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Training my sense of CO2 ppm

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Re: Training my sense of CO2 ppm

#21

Post by [deleted] »

kadoban wrote: post #13
CoastalCoder wrote: post #10

Earlier quoted context omitted.

From some (personal) research I did several years ago, I think good ventilation is by far the biggest concern. A well-sealed, occupied room can build up significant CO2 levels pretty quickly. In my particular case, one person, not exercising, could bring CO2 above 800ppm (reported) in just a few hours. So I think lack of ventilation causes way, way more excess CO2 than is caused by recent increases in atmospheric CO2…

My issue with that is that in the summer, ventilation is ~impossible. It's 110 degrees out there, reasonable ventilation would mean either burning out my A/C or living with temps that are far too high.

[deleted]

Re: Training my sense of CO2 ppm

#22

Post by jasonpeacock »

CoastalCoder wrote: post #14
kadoban wrote: post #13

Earlier quoted context omitted.

My issue with that is that in the summer, ventilation is ~impossible. It's 110 degrees out there, reasonable ventilation would mean either burning out my A/C or living with temps that are far too high.

Interesting problem. Mind sharing roughly where that is?

Due to climate change, that's could be pretty much anywhere it's summer. E.g. check out the UK:

https://www.metoffice.gov.uk/about-us/press-office/news/weat...

Re: Training my sense of CO2 ppm

#23

Post by [deleted] »

Retric wrote: post #17
kadoban wrote: post #13

Earlier quoted context omitted.

My issue with that is that in the summer, ventilation is ~impossible. It's 110 degrees out there, reasonable ventilation would mean either burning out my A/C or living with temps that are far too high.

Simplest solution is a high efficiency air to air heat exchanger to let you circulate a lot of outside air. They are less efficient when dealing with high humidity, but you can have this as part of your HVAC system and never really think about it. https://en.wikipedia.org/wiki/Heat_recovery_ventilation

[deleted]

Re: Training my sense of CO2 ppm

#24

Post by moduspol »

macNchz wrote: post #12

I've had an Awair monitor for a few years and enjoy keeping a fairly close eye on the numbers, but from what I've experienced so far I'm convinced sure I'd be able to train myself to discern CO2 levels. If anything it has mostly just encouraged me to open the windows, even just for a bit, whenever possible, and to always use the kitchen exhaust fan with our gas stove (and motivated me to buy an induction range in the…

Same here. I was truly surprised at how fast the CO2 goes up with our gas stove on. The only thing worse is when we use our unvented gas logs in the fireplace.

We're switching houses next month and I'm seriously considering putting in an ERV. It's just a little tricky to explain to friends and family because it kind of makes you sound like a crazy person. But CO2 is measurable! And there is clear science about bad effects when it gets high!

Re: Training my sense of CO2 ppm

#25

Post by danans »

kadoban wrote: post #20
Retric wrote: post #17

Earlier quoted context omitted.

Simplest solution is a high efficiency air to air heat exchanger to let you circulate a lot of outside air. They are less efficient when dealing with high humidity, but you can have this as part of your HVAC system and never really think about it. https://en.wikipedia.org/wiki/Heat_recovery_ventilation

Interesting, I don't think I knew that was an option. I'll look into it, thanks. I rent right now, which means I doubt I can, but hoping to buy soonish.

If you do this (install an HRV), expect it to cost many thousands, and make sure all your duct-work is running through very well insulated spaces, or you will obviate the heat recovery part, and you will just have a very expensive ventilator.

Re: Training my sense of CO2 ppm

#26

Post by timothyb89 »

kadoban wrote: post #5

Is there any kind of CO2 scrubbing that's at all practical for home? I'm curious what the effects would be of going below ambient/outdoor levels, especially since those are rising (if slowly).

By far the simplest solution is to just crack a window. Even a modest amount of fresh air exchange is enough to offset most of the CO2 generated by the people inside.

I use a relatively small 10x11ft spare bedroom as my home office. If I close the door and window, it'll quickly climb above 1200ppm after 15-30 minutes (and set off an alarm on my sensor). It'll cross 1500ppm easily if left unchecked. HVAC helps but gets outpaced quickly if my apartment windows are all closed.

That said, keeping doors open, running HVAC normally, and cracking a small window open, even 1-2 inches and on the opposite side of my apartment, is enough to keep CO2 levels around 550ppm while sleeping and 700ppm (in occupied rooms) while awake.

Re: Training my sense of CO2 ppm

#27

Post by b112 »

saurik wrote: post #9
CoastalCoder wrote: post #7

I think the elephant in the room is calibration of the CO2 detector. When I looked into this a few years ago, I couldn't find any accuracy guaranties for CO2 meters marketed for households / greenhouses. The closest thing I could find were laboratories that could test CO2 meters in chambers with known CO2 concentrations. But IIRC the pricing for those labs was prohibitively expensive. - There were literally no guaran…

I own an Awair unit, and as far as I can tell it attempts to calibrate itself based on outside atmosphere having 400 ppm... but that value is constantly going up and is now like 415, so I figure my unit must be at least a few percent off.

I may be misunderstanding, but if you claim outside is 415 and that's that, it's wildly inaccurate.

Where you live, time of day, lay of land, all matters.

Winter (no trees or vegetation with photosynthesis), and there is naturally more local CO2.

Live deep in the country, in a forest, in the summer, when trees have loads of water and are at max output? Less CO2.

At night, more CO2, for all those trees, that greenery, is breathing and exhaling CO2, with no sun for photosynthesis.

It's variable, not static.

Re: Training my sense of CO2 ppm

#28

Post by EvanAnderson »

h2odragon wrote: post #2

people on supplemental oxygen sometimes get CO2 problems; the oxymeter shows good numbers but they're acting drunk or feeling poorly otherwise. Apparently its sneaky and cumulative; a few moments wont do much but as time goes on you get fizzier.

> ...but as time goes on you get fizzier.

While I'm fairly certain you meant "fuzzier" I can't help but thinking about bubbly blood full of dissolved CO2.

Re: Training my sense of CO2 ppm

#29

Post by bumbledraven »

b112 wrote: post #27
saurik wrote: post #9

Earlier quoted context omitted.

I own an Awair unit, and as far as I can tell it attempts to calibrate itself based on outside atmosphere having 400 ppm... but that value is constantly going up and is now like 415, so I figure my unit must be at least a few percent off.

I may be misunderstanding, but if you claim outside is 415 and that's that, it's wildly inaccurate. Where you live, time of day, lay of land, all matters. Winter (no trees or vegetation with photosynthesis), and there is naturally more local CO2. Live deep in the country, in a forest, in the summer, when trees have loads of water and are at max output? Less CO2. At night, more CO2, for all those trees, that greenery,…

Just how "wildly" inaccurate are we talking about? What should the outside CO2 readings actually look like under those conditions?

Re: Training my sense of CO2 ppm

#30

Post by h2odragon »

EvanAnderson wrote: post #28
h2odragon wrote: post #2

people on supplemental oxygen sometimes get CO2 problems; the oxymeter shows good numbers but they're acting drunk or feeling poorly otherwise. Apparently its sneaky and cumulative; a few moments wont do much but as time goes on you get fizzier.

> ...but as time goes on you get fizzier. While I'm fairly certain you meant "fuzzier" I can't help but thinking about bubbly blood full of dissolved CO2.

I think thats pretty much the case.
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