CO2 in bedroom affects sleep, claims Danish

https://medicalxpress.com/news/2023-05-reveals-poor-bedroom-air-quality.html

sample quote

If ventilation keeps CO2 from persons sleeping in a bedroom below 750 ppm, then the air quality in the room is so good that it does not affect sleep quality. If CO2 exceeds 2,600 ppm, the air quality is so poor that it affects sleep quality to such an extent that cognitive abilities are affected the next day; this may also be the case at lower CO2 concentrations.

CO2 is used as an indicator of how good the ventilation is in rooms where there are people. Indoor CO2 is mainly released by humans due to the metabolic processes of the body. The concentration is measured in mg/m3 or in ppm (ppm, parts per million, refers to the number of carbon dioxide molecules per million molecules of dry air).

Below 750 ppm: Adequate ventilation—no negative effect on sleep quality. This will be a typical measurement for a well-ventilated bedroom.

Between 750 ppm and 1150 ppm: Possibly insufficient ventilation—in some cases, sleep quality may be adversely affected.

Above 1150 ppm: Insufficient ventilation—sleep quality will be adversely affected. CO2 levels that are higher than 1150 ppm will typically occur in bedrooms that are not fitted with a ventilation system and where windows and doors are closed.

Above 2600 ppm: Insufficient ventilation—both sleep quality and next-day performance are adversely affected.

end quote

I dont know about any of that, but I did order a my pillow and now I crash and just wake up 8 hours later, no tossing and turning etc. It works! (use the t-shirt chart to get the right pillow)

What does a pastry know about sleep?

I have clean filtered humidified air every night with my cpap.

Sure, me too, but I'll bet yours doesn't filter out the CO2 either :whistling

This is as odd as a two holed doughnut.

I have a travel size MyPillow and consider it the best pillow I have ever slept with.
It does machine wash and dry without issue.

I cannot help sleeping on my stomach which the Doctors correctly say causes problems.

I have lots of experience from swimming in being in “extreme oxygen debt - high CO2” blood level and body conditions.
At one time I could easily hold my breath for more than 2 minutes, and swim at 100% muscle effort for 22 to 50 seconds without taking a breath.

I have been trapped in the “undertow” of white water rapids for what seemed like “forever” even with a flotation vest trying to help me back to the surface.

I am very aware of the one lone coal miner who survived out of 12 in the low oxygen, high carbon monoxide air in a coal mine which MDs speculate was because he ate fish 3 times per week and had more Omega-3 fat in his body tissues than his 11 crew members.

https://abcnews.go.com/US/story?id=1469171

The “sleep apnea” condition puts people into high CO2/ low oxygen conditions for long periods.
Several close family members have used these machines for years.

Around 1991 I was told I needed to lose 40 lbs or start using a CPAP machine.
I was able to loose the weight relatively easily by walking 2 hours in the morning and 2 hours in late afternoon.
I used the official US Army method of walking 3 miles in 50 minutes, then resting/drinking/ peeing for 10 minutes, then walking 3 miles in 50 minutes, etc.

The engineer in me calculated that my “fuel economy” at 4 mph was 40 miles on one pound of Lard (fat).
Lard is pretty close to Diesel fuel, so that works out to roughly 240 MPG at 4 mph walking speed.

Since nearly everyone has 5 lbs of body fat,
the realization that we could walk 1200 miles with just water is rather stunning to think about.

Birds like Pigeons may have “fuel economy” of 1000 MPG at 30 mph which is also thought provoking, although they may use favoring tail winds.

Our thermostat is programmed to run the fan a minute of 20 minutes over the course of an hour, regardless of the unit calling for heat/AC
Helps help the air fresh during those seasons when the house self.maintains temp.

The people living on the eastern seaboard get 20% cleaner air than those living on the west coast according to pollution studies by NASA, Asia pollutes the air, the U.S. cleans it up

That is a good idea.

I have personally struggled trying to keep all the rooms in a 2 story house in the same comfort zone, temperature and humidity wise.

I have also “been forced to discover”
that air mover fan motors need yearly lubrication if they have sleeve bearings
and that the original USA made electrical contactor and its associated control relay for the motor can last 20+ years,
but the Chinese replacements can fail in months.

I would like to figure out an inexpensive way for the always-on fans of HEPA filter units to equalize
temperatures, freshness,
and the latest medical “buzzword” - 2.5 micrometer air pollution particles
between upstairs and downstairs rooms
to relieve some of the stop/starts on the expensive blower motor and its “gotta use a puller” squirrel cage fan.

I am leaning toward installing duct pipes between stacked upstairs/downstairs bathrooms,
or just selling this house and living on the beach in a one story house in Florida where hurricanes surpass all ventilation levels.

Actually that's not new, and it's not a "buzzword" either. A brief lecture:

My late toxicology professor used to say back in the 90's about lab air pollution experiments, "Rats can't inhale rocks". In other words, really large particles don't make it into the nose. Particles big enough to stay in the airstream are trapped in the mucus of the upper airways starting at the nose, and usually swallowed or ejected. Really tiny particles (less than 0.5 um) go in and out of the lungs with the air. But those around 2.5 um get sucked in and stick in the alveoli, the microscopic lung sacs where the actual exchange of oxygen and CO2 takes place.

That is why that particular size is important. Especially if they are carcinogenic materials (chemical or alpha-emitting radioactive) that stay in the lung for life and keep building up with exposure over time.

My furnace fan runs 24/7, has for years, I like the air and the white noise. Just have to swap the filter more often.

I am interested -2.5 micrometer particle science.
Buzzword to me means “suddenly very much in abstracts” not utterly false.

I have been involved in particle air pollution since 1975 when I was required by law to take a course in “Black Lung” disease due to the new regs in the 1968 Mine Safety and Health law. I decided then, at my Grandfather’s urging, to start wearing a N95 masks/respirators. I have now worn N95s countless hours. My first job underground was as “Curtain Man & Cable Puller” which puts you in the thickest dust. It was known then that Coal has Uranium and Thorium naturally in it., plus Silica varieties, which can cause lung cancer. Some coal seams have layers of volcanic ash mixed in.

In school I had Professors who were involved in the local problem of “Brown Lung” from cotton dust in the many textile mills of the Carolinas, and many mill workers also smoked the cigarettes that were turned out by the Billions in the Durham cigarette factories.

In 1978 I had to take British National Coal Board dust protection and abatement training too.
The NCB is correctly proud that they pioneered mine dust health.
They call it Pneumoconiosis rather than “Black Lung.”
I asked my instructor why the UK standard for dust was 4 milligrams per cubic meter, whereas in the USA the legal limit was 2 milligrams per cubic meter.
He laughed, then walked over to stand over me where I was sitting, and replied loudly in a room of several dozen Newcastle and Yorkshire area miners -
“I was there in the USA as an expert witness. Your Senator Ted Kennedy said, if the British say 4 prevents Black Lung, then I am gonna write our law at 2. I guess Ol’ Teddie was in a hurry, musta had another beach date with a hot teenager.” This got a big laugh.

If really small particles can go directly from air through thin tissue to blood in the lungs, and then can cause diseases, including brain diseases such as dementia where these tiny particles must also pass through the blood-brain barrier, that is scary.

Air pollution is super bad in China and Chinese researchers suspect it does happen.

A huge number of people cook inside over dung fires, or wet, high ash, waste coal fires that don’t have efficient combustion,
and that air pollution is perhaps the worst I have witnessed.

In the 1970s the National Coal Board in the UK designed highly scientific fireplaces and furnaces under the “Real Fire” trade name.
Those were actually smokeless. Very impressive. All gone now.

That's an impressive TL;DR lecture despite what appears to be a non-medical CV (how exactly are you "involved" in air pollution since your black lung course in 1975?), but also entirely irrelevant to the issue the OP raised.

What would be an inexpensive way of measuring the CO2 in a room?

I breath Co3 on May the 4th be with you...

many of the Amazon sold meters that used to display only time, temperature and humidity
now have CO2 and PM 2.5

some reviews

https://smartairfilters.com/en/blog/best-pm2-5-air-quality-monitors-2023/

The little belt worn battery powered air pumps that catch dust particles in a filter that is then mailed to a certified laboratory are very very expensive and have been around since 1970.
Coal miners hate them for their noise and weight and they have been “accidently” dropped in mud holes, zapped with arc welders, or run over by caterpillar tracked 30 ton mining machines.
Miners also routinely place them in the clean “intake air” tunnel where there is little dust.
By law coal dust must be diluted by at least an equal amount of finely ground up, specially selected, limestone dust.
Inside of coal mines are white colored because of the “rock dusting.”

You can get stand alone HEPA filter setups for any room. I got one for the bedroom for the wife, she had allergies, it helped her. Myself? I just run the furnace fan on low running the house air thru it's HEPA filter.

Mainland China estimates high PM 2.5 pollution killing 1,400,000 of its citizens per year

https://medicalxpress.com/news/2023-05-highlights-health-hazards-air-pollution.html

I have never bothered to measure the CO2 levels in my house, but I have made sure to have fresh air from outside.
I don't have a thermostat or ventilation in the bedroom, but the ritual of cracking open a window, even just a touch in winter, is for me an essential part of creating a suitable environment for sleep.

But besides clean air, I've also invested some money in creating a comfortable sleeping environment. I've been sleeping on a Pluto pillow, which has truly upped my comfort, and a Leesa Studio mattress, which is great for all sleep positions.

To top it all, I've gone for minimal lighting, and my bedroom is as tech-free as possible. No TV, no laptops. Just a simple digital clock.

I had never heard of a Pluto Pillow - looks interesting.

I am presently sleeping with the small size “Travel Pillow” made by MyPillow
which has been the best I have tried.

I recently had to take 14 days of the strong antibiotic Clindamycin for a tooth infection
and have not been sleeping as good,
perhaps because the “broad spectrum” antibiotic wiped out some of the “good bugs in the gut”.

Good and bad gut bugs have certainly been in the medical news.

Since year 1906 medical researchers have beeb trying unsuccessfully to transfer Alzheimer’s disease
by taking some kind of sample from a human
and then infecting a animal with it to give the animal Alzheimers disease,
and here is how they finally successfully did it:

https://www.news-medical.net/news/20231017/Gut-microbiota-linked-to-Alzheimers-disease.aspx

I have not pulled the trigger on buying the new cheaper CO2 and PM 2.5 um meters for home use
because the Amazon reviews have been so critical.

If only they would sell a gas meter that would do double duty - home air measurement and engine tailpipe exhaust analysis?