High CO2 levels at home affecting our sleep?

In this video I talk about the high CO2 levels I'm seeing in my home and discuss how I think this is affecting myself and my family's sleep.
In November 2023, I became away that the CO2 levels in my bedroom were going above recommended levels over the course of the night. I started keeping the windows open at night and it improved everyone's sleep.
I will be expanding my monitoring of the CO2 by deploying two additional sensors and moving my Airthings down into the kitchen.
The sensors I purchased from PiHut - thepihut.com/products/advance...
This breakout board is designed for RPi and Grove, but I'll be using ESPHome to read them - esphome.io/components/sensor/...
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Blog: tomasmcguinness.com
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00:00 - Start
00:23 - The problem with air tightness
02:28 - My AirThings View Plus air quality monitor
03:15 - Realising the levels were too high
04:45 - Becoming aware of very high CO2 levels
08:00 - Are the levels high through the house?
09:48 - What I'm Planning
11:10 - Wrapping Up

[@marktt]

A very worthy experiment, which I will follow with interest. Widely applicable, as homeowners over the last few years have been encouraged to stop all drafts. I am particularly interested in the possible effect of sleep…

[@r7boatguy]

Useful video. I picked up one of the Ikea AQ sensors and will be modifying it with a CO2 sensor to see how that works. We have the windows open in the spring and autumn, but in the summer it's too humid and too cold in the winter. But we do have central AC, so setting that to circulate at night is probably something I'm going to do once I have some telemetry in place.

[@cmdbill]

I have since started logging every bedroom and main room in the house for CO2 levels and it is pretty bad how much it builds up over time. Also did the ESPhome thing and 3D printed cases for the SCD40/41 with a screen and D1 mini v4. The levels of CO2 im finding out were incredibly high. Bedrooms every night were getting to 1500-2000 and we were waking up groggy and getting frequent headaches. We now wake up pretty well and not nearly the amount of headaches as before most of the time the bedrooms are around 700-800 and this seems pretty acceptable for the house we are in.

[@tomasmcguinness]

You have the same experience as us. I have to do another video on this subject as my three sensors are now ready. I have also created a simple app that both myself and my wife can use to log how we slept each night. Hopefully we can then compare the data and see if there is any correlation!

[@JohnMollaghan]

Great video!

[@chrislambe400]

The open windows trick is a royal pain in the arse in Summer at your latitude when the birds start tweeting at 4:30 in the morning or if your live rural and the tractors are speeding down the road at harvest. On the continent there are heat exchanger fans that can be built into the outside wall of each room. They blow fresh air and suck stale air at the same time and give your fresh pre-warmed air. The heat exchange rcan be turned off and fans can operate in pairs (with no heat exhanging) transporting fresh air from one side of a floor to another. This might be a good option for you. As you know the houses in Ireland and Britain have passive fresh air vents to the outside in every room with an outside wall. The cool oceanic maritime climate houses there are built differently to the very airtight houses found for example in central Europe. A lot of people just walpaper over the vents. Airtighting an Irish or British house will present you with some problems like the CO2 bedroom problem you presented. Cooker extractor fans and open fireplaces become a bit problematic when your house is very airtight. In central Europe closed fireplaces generally have dedicated pipes to the outside for fresh combustion air and the cooker extractor fans quite often won't switch on until a reed contact says the window is open or kipped to stop you from sucking smoke out of the fireplace chimney. This airtightness is why Germans religiously open all the windows twice a day to remove excess moisture (Stossluften).

[@tomasmcguinness]

We live beside a small forest, so bird noise is a year round issue!! I wasn't aware the heat exchange fans could operate in that way, so that might be a great option....intakes in the bedrooms and extract through the bathroom. Mush less invasive than a system installed in the loft. I'll certainly take a closer look at that. I'm using mechanically controlled airbricks, which I installed last year. They open and close based on humidity levels and are designed to keep the heat in my house. I installed them without really thinking about air quality. Everything I've done to my house over the past three years and reduced the flow of fresh air into my house!! I've read about Stossluften and have tried to put it practice, at least partially, opening the windows once a day for about 15 minutes.

[@MovieNutter]

The timing of this video is amazing. I purchased an esphome'able CO2 (SCD4x) sensor and been logging CO2 in the US and I was surprised that the readings were 1400-1500... Thinking it may be a bad sensor I bought a unit of Amazon and got similar readings. In the US it says 0-1000 is ok and then graduated readings above that... The fix for me was opening the windows and then things dropped quickly to 400. I am in a rental property but and I suspect that an automation and ERV/HRV would be whats needed. Be interested to see how you get on. Its interesting that over here folks are matching air tightness with the need for controlled ventilation (in and out) using ER or HRV. Relying on bathroom fan likely doesnt work as it depressurizes the house. Amazing I gave this no thought until I started measuring it... now I am thinking CO and VOCs.. yikes!

[@tomasmcguinness]

How do you find the SCD4x? There is more and more talk here in the UK about MVHR and even simple Positive Pressure Systems are growing in popularity. As we're looking to install more and more heat pumps here in the UK, there is a drive for greater airtightness to reduce heat loss. That's what I've been doing for the past few years, but like you, never thought about air quality at all! I'll share my findings once I get my CO2 sensors up and running!

[@BassPunk]

I only notice the change in CO2 when it’s above 1500ppm and thats mild. Interested to see if you get correlation data with sleep patterns. I like ionised indoor air (Blueair purifier) to sleep in, similar effect to outside after its rained 🌦️

[@jockelindh]

Hey. Thanks for sharing, really great experiment and useful conclusions. I had similar experiences when I had trouble with my ventilation shutting down at nights (now fixed) where I had CO2 up to 2000ppm in my bedroom. However, since one of your mitigations was to open the window, I do wonder how the temperature impacted your sleep quality. In general, lower temperatures does help sleep quality so I wanted to get a better understanding of your test environment. Did you have a general lower temperature in addition to the low CO2 readings?

[@tomasmcguinness]

That's an excellent comment! I hadn't considered the lower temperature as a factor - I do record that as a matter of course, so I'll be sure to include that and check for any correlation! Thanks!!!

[@TechWeb68]

Another great video Tom. I have one CO2 measuring device (Netatmo) which I shall now move around the house to get an first idea of the differing levels. Can you put a link to the sensor you selected for ESPHOME please? Also thinking of automating the ventilation system which has two speeds.

[@tomasmcguinness]

Thanks! I went for this one - thepihut.com/products/advanced-co2-sensor-breakout-board-for-raspberry-pi - as it was recommended by Trystan Lea of OpenEnergyMonitor. They are expensive, but I'm told they are *very* accurate. They will work with an RPi, but the I2C pins are exposed, so I'm hoping to use ESPHome with them. They are supported - esphome.io/components/sensor/ee895

[@chrisblunt7627]

Very interested in your monitoring and app. How you are feeling may be anecdotal rather than a definable metric, but you feel how you feel. Anything we can do to make our sleep and general wellbeing improved then I'm all for it and shall watch with interest.

[@tomasmcguinness]

It’s very possible that’s is all in my head, which I was I’ll be using my wife and kids as a control group, but I stumbled across this a few days ago - www.sciencedirect.com/science/article/pii/S0360132323011459 - I haven’t read it completely, but there seems to be a link.

[@SmithyScotland]

I tried a couple eCO2 sensors and got very random readings. Invested in 2 adafruit SCD-30 sensors which are "real co2" and they seem more accurate. Unfortunately I'm getting a reading of 3,000 in bedroom overnight when the window and door is shut.

[@BenCos2018]

the scd40 is also a good sensor tbh put it outside for a few hours and that might sort it btw

[@tomasmcguinness]

3000 is pretty high!! I haven't tried closing the door at night, so I'll be adding that to my list of tests! How are you planning on connecting up the SCD-30 sensors?

[@BenCos2018]

@@tomasmcguinness if you use esphome you can just hook them up to any esp board

[@BenCos2018]

hmm my last comment doesn't show up

[@sdfggdfg5fgdfg]

Measured with an Aranet4 the Co2 content of the two rooms I use goes up to by 470 to 300 PPM per hour. (it diminishes as the PPM rises to almost 4k) I don't keep the doors or windows open due to noise, which means during the 8-10 hours I sleep the Co2 PPM rises from 500 all the way up to 3000-4000 The rooms have no ventilation system of any kind. I'm not sure what I could improve except opening the window for twenty minutes when I wake up at 3:30AM anyway. But that still leaves me above 1kPPM for 85% of the night. (It takes just one hour to go from an open window to 1k) Should I be worried that this is impacting my sleep? I could not find any concrete resources on the matter. My sleep quality could need improvement.

[@tomasmcguinness]

At this stage, I’m still not sure. I only have anecdotal evidence. Just started recording how I feel each morning and after a few months I’ll correlate all the data together. I feel better in the mornings when the CO2 is low, but that might be just psychosomatic (I think that’s the word!!)

[@andycampbell193]

Firstly I no expert, but I suspect the CO2 levels have no impact on your health at these levels as they are still very low. I think the lack of sleep is correlation not causation. A red graph line does make you worry. Happy to be corrected 😊

[@tomasmcguinness]

You’re probably right and rhat’s what I want to find out! Anything under 1000 is deemed acceptable for workplaces, class rooms etc. so once you cross that, it’s disruptive. How disruptive, I don’t yet really understand.

[@TechWeb68]

@@tomasmcguinness please keep us informed of your conclusions🙏

[@BenCos2018]

I have a diy sensor to measure co2 you can defn notice when it goes higher tbh