jheighton3/status/1543957758239600640

20/ END

A CO2 monitor is a handy device, especially in crowded, indoor spaces. It helps see if the air is being refreshed enough by the HVAC system, or the opposite, whether you are breathing in too much of other people’s exhaled air, in case someone happens to be infectious.

https://twitter.com/davidelfstrom/status/1468268425617330185