PSA: keep masking when flying!

[wathe]

1 minute ago, Not_a_Number said:

Yes, thank you very very much for posting the ones you use upthread. I've been pondering whether I want to get one or not. Honestly, I haven't decided where we we want to go with our COVID strategies now that we've had it. On the one hand, I've been enjoying not worrying about it. On the other hand... well, I just haven't thought about it much. 

I need to talk all his over with DH, too. Decisions, decisions. 

I really, really appreciate knowing the numbers. Thank you so much for that other thread and the pointers to the data. 

Oh, you want one!!!!  You are a data person, I think.  It's quite empowering to be able to get the data yourself.  And be able to use it to make decisions in real time.

It is the best toy.

 

[Not_a_Number]

Just now, wathe said:

Oh, you want one!!!!  You are a data person, I think.  It's quite empowering to be able to get the data yourself.  And be able to use it to make decisions in real time.

It is the best toy.

Hahahahahah. OK, I admit it, you're getting through to me here. I am absolutely a data person, of course. 

The thing is is that I've liked not having it hanging over me. Making decisions in real time means that it has to stay PRESENT. It was a real mental strain for me for it to be so present. I've felt much happier not worrying about it. 

I just really haven't sorted out what I feel. And I don't think DH has, either. 

But I am absolutely pondering getting one! And I've found your results really intriguing! It's crazy that giant gyms have such bad CO2 concentrations. I would have never guessed. 

[wathe]

5 minutes ago, Not_a_Number said:

Hahahahahah. OK, I admit it, you're getting through to me here. I am absolutely a data person, of course. 

The thing is is that I've liked not having it hanging over me. Making decisions in real time means that it has to stay PRESENT. It was a real mental strain for me for it to be so present. I've felt much happier not worrying about it. 

I just really haven't sorted out what I feel. And I don't think DH has, either. 

But I am absolutely pondering getting one! And I've found your results really intriguing! It's crazy that giant gyms have such bad CO2 concentrations. I would have never guessed. 

Having the data to make good decisions has actually been pretty freeing for me.  

If you use a monitor that stores data, you don't necessarily have to be looking at it all the time.  Rather analyze the data retrospectively to see the patterns.  If the patterns remain consistent over time, then you don't even need the monitor to know whether or not to mask in certain situations anymore - you will know that planes are reliably bad, and x grocery store is reliably good, and y bus is reliably middling, kid's school classroom a is good but b is bad etc.

I used mine yesterday to titrate the ventilation at a group retreat, to optimize safety for those who wanted to unmask.

 

[KSera]

2 minutes ago, wathe said:

Having the data to make good decisions has actually been pretty freeing for me.

I’m super glad to have it and more data is always better than less data to me, but I have to say I’ve had a couple situations I wished I hadn’t looked! They were both medical situations that I couldn’t leave because my kids needed care and the numbers were terrible. (These were clinics, not hospital situations—I was very pleased with readings at the hospital.)

[Not_a_Number]

5 minutes ago, wathe said:

Having the data to make good decisions has actually been pretty freeing for me.  

If you use a monitor that stores data, you don't necessarily have to be looking at it all the time.  Rather analyze the data retrospectively to see the patterns.  If the patterns remain consistent over time, then you don't even need the monitor to know whether or not to mask in certain situations anymore - you will know that planes are reliably bad, and x grocery store is reliably good, and y bus is reliably middling, kid's school classroom a is good but b is bad etc.

I used mine yesterday to titrate the ventilation at a group retreat, to optimize safety for those who wanted to unmask.

I'm not sure what to say here. I know that for me having the WEIGHT of it all the time is taxing. 

 

1 minute ago, KSera said:

I’m super glad to have it and more data is always better than less data to me, but I have to say I’ve had a couple situations I wished I hadn’t looked! They were both medical situations that I couldn’t leave because my kids needed care and the numbers were terrible. (These were clinics, not hospital situations—I was very pleased with readings at the hospital.)

Yeah, exactly. Data is good if I know what I'm going to do with it as opposed to just worry about it. If it's just adding stress, I don't want it. 

That's why I was interested in the airplane data, to be honest. It's not going to require thought. We're just going to mask and not eat when flying. It's obvious. I need to figure out a way to make our masks comfier (my ears feel ON FIRE after wearing one of our standard KF94s for 6 hours), but other than that, there are no decisions to be made. Now we know. 

But I have literally not through anything else yet. I need to. The data helps. 

[wathe]

15 minutes ago, Not_a_Number said:

I'm not sure what to say here. I know that for me having the WEIGHT of it all the time is taxing. 

 

Yeah, exactly. Data is good if I know what I'm going to do with it as opposed to just worry about it. If it's just adding stress, I don't want it. 

That's why I was interested in the airplane data, to be honest. It's not going to require thought. We're just going to mask and not eat when flying. It's obvious. I need to figure out a way to make our masks comfier (my ears feel ON FIRE after wearing one of our standard KF94s for 6 hours), but other than that, there are no decisions to be made. Now we know. 

But I have literally not through anything else yet. I need to. The data helps. 

Right.  The CO2 pattern on a plane is reliable and constant (ETA bad word choice - I mean it reliably repeats over time) over time.  So, you make a behaviour change on planes that becomes your norm, and you don't have to think about it any more.

There may be other indoor spaces in your life that will have similar reliable and constant CO2 patterns, for which you can make a behavioural standard for yourself (whether that's masking in that space, or not masking in that space, or something else), and not have to think about it any more.

In my own life, my parents house is an example of this. We know, based on CO2, that it's badly ventilated. So, when we visit, we crack windows and run the CR box as a matter of course.  It's just become our behavioural standard, which we don't have to think about anymore.

Edited November 5, 2022 by wathe

[wathe]

Another example:  I will unmask and eat in a very well spaced break-room in the hospital now, because the pattern of excellent ventilation is reliable and has repeats over time.  I don't need to worry about it anymore.

[Not_a_Number]

4 minutes ago, wathe said:

Right.  The CO2 pattern on a plane is reliable and constant (ETA bad word choice - I mean it reliably repeats over time) over time.  So, you make a behaviour change on planes that becomes your norm, and you don't have to think about it any more.

There may be other indoor spaces in your life that will have similar reliable and constant CO2 patterns, for which you can make a behavioural standard for yourself (whether that's masking in that space, or not masking in that space, or something else), and not have to think about it any more.

In my own life, my parents house is an example of this. We know, based on CO2, that it's badly ventilated. So, when we visit, we crack windows and run the CR box as a matter of course.  It's just become our behavioural standard, which we don't have to think about anymore.

Yes. This would be the kind of thing I might be interested in doing. But first I'd have to figure out what it is I'm trying to do. 

I had a really bad reaction to both the second shot of the vaccine and the first booster -- 2 weeks of very noticeable headache at the back of my head, and then another couple of weeks where I could feel dull twinges. I have chronic tension headaches as is and am frankly afraid to get the next booster. DH was saying he was afraid I'd get a new chronic condition after the vaccines 😕 . 

I guess what I'm saying is, given my personal experiences, I don't even know if I'm TRYING to avoid COVID right now or not. I haven't figured that out 😕 . 

However, in general, as all airborne viruses are spread more in poorly ventilated areas, I will probably come down on the side of wanting to know. But all I'm sure about right now is that I need some processing time to figure out what I'm doing 😕 . 

[kbutton]

11 minutes ago, Not_a_Number said:

I have chronic tension headaches 

My physical therapist told me this week that sometimes tucking your chin and pulling your head back as if you are trying to look like you have a double chin can help with tension headaches. She says it's not 100% but can often make a big difference. 

[Not_a_Number]

1 minute ago, kbutton said:

My physical therapist told me this week that sometimes tucking your chin and pulling your head back as if you are trying to look like you have a double chin can help with tension headaches. She says it's not 100% but can often make a big difference. 

I don't think mine are super easily amenable to physical stuff. At least, nothing I've ever tried works. I'll try it, but I am skeptical. (I've had them since I was 16 or so so I'm very used to them.) 

Mine seem extremely connected to my sleep hormones. Oddly enough, when I was getting up all night with the kids, I didn't get them -- there's something about one of the stages of deep sleep that might trigger them for me, I think (or maybe it's being awakened in the middle of those stages? I'm not sure.) 

Thank you for the suggestion, though! It's always good to have things to try. 

[kbutton]

3 minutes ago, Not_a_Number said:

there's something about one of the stages of deep sleep that might trigger them for me, I think (or maybe it's being awakened in the middle of those stages? I'm not sure.) 

Interesting! I wonder if you move into a position that causes them during deep sleep? Tension headaches are the worst. I would rather have a migraine.

[Not_a_Number]

1 minute ago, kbutton said:

Interesting! I wonder if you move into a position that causes them during deep sleep? Tension headaches are the worst. I would rather have a migraine.

I would guess not. I can also feel a transition in the middle of the day from no headache to headache or vice versa, right around when I get sleepy, even if I don't allow myself to fall asleep. I believe that's the point your body switches from keeping you awake with one hormone versus another? I remember reading up about it. 

It's all very odd. I have years worth of data, and the only thing that ever made a difference was waking up at the same time every day, including weekends. I've been thinking about trying an experiment sometime where I let the light wake me up every day (I use an alarm for that right now.) 

Edited November 5, 2022 by Not_a_Number

[Matryoshka]

3 hours ago, KSera said:

I‘m sure people have taken readings. I haven’t been on a bus since the pandemic started, so haven’t been able to take a reading. Even our car with just two people in it builds up CO2. Opening the windows confounds things in a car because CO2 readings elevate from combustion engines nearby. We have to be away from other cars for us to get a relevant reading with windows down (our car is electric, so not contributing CO2).

I've actually been surprised at how decent the CO2 levels stay in our car if we have the outside vents and fan on, even with the windows closed. I'm guessing it could build up fast if you were in city traffic or idling - I think I've mostly checked this while driving on the highway, as that's where it's harder to keep windows down.

Edited November 5, 2022 by Matryoshka

[kbutton]

20 minutes ago, Not_a_Number said:

It's all very odd. I have years worth of data, and the only thing that ever made a difference was waking up at the same time every day, including weekends.

That is odd! I hope you find something that helps. I like waking up with the light. I live far enough west of where I grew up that it really messes up my sleep/wake times. I naturally go to bed earlier and get up later when I visit my parents and experience their daylight hours, especially in the summer. We are in the same time zone, but it's far enough to matter to my biological clock.

I wonder if there is a food or supplement that would help that hormonal shift.

[Matryoshka]

1 hour ago, wathe said:

Oh, you want one!!!!  You are a data person, I think.  It's quite empowering to be able to get the data yourself.  And be able to use it to make decisions in real time.

It is the best toy.

I gotta agree. And it's given me great peace of mind while cooped up in a tiny apartment with dd who tested positive on arrival. Sleeping/sitting next to an open window, the CO2 numbers are pretty much like outdoors (she's sleeping in another room), so I felt fine taking my mask off there (Masking indoors while out doesn't bother me at all, but really don't want to wear them all day, or night, when at home).  She's tested negative twice now, so Knock Wood that all the Swiss cheese layers of avoidance worked... (and good thing we both wore N95s on the plane/in airport).

[kbutton]

12 minutes ago, Matryoshka said:

I've actually been surprised at how de ent the CO2 levels stay in our car if we have the outside vents and fan on, even with the windows closed. I'm guessing it could build up fast if you were in city traffic or idling - I think I've mostly checked this while driving on the highway, as that's where it's harder to keep windows down.

I am curious about recirculating the air by comparison. For people with allergies, that's recommended, but it's also recommended to keep the cabin air filter up-to-date. It also cuts down on breathing fumes from other cars.

[Matryoshka]

5 minutes ago, kbutton said:

I am curious about recirculating the air by comparison. For people with allergies, that's recommended, but it's also recommended to keep the cabin air filter up-to-date. It also cuts down on breathing fumes from other cars.

Yeah, if you recirculate the air, you're not exchanging air, so I think it goes up pretty fast.  When I get home I can play around with it for comparison. 

It's just really hard to keep the windows down when at cruising speed on the highway,  so it's good to know the vents/fan seem to work.  Honestly,  if the windows are open instead, you're still getting fumes and pollen, but with a side of deafening noise and crazy hair...

I still always open the windows when not alone on side roads or in traffic. And wear a mask if in the car with someone other than dh.  Swiss cheese again.

Edited November 5, 2022 by Matryoshka

[kbutton]

1 minute ago, Matryoshka said:

Yeah, if you recirculate the air, you're not exchanging air, so I think it goes up pretty fast.  When I get home I can play around with it for comparison. 

It's just really hard to keep the windows down when at cruising speed on the highway,  so it's good to know the vents/fan seem to work.  Honestly,  if the windows are open instead, you're still getting fumes and pollen, but with a side of deafening noise and crazy hair...

I don't know if a meter would account for pollen, which is why the recommendations are the way they are.

I also don't know if recirculate draws in any air or not--it may draw in less. The filter should make a difference; that's why people make the Corsi-Rosenthal boxes. 

I am really sensitive to indoor air quality, and I don't have trouble on long car rides with the air recirculating. 

[Matryoshka]

1 minute ago, kbutton said:

I don't know if a meter would account for pollen, which is why the recommendations are the way they are.

I also don't know if recirculate draws in any air or not--it may draw in less. The filter should make a difference; that's why people make the Corsi-Rosenthal boxes. 

I am really sensitive to indoor air quality, and I don't have trouble on long car rides with the air recirculating. 

I thought recirculating meant just that - that the air is recirculated rather than coming from outside.  Where is the air filter, anyone know?  I'll admit to ignorance.  Is it filtering outside air, recirculated air or both?  I'd assume the first, but I have no idea.  I'd think the filter would be to remove outside contaminants - what would it be filtering on recirculate (in a pre-Covid world...).

The meter of course doesn't care about pollen, but that comes through open windows too.

[kbutton]

1 minute ago, Matryoshka said:

I thought recirculating meant just that - that the air is recirculated rather than coming from outside.  Where is the air filter, anyone know?  I'll admit to ignorance.  Is it filtering outside air, recirculated air or both?  I'd assume the first, but I have no idea.  I'd think the filter would be to remove outside contaminants - what would it be filtering on recirculate (in a pre-Covid world...).

The meter of course doesn't care about pollen, but that comes through open windows too.

I am really talking about recirculated vs. the vent, not windows open, when it comes to pollen.

I assume the recirculate is not a completely closed system, but I could be wrong. I would think we'd have drivers passing out if that were the case, lol! 

I believe the filter is going to filter whatever is circulating--indoor air, outdoor air, etc. Even a closed up house has new air coming in to some extent, unless it's one of those super tight homes (and they usually build better air exchange in to the HVAC to compensate for that, IIRC).

I'm not trying to get into the deep weeds. I really am just curious because I often can't tolerate using the vents much less having windows down a bunch. I also don't really ride with people outside of my immediate family.

 

[kbutton]

Perhaps of interest: https://pubmed.ncbi.nlm.nih.gov/9470106/

Quote

The air exchange rates or air changes per hour (ACH) were measured under 4 conditions in 3 stationary automobiles. The ACH ranged between 1.0 and 3.0 h-1 with windows closed and no mechanical ventilation, between 1.8 and 3.7 h-1 for windows closed with fan set on recirculation, between 13.3 and 26.1 h-1 for window open with no mechanical ventilation, and between 36.2 and 47.5 h-1 for window closed with the fan set on fresh air. ACHs for windows closed with no ventilation were higher for the older automobile than for the newer automobiles. 

I don't know how to translate air changes per hour into helpful air quality measures. Air changes per hour is definitely discussed in relation to air filtration in buildings.

@Matryoshka

Edited November 5, 2022 by kbutton

[Matryoshka]

13 minutes ago, kbutton said:

I don't know if a meter would account for pollen, which is why the recommendations are the way they are.

I also don't know if recirculate draws in any air or not--it may draw in less. The filter should make a difference; that's why people make the Corsi-Rosenthal boxes. 

I am really sensitive to indoor air quality, and I don't have trouble on long car rides with the air recirculating. 

Okay, did some sleuthing sounds like recirculate does keep out all outside air, (from a YouTube video explaining how recirculation in your car works and how to best use it, from perspectives other than Covid).  

As to where the filter is... did some more research.  Depending on the car, it either filters all air, both recirculated and outside, or just outside.  But it is filtering outside air either way, which means even when not on recirculate, the filter should be filtering out pollen and car exhaust.  But in some cars, it may filter nothing when on recirculate.  Have to know where your filter is, I guess.

 

[kbutton]

1 minute ago, Matryoshka said:

Okay, did some sleuthing sounds like recirculate does keep out all outside air, (from a YouTube video explaining how recirculation in your car works and how to best use it, from perspectives other than Covid).  

I don't think that's possible. I think you could turn on your car with the garage door down, turn on recirculate, and still die of carbon monoxide poisoning. 

Cars are not hermetically sealed. 

[Matryoshka]

Just now, kbutton said:

I don't think that's possible. I think you could turn on your car with the garage door down, turn on recirculate, and still die of carbon monoxide poisoning. 

Cars are not hermetically sealed. 

True, but it would take a lot longer than if you take a hose and put it in the window. 😱

We're talking about trying to avoid Covid while driving in a car cabin with a possibly infected person.  A car may not be hermetically sealed, but you need a lot of outside air exchange to keep the CO2 buildup in the cabin down to a good level.  Recirculate doesn't seem to do that (though if you have a nice, clean, high-grade filter in a car where recirculate uses it, I do wonder if that might still keep things comparatively low risk).   I'm guessing, though, most people have not paid much attention to the quality or location of their air filters.

My house is built in 1880 and the furthest thing from hermetically sealed.  I kinda assumed our CO2 levels even with the single pane windows closed would be reasonably good - but they actually go up pretty fast without a window actually open.

[mommyoffive]

2 hours ago, wathe said:

Having the data to make good decisions has actually been pretty freeing for me.  

If you use a monitor that stores data, you don't necessarily have to be looking at it all the time.  Rather analyze the data retrospectively to see the patterns.  If the patterns remain consistent over time, then you don't even need the monitor to know whether or not to mask in certain situations anymore - you will know that planes are reliably bad, and x grocery store is reliably good, and y bus is reliably middling, kid's school classroom a is good but b is bad etc.

I used mine yesterday to titrate the ventilation at a group retreat, to optimize safety for those who wanted to unmask.

 

What level do you unmask indoors for?

[kbutton]

Just now, Matryoshka said:

We're talking about trying to avoid Covid while driving in a car cabin with a possibly infected person. 

I thought I made it pretty clear that I was curious about the adequacy of air quality, in general, with recirculate. 🙂 

[Matryoshka]

7 minutes ago, kbutton said:

I thought I made it pretty clear that I was curious about the adequacy of air quality, in general, with recirculate. 🙂 

Ah.  Well, if they suggest turning the system off every hour for half an hour to let more oxygen in... 

Don't get me wrong, I totally turn recirculate on in the summer with AC if I'm alone in the car.  I was talking about using it when in the car with non-household members so i guess we were talking past each other a bit. 😅

Edited November 5, 2022 by Matryoshka

[wathe]

1 hour ago, mommyoffive said:

What level do you unmask indoors for?

We aimed for ppm CO2 less than 800.

I stayed masked Unless eating, and while eating Strategically parked myself right beside an open window.

[KSera]

7 hours ago, Not_a_Number said:

I need to figure out a way to make our masks comfier (my ears feel ON FIRE after wearing one of our standard KF94s for 6 hours),

I know people tend to hate the head straps on an N95, but I find it infinitely more comfortable to wear head straps all day than to have the ear straps as tight as they need to be. I can only do that for about an hour and a half before I’m looking forward to getting the pressure off my ears. 

5 hours ago, Matryoshka said:

It's just really hard to keep the windows down when at cruising speed on the highway,  so it's good to know the vents/fan seem to work.  Honestly,  if the windows are open instead, you're still getting fumes and pollen, but with a side of deafening noise and crazy hair...

Agree on the Highway speed window thing. We have had to do it a few times and it’s not much fun. He have cabin filters accessible from inside the cabin, but it’s hard to find Hepa ones. As a side note, the CO2 readings can no longer  guide you when you are relying on mechanical filtration; the filter is not going to filter carbon dioxide out of the air, obviously.  So, there can be environments where the CO2 reading is higher than you want, but if you have really good mechanical filtration running, like a Corsi Rosenthal box in a small room, your actual risk will be a good deal lower than what the CO2 reading might indicate.

 

[Not_a_Number]

1 minute ago, KSera said:

I know people tend to hate the head straps on an N95, but I find it infinitely more comfortable to wear head straps all day than to have the ear straps as tight as they need to be. I can only do that for about an hour and a half before I’m looking forward to getting the pressure off my ears. 

I should try it. As you say, I can't do pressure on my ears for more than an hour and a bit. 

Where do the N95s put pressure? 

[KSera]

24 minutes ago, Not_a_Number said:

Where do the N95s put pressure? 

On your face. Which is where you want it for a tight seal. I use primarily a 3M aura. 
 

[Not_a_Number]

4 minutes ago, KSera said:

On your face. Which is where you want it for a tight seal. I use primarily a 3M aura. 
 

But they go around the back of your head, right? Do they press on your neck, say? 

I should just try it, of course. Just thinking out loud here. I don't always do well with neck pressure, either. (I'm pain sensitive, period, alas.) 

[KSera]

6 minutes ago, Not_a_Number said:

But they go around the back of your head, right? Do they press on your neck, say? 

I should just try it, of course. Just thinking out loud here. I don't always do well with neck pressure, either. (I'm pain sensitive, period, alas.) 

The top strap goes over the crown of your head, the bottom one around the back (yes, on your neck). My neck sucks, but I don’t find that’s where I feel any pressure from the mask. whatsoever. You’d have to try. I make sure I have a band or clip in my hair on out of the house days so that the top strap can rest on that to not slip. With the ear loops, you can get various kinds of ear savers or mask locks to hold them tight without using your ears. The ones with two anchor points seem to do it best. 

[Not_a_Number]

Just now, KSera said:

The top strap goes over the crown of your head, the bottom one around the back (yes, on your neck). My neck sucks, but I don’t find that’s where I feel any pressure from the mask. whatsoever. You’d have to try. I make sure I have a band or clip in my hair on out of the house days so that the top strap can rest on that to not slip. With the ear loops, you can get various kinds of ear savers or mask locks to hold them tight without using your ears. The ones with two anchor points seem to do it best. 

Yes, I've done that with the looped ones. I've had mixed luck, but it's definitely better than just hanging on my ears. 

[Ausmumof3]

11 hours ago, Not_a_Number said:

I don't think mine are super easily amenable to physical stuff. At least, nothing I've ever tried works. I'll try it, but I am skeptical. (I've had them since I was 16 or so so I'm very used to them.) 

Mine seem extremely connected to my sleep hormones. Oddly enough, when I was getting up all night with the kids, I didn't get them -- there's something about one of the stages of deep sleep that might trigger them for me, I think (or maybe it's being awakened in the middle of those stages? I'm not sure.) 

Thank you for the suggestion, though! It's always good to have things to try. 

Did you breastfeed? My sis has them linked to ovulation so if you weren’t ovulating that may have suppressed them.

[wathe]

@kbutton

@Matryoshka

Re car ventilation.  There are some studies on car ventilation that are interesting:  

Airflows inside passenger cars and implications for airborne disease transmission

Air change rates of motor vehicles and in-vehicle pollutant concentrations from secondhand smoke

The second one has data in the abstract: "With the vehicle stationary and the fan off, the ventilation rate in air changes per hour (ACH) was less than 1 h−1 ........For closed windows and passive ventilation(fan off and no recirculation), the ACH was linearly related to the vehicle speed over the range from 15 to 72 mph (25 to 116 km h−1)"

Cars are not air-tight.  There is passive air leakage.  But the air in a closed car without mech ventilation turned on does get stale quickly.

My own CO2 data:  I can keep ppm CO2 to less than 800 with 4 people in the car, with just the ventilation going at 3/4 speed, windows closed.  When the vent system is set to recirc, the CO2 shoots up (DH did this inadvertently once, and the CO2 monitor happened to be with us)

[wathe]

Re Car data:

I ran a little experiment on my trip to and from work today

On the way to work, I set the ventilation to recirculate.  Fan speed 4/7.  20km trip, 12 of which are rural highway at a cruising speed of 90 kph, trip time just under 20min.   CO2 rose rapidly and kept on rising. Peak CO2 1743ppm, with a steep slope that had no signs of leveling off (suggesting that the CO2 would have kept rising if the trip had been longer)

On the way home, everything the same, except set to fresh air instead of recirc.  Peak CO2 582ppm, with the peak right at the beginning of the trip (I assume because there is a minute or so of time where I am in the car without the ventilation running before I get the car turned on) with a slow fall to 515ppm.

Dramatic difference.

 

Edited November 7, 2022 by wathe

[wathe]

A Twitter thread with Aranet4 data from a train.  Peaked at 3038ppm:

 

[wathe]

Another one with lots of data on VIA rail trains.  I expect most inter-city passenger trains in North America are similar.

 

 

[wathe]

Study with CO2 data from public city buses:

https://www.sciencedirect.com/science/article/pii/S0013935121017527

Edited November 7, 2022 by wathe

[Ausmumof3]

4 hours ago, wathe said:

Re Car data:

I ran a little experiment on my trip to and from work today

On the way to work, I set the ventilation to recirculate.  Fan speed 4/7.  20km trip, 12 of which are rural highway at a cruising speed of 90 kph, trip time just under 20min.   CO2 rose rapidly and kept on rising. Peak CO2 1743ppm, with a steep slope that had no signs of leveling off (suggesting that the CO2 would have kept rising if the trip had been longer)

On the way home, everything the same, except set to fresh air instead of recirc.  Peak CO2 582ppm, with the peak right at the beginning of the trip (I assume because there is a minute or so of time where I am in the car without the ventilation running before I get the car turned on) with a slow fall to 515ppm.

Dramatic difference.

 

Wow! I have relied on windows cracked the couple of times I had to transport someone and was worried about illness but that’s reassuring. I wonder if it differs much between vehicles.

[Matryoshka]

6 minutes ago, Ausmumof3 said:

Wow! I have relied on windows cracked the couple of times I had to transport someone and was worried about illness but that’s reassuring. I wonder if it differs much between vehicles.

Yeah, this is what I had been trying to get across but didn't have exact numbers to quote. Makes me feel much better about not having to keep the windows open on the highway, where it's super loud and you feel like you're in a wind tunnel.  I do think speed factors in - when the car us moving more slowly,  I still like to have the windows open. 

[kbutton]

8 hours ago, wathe said:

Re Car data:

I ran a little experiment on my trip to and from work today

On the way to work, I set the ventilation to recirculate.  Fan speed 4/7.  20km trip, 12 of which are rural highway at a cruising speed of 90 kph, trip time just under 20min.   CO2 rose rapidly and kept on rising. Peak CO2 1743ppm, with a steep slope that had no signs of leveling off (suggesting that the CO2 would have kept rising if the trip had been longer)

On the way home, everything the same, except set to fresh air instead of recirc.  Peak CO2 582ppm, with the peak right at the beginning of the trip (I assume because there is a minute or so of time where I am in the car without the ventilation running before I get the car turned on) with a slow fall to 515ppm.

Dramatic difference.

 

I am really surprised given how sensitive I seem to be to air quality! 

[EKS]

On 11/5/2022 at 7:08 PM, Not_a_Number said:

Where do the N95s put pressure? 

On 11/5/2022 at 7:39 PM, Not_a_Number said:

But they go around the back of your head, right? Do they press on your neck, say? 

The bottom strap actually goes at the base of your head.  I find that if the top strap is positioned right above the ear, after a while it can be uncomfortable, but I can move it up a bit and it's fine.

There is no way I'd wear anything but an N95 on plane.  First because they are better, but even if they weren't, I'd do it because they are so much more comfortable than masks with ear loops.

[KSera]

8 hours ago, wathe said:

Study with CO2 data from public city buses:

https://www.sciencedirect.com/science/article/pii/S0013935121017527

@Not_a_Number This is one of the studies co-authored by Jose-Luis Jimenez who I linked to above, who made the statement about the doors opening and closing not being sufficient. You can see the data you wanted in it. 

[Spryte]

4 hours ago, EKS said:

The bottom strap actually goes at the base of your head.  I find that if the top strap is positioned right above the ear, after a while it can be uncomfortable, but I can move it up a bit and it's fine.

There is no way I'd wear anything but an N95 on plane.  First because they are better, but even if they weren't, I'd do it because they are so much more comfortable than masks with ear loops.

Yes, N95s are so much more comfortable. I have trigeminal neuralgia (unaffectionately nicknamed “the suicide disease” by Wikipedia — flares are extraordinarily painful). I can’t stand anything on my head or I go into a four day flare with migraines, too. Hats, wigs, even talking on the phone can set it off. For men, shaving can do it. But N95s with the two head straps don’t bother it — it’s amazing. I wear a high bun or ponytail, and anchor the top strap up with that. The bottom strap just goes around the back of my head. 
 

I actually wore one for four days straight, only taking it off to (rarely) eat, when in the hospital at the height of a wave here, pre-vaccines.

Edited November 7, 2022 by Spryte

[regentrude]

5 hours ago, EKS said:

The bottom strap actually goes at the base of your head.  I find that if the top strap is positioned right above the ear, after a while it can be uncomfortable, but I can move it up a bit and it's fine.

There is no way I'd wear anything but an N95 on plane.  First because they are better, but even if they weren't, I'd do it because they are so much more comfortable than masks with ear loops.

This. No way could I wear an ear loop mask that fits tightly enough for an entire day. 
But I wore N95s with head straps for the entire 22 hour trip to and from Germany (had to swap masks in the middle because that long, they get gross)

[Not_a_Number]

12 hours ago, KSera said:

@Not_a_Number This is one of the studies co-authored by Jose-Luis Jimenez who I linked to above, who made the statement about the doors opening and closing not being sufficient. You can see the data you wanted in it. 

Thank you!! Much appreciated.

The numbers actually look relatively reassuring to me, especially as compared to some of the really eye-popping ones I’ve seen!

[Not_a_Number]

12 hours ago, EKS said:

The bottom strap actually goes at the base of your head.  I find that if the top strap is positioned right above the ear, after a while it can be uncomfortable, but I can move it up a bit and it's fine.

There is no way I'd wear anything but an N95 on plane.  First because they are better, but even if they weren't, I'd do it because they are so much more comfortable than masks with ear loops.

DH says he has to wear them for work sometimes and has found them less comfy than ear loop masks 😕. I should try one, though. (I should also try adjusting his…)

[KSera]

15 minutes ago, Not_a_Number said:

DH says he has to wear them for work sometimes and has found them less comfy than ear loop masks

I think that’s because many (most?) people aren’t wearing their ear loop masks tight enough. They don’t bother me if I keep them loose, but I don’t know why I’d be wearing it if I was going to wear it loose.