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On whether changes in bedroom CO2 levels affect sleep quality

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Re: On whether changes in bedroom CO2 levels affect sleep quality

#101

Post by tossandturn »

gnat wrote: post #56
tossandturn wrote: post #31

Earlier quoted context omitted.

I have developed custom Ethylene sensors in the past for customers, and Dynament (UK) is a manufacturer that I can definitely recommend if anyone wants to do this and go down the DIY electronics route without having to dig through a bunch of Chinese products to find the "right one". https://www.dynament.com/products/gas-sensors/standard-non-e...

Cool! I worked at an ethylene-sensing IoT startup (fruit ripeness natch). What was the core sensor you used? (We were using off-the-shelf, but somewhat pricey, electrochemical sensors)

"MSH-P/HC/NC/5/V/P/0 - 3% Volume Ethylene = 0.4V - 2.4V"

We built that into a custom SS body with a Delrin mounting insert, and ran the serial connections to a custom board that interfaced with up to 8x sensor locations (in conjunction with some other sensor elements). The elements were ~US$200/ea ~4.5 years ago.

These are fancy interpolated IR absorption sensors internally, so any gases of similar concentrations could throw off the readings; depends on the environment. Would be BEST to calibrate to local atmosphere conditions of the installation, but that's not really something you can sell. :P

Re: On whether changes in bedroom CO2 levels affect sleep quality

#102

Post by s0rce »

treis wrote: post #97
SketchySeaBeast wrote: post #87

Earlier quoted context omitted.

> but it allows us to run the furnace less at night (heat from the lights) Dear God, what's your power bill? There's no way a LED lights heat is as efficient as just using the furnace. edit: I meant cheap, not efficient.

Theres no difference in heating efficiency for any source. Heat is heat and it doesn't really matter if it's generated from a heating element in a furnace or an LED light. And with the light you're at least getting dual use out of it. If they have a gas furnace it might be different but that would also depend on how their electricity is generated.

except a heat pump which is far more efficient

Re: On whether changes in bedroom CO2 levels affect sleep quality

#103

Post by drpgq »

Robotbeat wrote: post #74
clairity wrote: post #22

Earlier quoted context omitted.

i’ve noticed this casually as well. i bought an airthings wave plus [0] a few months ago and the co2 and total voc readings seem pretty (but not perfectly) correlated. i live in a drafty pre-war building and my co2 peaks at around 1500-1600 ppm at night with doors and windows closed. it troughs at around 500 during the day when i have the doors and windows open (~400 is ambient from what i understand). tvocs typicall…

413ppm is now ambient. Goes up higher every year (with a small amount of seasonal variation). By 2100, we may be at 800ppm if we continue and/or accelerate fossil burning (4 degrees C trajectory). https://www.co2.earth/2100-projections Already a middling stuffy room, and would increase indoor levels 400ppm over today.

I wonder at what point will people have active systems to lower their CO2 below ambient in their homes.

Re: On whether changes in bedroom CO2 levels affect sleep quality

#104

Post by willsr »

tossandturn wrote: post #31
bizzleDawg wrote: post #16

I've worked on environmental sensing iot projects and have seen the cost of co2 sensors. Almost all the cheap ones are VOC sensors which infer a co2 level by assuming the VOC output is from humans (rather than paint for example). Given the cost of the device I would be amazed if it wasn't a VOC based sensor. The cheapest CO2 sensors I've seen are well over $250, even in bulk. CO2 is quite innert, so it requires very…

I have developed custom Ethylene sensors in the past for customers, and Dynament (UK) is a manufacturer that I can definitely recommend if anyone wants to do this and go down the DIY electronics route without having to dig through a bunch of Chinese products to find the "right one". https://www.dynament.com/products/gas-sensors/standard-non-e...

I remember looking into this years ago, and the prices were in the $100-$200 range for low volumes. Was this your experience?

Re: On whether changes in bedroom CO2 levels affect sleep quality

#105

Post by freetime2 »

SketchySeaBeast wrote: post #95
cl0ckt0wer wrote: post #94

Earlier quoted context omitted.

Assuming the furnace is electric too, they should both be the same efficiency, since 100% of the power is being eventually turned into heat, unless the light from the LEDs are going outside.

I never considered an electric furnace - I come from a land of ice and snow and the only real option is natural gas.

I live in a land of ice and snow and we rely entirely on mini-split heat pumps in the winter [1]. Admittedly they do lose efficiency quickly when temps drop well below freezing, but they work well enough here.

I have also seen some pretty cool looking "passive" houses that, due to excellent insulation, are able to heat the entire house with a 3kW furnace [2]. And these are in very cold locations (e.g. Alberta, Canada).

Electric heating is the future!

[1] https://learn.compactappliance.com/mini-split-heat-pumps/

[2] https://www.youtube.com/watch?v=AlA4_lesrU4

Re: On whether changes in bedroom CO2 levels affect sleep quality

#106

Post by Symmetry »

greenleaf2 wrote: post #54

There's one big problem with this entire idea of co2 levels affecting sleep quality or humans in general: Even though there are cognitive effects of CO2, most often the CO2 levels in indoor rooms are simply a sign of low oxygen levels. In fact, there should be an inverse relationship between CO2 and oxygen in rooms. So an experiments would need to take this into account and supply pure oxygen to make up for the oxyge…

That's intuitively appealing but when you look at the numbers it's almost certainly false. When CO2 goes from 400 ppm to 1000 ppm then oxygen will go from 21000 ppm to 20400 ppm, a 3% drop which isn't going to be enough to change anything.

Re: On whether changes in bedroom CO2 levels affect sleep quality

#107

Post by dagoat »

paradoxparalax wrote: post #67
DocG wrote: post #29

I was lucky to get my hands on 5 proper co2 sensors from university, while I was teaching and working. So plenty of test places. What I found: -Just a couple of hours in a office, without ventilation spikes the co2 enough to make everyone dizzy and tired by the end of the day. Keeping eye on the meter and ventilating properly, increased everyones productivity and people werent so tired by the end of the day. - Classr…

There was an NBA coach who use to obligate his players to sleep with at list some inches/centimeters of air access in their windows hotel rooms the night before playing an important game/match. Don't remember what Team.

Surely he'd have to tuck them in at night to verify that...

Re: On whether changes in bedroom CO2 levels affect sleep quality

#108

Post by JauntyHatAngle »

DocG wrote: post #29

I was lucky to get my hands on 5 proper co2 sensors from university, while I was teaching and working. So plenty of test places. What I found: -Just a couple of hours in a office, without ventilation spikes the co2 enough to make everyone dizzy and tired by the end of the day. Keeping eye on the meter and ventilating properly, increased everyones productivity and people werent so tired by the end of the day. - Classr…

My friend studied Interior Architectural Design, one of his professors there started one lecture a year by getting the CO2 sensors, placing them around the lecture hall, showing the readings at the start of the lecture, closing the doors and then after the hour long lecture showing the readings.

During the lecture he mentioned the figures for CO2 concentration that led to symptoms, e.g. dizziness, sleepiness etc.

The reading at the end of the lecture showed that it was over the recommended limit, and well beyond the threshold that causes people to get sleepy and lose concentration. (I believe it was less than 400ppm at the start and thousands ppm afterwards?)

A simple demonstration using an older building crammed full of students in a closed space, but it was apparently quite impactful in showing the students how there are a lot of features of interior design architecture that aren't really addressed and are only coming to the fore recently.

Re: On whether changes in bedroom CO2 levels affect sleep quality

#109

Post by freetime2 »

In Japan, the building code requires every room to have an air vent [1]. Initially I was skeptical of them and was looking to close them to save on heating costs in the winter. But after doing a little research, I decided they are probably best left open to reduce condensation and mold growth.

Now I'm curious how effective they are at keeping down CO2 levels at night. I would like to try this experiment in my house.

[1] https://resources.realestate.co.jp/living/japanese-apartment...

Re: On whether changes in bedroom CO2 levels affect sleep quality

#110

Post by marijnz »

Previous company I worked for had dashboards and Slack integration for the CO2 levels on all floors. There's a blogpost on how it was done (Raspberry PI's, CO2 sensors and open-source python script): https://blog.wooga.com/woogas-office-weather-wow-67e24a5338
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