Ask HN: Do you measure and/or mitigate CO2 in your living space?

I recently started measuring CO2, Radon, PM (particulate matter) 1.0, PM 2.5, VOC, humidity, temperature, and air pressure with the Airthings Wave connected device.<p>I have learned a lot while using it for a couple weeks. First, making a fire in your fireplace is great for ambiance but drags air quality down substantially. It eats up oxygen a lot and make the CO2 increase sharply. It also causes very high spikes in particulate matter (both 1.0 and 2.5 micron) from putting the burned byproducts into the air.<p>I also started improving the energy efficiency of our heating system by fixing spots in the house where cold air comes in. While this results in less energy used to heat the home, it causes CO2 to increase because there isn’t anymore large holes to bring fresh air in. This device helped me learn that CO2 is and energy efficiency are circular problems. The tighter my house is, the more I need to focus on ventilation - exhaust out and fresh air in. It sounds complicated but for me it just means opening windows throughout the house for about 15-30 minutes per day. That alone makes a major difference on everything - Radon, PM 2.5, PM 1.0, CO2, etc.<p>Lastly just want to mention that it’s amazing to me how fast CO2 levels can rise with just my husband and I in our living room watching a movie. Good ventilation is something I definitely recommend everyone start measuring and working on.

HVAC Controls tech here;<p>Commercial buildings have all sorts of rules under Ashrae in the US. Generally in commercial there is a minimum air exchange rate for occupied space. Pre covid it was being constricted for &quot;green&quot; energy initiatives in the name of energy and $$ savings. That restriction was allowed to be really clamped down on (more savings) if certain conditions were met like CO2 monitoring or people counters, both more tightly targeting how much fresh air people actually need and minimizing waste in conditioning outside air that isn&#x27;t necessary. Post covid a lot of that got thrown out, commercial buildings are now generally over shooting OA exchange in the name of not turning these spaces into germ breeding grounds.<p>None of this really exists in the residential sector, but maybe it should. Homes in even the recent past are &quot;leaky&quot; enough to get enough outside air exchange for the low occupancy rates without actively conditioning and bringing in outside air. Some modern energy efficient homes that are wrapped and sealed extremely well might pose an issue to this.<p>By all means get a decent sensor that reads CO2, CO, PM1, PM2.5, and VOC. Radon if you are in a risk area. Your regular thermostat probably already gets you temp and humidity. It needs to have some way to do long term data logging, five or ten minute sample rate for a year for example. You really want to see how things are different across seasons.<p>With that data in hand there are plenty of things you can do if you need to introduce more OA to occupied spaces. Generally there are heat exchangers that can be dedicated to that sort of thing. Or a simple motorized damper opening up a small filtered OA duct on the intake side of the air handling unit. Ideally those devices would only be activated on unacceptably high bad air quality readings.

Returning to college teaching mid-pandemic, I bought an SAF Aranet4 Home CO2 meter for measuring my classrooms. It mostly lives in my apartment, waiting to alert me in case I didn&#x27;t realized I was using my gas range.<p>There&#x27;s good evidence predating the pandemic that sufficient air exchange can nearly eliminate respiratory disease transmission. Just as they learned long ago in London that one could eliminate cholera by not drinking sewage water, we understand that the air quality and rate of exchange of indoor air should approximate that of outdoor air. We&#x27;re however too cheap to do anything about this; it will take more deadly pandemics to drive the needed infrastructure changes.<p>Do you wince at the idea of people in London drinking sewage water? Those ignorant savages? Yeah, that&#x27;s how people in the future will look back at us, getting colds and worse all the time in indoor air cesspools.<p>As we breath out CO2, it makes a great way to measure whether we&#x27;re changing the air in a room fast enough to keep up with occupant breathing. Wilderness air passed 400ppm as part of global warming. My Manhattan apartment is above the Henry Hudson Parkway, and I can tell the time of day and day of week from the effect of traffic on my CO2 meter. I&#x27;m lucky to ever get below 450ppm.<p>The Aranet works far better than a $30 meter at the measurements a $30 meter will make, such as humidity. By appearance and build quality it&#x27;s in a different league. CO2 is a bonus.

Yes, absolutely. Probably not popular with the HN crowd, but I use the &quot;consumer-friendly&quot; (cloud-connected) Awair for both CO2 and PM2.5.<p>And I&#x27;ve been absolutely gobsmacked to discover just how much my mental clarity and energy are linked to CO2 levels. Above 1200 I&#x27;m just kind of out of it -- I function but my thinking is like half-speed, 700-1200 is much better but still not optimal, whereas basically 600 and below I&#x27;ve got the energy to do anything. And I&#x27;m still &quot;shocked&quot; at how this is a recent discovery, and not common knowledge at all.<p>So now, I keep a single window open a crack all year round to keep levels below 600, and actually change how far it&#x27;s open as needed depending on what the sensor says. On a room-temperature still day I might actually need it wide open because the air barely enters, while on a freezing windy winter day it only needs to be a couple millimeters open. Interestingly, my electric bill hasn&#x27;t gone up by any obviously noticeable amount -- I think because so much of heating&#x2F;cooling is &quot;stored&quot; in the walls&#x2F;floor&#x2F;furniture&#x2F;etc., not just the air.<p>I haven&#x27;t moved away from a gas stove because I rent instead of own, but it&#x27;s shocking how quickly CO2 and PM2.5 rise, so I keep my vent hood blowing full blast while cooking, and also open multiple windows. I don&#x27;t close the windows until both levels have returned to normal.

I have several Airthings Wave connected devices, and I also purchased and installed a Panasonic ERV[0], which I have hooked into my HVAC system. Opening windows several times throughout the day was how I used to control the Co2, but in the winter and summer it became a huge hassle with the temp&#x2F;humidity changes in the house, but with the ERV running 24&#x2F;7 I will see an empty room drop to 400 ppm fairly quickly after people leave it (Airthings has an app). Generally rooms with people in them hover around 600-800 ppm with the ERV running. The ventilator will keep the humidity&#x2F;temp levels pretty consistent because it has this cross capillary core that it runs the air through, but I do need a good few humidifiers running in the winter. The ERV also has the benefit of allowing you to control the air pressure in the house, which is useful for radon, as I was unable to get a good radon pump installed without destroying my downstairs (I live in a raised ranch where the &quot;basement&quot; is the first floor). With the positive pressure in my house + constant ventilation I never see the radon levels generally go above .5.<p>[0]: <a href="https:&#x2F;&#x2F;na.panasonic.com&#x2F;us&#x2F;home-and-building-solutions&#x2F;ventilation-indoor-air-quality&#x2F;energy-recovery-ventilators&#x2F;intelli-balancetm-100-balanced-air-solution-cold-climate-erv-50-100-cfm" rel="nofollow">https:&#x2F;&#x2F;na.panasonic.com&#x2F;us&#x2F;home-and-building-solutions&#x2F;vent...</a>

In my country it is common to start your day by opening all windows for 5-10 minutes. It’s done several times a day sometimes.<p>I worried about CO2 and general air quality in the office, particularly at those moments when coming back for lunch and noticing a “loaded environment” for lack or a better word. Not a problem anymore thanks to remote work :D

Running an Awair in the kitchen while cooking is enlightening. I run the stove vent fan to mitigate.<p>There is no good solution for substantially mitigating CO2 in a living space other than ventilation. I also have an AlgenAir, and I love the business, but it can&#x27;t on its own consume enough CO2 to compete with human production in a closed area. 100 devices- 2000+ plants equivalent- is what the CO2 absorption math says would be needed.

Yes I measure.<p>Since I couldn&#x27;t find an affordable consumer device, I build one myself. Levels in my living room never really exceed acceptable levels. My house is not airtight and constantly mechanically ventilated.<p>They have to pry my gas stove from my cold, dead hands. I refuse to accept indoor air quality deteriorates that much when using a proper hood (that means turning it on before igniting your stove).

I use a raspberry pi with both a SCD30 and MZ-14A, logging to influxdb and visualised with Grafana.<p>The SCD30 generally seems to report higher CO2 levels than the MZ-14A. I believe it is probably more accurate because of it&#x27;s calibration technique.<p>Both are NDIR based sensors.<p>* <a href="https:&#x2F;&#x2F;sensirion.com&#x2F;products&#x2F;catalog&#x2F;SCD30&#x2F;" rel="nofollow">https:&#x2F;&#x2F;sensirion.com&#x2F;products&#x2F;catalog&#x2F;SCD30&#x2F;</a><p>* <a href="https:&#x2F;&#x2F;www.winsen-sensor.com&#x2F;d&#x2F;files&#x2F;MH-Z14A.pdf" rel="nofollow">https:&#x2F;&#x2F;www.winsen-sensor.com&#x2F;d&#x2F;files&#x2F;MH-Z14A.pdf</a>

I do. I just got started because it looked like a fun project to build, I went with the Airgradient DIY solution[0]. At first I used a combination of Prometheus and Grafana, then I integrated the solution with an MQTT server and Home Assistant[1] instead.<p>I live in a duplex, which means there&#x27;s _a lot_ of air volume and mostly just me, so CO2 levels don&#x27;t skyrocket and won&#x27;t even reach 1000ppm after the whole day. I usually blast the windows open for a few minutes first thing in the morning and that does the trick, bringing levels down to ~500ppm.<p>What&#x27;s worth mentioning is the massive temperature difference in between the top and the bottom floor, which is from 3 to 5 degrees Celsius higher upstairs. CO2 is also higher upstairs, about 150ppm, and P2.5 is usually higher downstairs (do they fall to the ground?)<p>I&#x27;m taking one of the sensors to my parent&#x27;s this week, since they use a closed log burner to heat the house and I&#x27;m curious what the levels are going to be.<p>Last anecdotal point, I was fitting a Bosch Athlete upright vacuum cleaner with new VTC6 batteries for extended battery life and increased suction power this weekend, which requires a lot of soldering iron and tin, and I was amazed at how the PM2.5 would go crypto-style _to the Moon_<p>[0] <a href="https:&#x2F;&#x2F;www.airgradient.com&#x2F;open-airgradient&#x2F;instructions&#x2F;diy&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.airgradient.com&#x2F;open-airgradient&#x2F;instructions&#x2F;di...</a><p>[1] <a href="https:&#x2F;&#x2F;github.com&#x2F;nsbk&#x2F;airgradient_mqtt" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;nsbk&#x2F;airgradient_mqtt</a>

I stopped using my gas stove about 3 years ago, after it seemed to be causing histamine problems. It was only later that read that this was a known problem, rather than only a bizarre correlation I noticed. I now use an electric air fryer toaster oven, which causes only small particle increases.<p>I recently got a semi-credible-looking non-IoT air quality monitor (CO2, TVOC, PM1, PM2.5, temp, humidity). I can&#x27;t say how good the self-calibration is, but when the readings vary up&#x2F;down usually seems to make a lot of sense.<p>For CO2 (and other air quality concerns in this problematic old student apartment, in a crazy university neighborhood housing market), I almost always have a couple windows cracked open.<p>And, if I haven&#x27;t had a central window open wide for awhile, I&#x27;ll try a large air exchange with outside, by opening many windows wide for a few minutes.

&gt; Do you measure<p>No.<p>&gt; mitigate CO2 in your living space?<p>I open the window occasionally and when they are not open the are pretty draughty windows.

We picked up the Aranet 4. Things were fine until we replaced our windows with fancy new ones. Our air quality plummeted, CO2 &gt; 2200.<p>We got a new air exchanger installed, connected to our existing forced air hvac system. It runs at a low speed 24x7, which keeps things at a reasonable level.<p>It has a few settings like: continuous, 20 minutes&#x2F;hour, 40 minutes&#x2F;hour, and &quot;humidity control&quot;. Nothing for CO2 control though. I have aspirations to hack the control module and make it care about CO2, but I&#x27;ve also got two kids and a startup so who knows how long that will spend in the backlog.

I used to monitor CO2 in the house with Awair units, specifically those because it allegedly interacted with my Ecobee AC control. So I could say if the levels were rising, force the fan on to push fresh air around, although I&#x27;m not sure I ever got it working correctly.<p>It&#x27;s a big problem for me, as living in Florida basically means the AC runs almost year round. In the colder months we open the windows as much as we can to let the levels drop, but from spring through autumn it&#x27;s just too hot to keep them open, as it just pushes the AC harder to cool more and more, while also increasing the humidity.<p>We definitely started getting better nights sleep once we had either the windows open, or the door to the bedroom open. I also rarely shut the door to my office as I was getting so sleepy at my desk during the afternoons.<p>I have no real solution for the hot months anymore, as Awair has basically abandoned the units I was using. I&#x27;ve just had some Zigbee air quality monitors arrive that I ordered on Aliexpress, but I&#x27;m skeptical at how accurate they&#x27;ll be. Infact I&#x27;m skeptical at how accurate <i>any</i> of them are after I did some research into building my own and adding some sensors to an ESP32.<p>Going to have to try and come up with some HomeAssistant automation task with the Zigbee sensors and Ecobee to push fresh air through the house.

I did that in the last weeks. I live in Germany and we have a flat that is not very modern but has reasonable insulation. What I learned that under these conditions, with two people in a 30 square meters room, CO2 rises so quickly that one has to do intermittent, full ventilation (about 3 to 5 minutes, in Germany it&#x27;s called &quot;Stosslüften&quot;) for about every hour, to keep CO2 levels below 1500 ppm. During the night in a smaller room, one can get easily levels of 3000 ppm. That&#x27;s not dangerous, but it is not recommended for places where people have to work in a concentrated manner, like offices, or schools, for example. The recommended limit by the federal office for environment is 1000 ppm.<p>And that build-up of the stuff is a big difference to where we were living before (Edinburgh) where that kind of ventilation was basically unnecessary because no window closed that hermetical (well we lived in one of those wonderful 140 year-old houses in New Town).<p>In the end, with good insulation, it becomes increasingly important to have some active ventilation - it is also more economical, because it saves on heating. And that is in fact becoming more widespread with new family houses.

No.<p>(Chiming in to diminish sample bias.)

I use an Aranet4 in the living room. Mechanical ventilation in most homes in NL allows configuring a precise flow rate in cubic meters so I&#x27;ve found the breakpoint to keep it &lt; 1000 ppm.<p>I took it to the office one day and it measured 2000 ppm. It turned out one of the motors that brings in fresh air in the ventilation system had failed, I wonder if it would have been noticed without the meter. It&#x27;s a great little device.

I have a Nentatmo CO2 monitor in my apartment. I discovered that during training on a stationary bike, the CO2-levels exceed 1000ppm. Probably due to increased breathing. Therefore I increase the ventilation when I do a workout

I&#x27;m using a relatively cheap (68EUR) TFA Dostmann AirControl Mini CO2 Meter (also available from different brands as well) based on ZyAura platform. I soldered a connector to connect it to an ESP8266 board flashed with ESPHome software [1] and then send measurements to the Home Assistant instance.<p>This system works well, the sensor is on my desk, the CO2 drops quickly below 600 ppm when the window is open, but then immediately returns to above 800 ppm shortly after the window is closed. For example, I currently have 982 ppm.<p>At night, with 2 people sleeping in the room, the level often rises to 2500 ppm. So even though I ventilate the house much more often than I did before I bought the sensor, it&#x27;s still not enough to maintain healthy CO2 levels, and with the current energy prices and cold weather, I don&#x27;t know what else I can do, I have no space to install heat recovery ventilation.<p>1: <a href="https:&#x2F;&#x2F;esphome.io&#x2F;components&#x2F;sensor&#x2F;zyaura.html" rel="nofollow">https:&#x2F;&#x2F;esphome.io&#x2F;components&#x2F;sensor&#x2F;zyaura.html</a>

Modern homes are so well insulated that it sometimes happens that a family will host a big holiday party, use their fireplace for the first time, and then get dinner started shortly thereafter; the first time their nearly commercial grade overhead hood fires up, hot embers will be blown across the floor of the room with the fireplace.<p>(Or, those homes correctly have a &quot;make up air&quot; duct installed, which resolves this scenario)<p>We recently rebuilt the wall that houses our hood for our propane kitchen range. It&#x27;s 4 inches, and I asked how difficult it would be to move to a 6 inch duct, since it&#x27;s far more volume of air to be moved. Of course, the answer was a logistical difficulty and out of budget.<p>On particularly damp days in the winter here in New Hampshire, if someone accidentally leaves a bathroom fan running, and perhaps the kitchen hood, it can be nearly impossible to get a wood stove fire going. So although these electrical systems are not drawing what seems like a lot of air, they have practical effects on unrelated systems.

On the topic of gas stoves, it is mindblowing that building codes (even in CA) allow for stove vents that do not exhaust outside the house.

We provide a commercial and a popular open-hardware air quality monitor [1] that includes CO2 as well as PM 2.5, VOCs, NOx, humidity and temperature. I am talking everyday with people around the world about why they want to measure air quality and the parameters they are interested in.<p>On CO2, we observe mostly three different use cases:<p>CO2 as an approximator of Covid infection risks: With the possibility to use CO2 levels as an aproximator of aersols with potential virus load, CO2 became quite popular as a measure about how effective the ventilation works.<p>CO2 as an indicator of cognitive performance: There are a number of studies, e.g. [2] showing a clear link between high CO2 levels and impaired cognitive performance. I am seeing more and more people that especially want to measure CO2 levels in order to keep them low and have a better working environment.<p>CO2 as an indicator of ventilation rates: Without ventilation, indoor pollutants e.g. harmful gases from furniture, colors, building materials etc. will increase. Some of them can be measured as TVOCs but not all of them. Low CO2 values indicate a high rate of air exchanges and these typically flush out these indoor pollutants. Ideally the HVAC system uses HEPA and carbon filter for the fresh air intake to ensure that the air coming in is clean. In climate zones with a high differential between indoor and outdoor temperature, heat exchangers should then be used.<p>If you measure more than CO2, but also PM and Temperature and you have the ability to control your ventilation rates (either by manually opening windows or by a demand controlled HVAC system) you can see and optimize potential tradeoffs, e.g. cooling or heating energy is wasted by increasing fresh air ventilation rates or opening windows will bring down CO2 but increase PM if you live in a polluted area.<p>Regarding the OPs question on moving away from gas stores. Here the new TVOC sensor from Sensirion SGP41 [3], that can be uses in our open-source open-hardware air quality monitor [1], is able to measure NOx and can be a good indicator if your stove emits fumes into the living area.<p>[1] <a href="https:&#x2F;&#x2F;www.airgradient.com&#x2F;open-airgradient&#x2F;kits&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.airgradient.com&#x2F;open-airgradient&#x2F;kits&#x2F;</a><p>[2] <a href="https:&#x2F;&#x2F;dash.harvard.edu&#x2F;handle&#x2F;1&#x2F;27662232" rel="nofollow">https:&#x2F;&#x2F;dash.harvard.edu&#x2F;handle&#x2F;1&#x2F;27662232</a><p>[3] <a href="https:&#x2F;&#x2F;sensirion.com&#x2F;products&#x2F;catalog&#x2F;SGP41&#x2F;" rel="nofollow">https:&#x2F;&#x2F;sensirion.com&#x2F;products&#x2F;catalog&#x2F;SGP41&#x2F;</a>

I run an Aranet4, it&#x27;s set to alert if the co2 goes over 900ppm which is where I notice a dip in cognition or at least wakefulness.<p>I use its API to connect to it once a day and download the last 24hrs of logs (it stores 14 days worth on the device).<p>It&#x27;s expensive - but it&#x27;s really the best there is IMO.<p>I try to open a window on either side of the house when the co2 gets over about 750~

I don’t measure or actively mitigate carbon dioxide; however, we do run particulate filters 24&#x2F;7. No central air, but we use a large window fan to pull fresh air into the house during the summer months.<p>Winter is the real concern. Not much opportunity to air out the house when the temp is consistently below 20 degrees Fahrenheit.<p>I supposed I should look into a heat exchanger.

We borrowed a sensor for a few weeks and measured different rooms. The readings are especially high when we invite people. (We cook electric , and I think the stove has little to do with high CO2 in a living space.)<p>The conclusion is that we need to ventilate more. Especially in the bedroom. Sometimes it’s hard to find a good balance between ventilation and heating.

Yes, but I mostly did it like some others around the start of the pandemic due to all the time everyone was spending indoors and I wound up getting a few devices from Awair. After doing this for a couple of years now, at least in my home, CO2 really never rises to the level that it&#x27;s a concern. This is largely because my HVAC system is configured to circulate the air in my home every 30 minutes regardless of heating or cooling. With this feature off, yes, CO2 does eventually build up to unhealthy levels rather easily in rooms that have doors closed and related. Ultimately, this experiment gave me a greater appreciation for my HVAC system. On a side note, monitoring rising CO2 levels can, well, be used as a detection method to determine whether someone is in a room and for how long they&#x27;ve been there.

A related question: does anyone have a CO2 detector in their vehicle?<p>I keep wondering if CO2 is the reason that so many cars try to force recirculation off. I am super sensitive to exhaust fumes so I am constantly turning it back on.

Aranet 4.<p>Determined my kids rooms are big culprit with doors closed. (Up to 1400 at night) now keeping door open.<p>I doubt this will fly when they are older so looking into installing an ERV&#x2F;HRV system if anyone has any recommendations.

<a href="https:&#x2F;&#x2F;seetheair.org&#x2F;2022&#x2F;04&#x2F;04&#x2F;air-quality-monitors-comparison-list-2022-q2&#x2F;" rel="nofollow">https:&#x2F;&#x2F;seetheair.org&#x2F;2022&#x2F;04&#x2F;04&#x2F;air-quality-monitors-compar...</a> is the best comparison list i&#x27;ve seen yet<p>it&#x27;s just missing the airgradient <a href="https:&#x2F;&#x2F;www.airgradient.com&#x2F;open-airgradient&#x2F;kits&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.airgradient.com&#x2F;open-airgradient&#x2F;kits&#x2F;</a>

Yes, I got a meter that shows the number and beeps when it hits 1000 ppm, which it does sometimes in my office after a few hours with the windows closed. A good investment in productivity.

I have a ZyAura sensor connected to Home Assistant with ESPHome [1]<p>I&#x27;ve found that I need to keep my bedroom door open at night, to keep Co2 levels below 1000 PPM. Also, I need to increase my apartment&#x27;s ventilation by one or two levels for board game nights (or whenever there are 4+ people present).<p>[1] <a href="https:&#x2F;&#x2F;esphome.io&#x2F;components&#x2F;sensor&#x2F;zyaura.html" rel="nofollow">https:&#x2F;&#x2F;esphome.io&#x2F;components&#x2F;sensor&#x2F;zyaura.html</a>

I only have a TFA Dostmann CO2 monitor. It doesn&#x27;t have any data connection capabilities, you just read numbers from the display. And it needs usb power, doesn&#x27;t have batteries. Maybe I should buy an Aranet4.<p><a href="https:&#x2F;&#x2F;www.amazon.de&#x2F;-&#x2F;en&#x2F;Dostmann-31-5009-AIRCO2NTROL-Monitor-Detector&#x2F;dp&#x2F;B07R4XM9Z6" rel="nofollow">https:&#x2F;&#x2F;www.amazon.de&#x2F;-&#x2F;en&#x2F;Dostmann-31-5009-AIRCO2NTROL-Moni...</a>

I used to do it by using an Awair device, I could feed it into HomeKit which is why I choose it in the first place. Then some weird crypto thing (planetwatch.io) happend which made them really expensive and I sold it for a lot more than I bought it.<p>Since then, I don&#x27;t monitor any more and I don&#x27;t miss it as I&#x27;m always airing the room multiple times per day anyway and I didn&#x27;t really get something out of it except some pretty graphs.

Open windows.<p>There&#x27;s not much else you can do. Even in the winter, I open it long enough to change the air and hopefully without letting the heat escape too much.<p>I used the old generation Awair, they are no longer supported. Now it reads false readings about air quality, so I&#x27;ll be switching to one of the competitors. Good things is that Awair seem to have opened the door, there was not a lot of devices a few years ago and now there are a more options.

I use a kaiterra sensor, and like others have said controlling ventilation is really the only way to mitigate it. We&#x27;re looking at HRV systems now.

I don&#x27;t measure but I mitigate. I sleep with the bedroom door open and try to have a window at least cracked as often as possible.

I have a lot of houseplants, does that count?

I use an Airthings device to measure the air quality in my bedroom. I&#x27;m noticeably more groggy in the morning if there is more than recommended CO2 in the room. I don&#x27;t care that much about the other things it measures. Another nice feature is having all of the history on my phone.

CO2 doesn&#x27;t matter because it is unlikely to exceed 1000-1400 ppm. Feel free to measure it but it will be insignificant. As soon as a door is opened, levels return to atmospheric range.<p>It&#x27;s CO that&#x27;s an issue, and related to incomplete combustion.<p>I use an BlueAir 680i, so indoor air is cleaner than outdoor.

Yes. From the monitor I discovered that co2 in my home office rises from around 700ppm to 1200ppm in just a few hours unless I open a window or the door. Now I generally leave the window a little open or if the neighbours have their fire down I just open the door to the hall.

I&#x27;ve found that just having a tilted window is enough to make a difference. Then it&#x27;s always &lt;800ppm. I do monitor C02 levels in the office, and noticed that I never check the value if it&#x27;s &lt;600ppm, and that anything &gt;800ppm makes me unproductive.

I too bought Aranet 4 a few months ago.<p>During winter nights we routinely hit 3k-4k in the bedroom by the morning. During summer it never went over 900 due to open window.<p>Solution, get up in the middle of night to open balcony for a few minutes, drops to under 1k very quickly.

Not scientifically. We try to leave the windows open as much as we can, weather permitting. For even more outside air flow, we installed a screen door on our front door. Total cost was about $150 USD.<p>When we run the gas stove, I try to run the exhaust fan.

Anyone has a recommendation for a portable heat exchanger&#x2F;heat pump for locations where no permanent modifications can take place and no window units are allowed? Preferably with a working range of -30c and +50c.

How many people do you need in an apartment for CO2 to become a problem? AFAIK some carbon dioxide is even necessary for oxygen to be utilized in your body and for parasympathetic nervous system to work.

I’m surprised how many people aren’t sensitive to lack of fresh air. I yawn, get dehydrated, and generally just feel off. I’ve stayed in hotel rooms with no opening windows and barely got an hour’s sleep.

I&#x27;ve got a DIY IOT sensor feeding into home assistant.<p>Mitigation - one of my bedroom windows is rather leaky &amp; I&#x27;ve decided to leave it as is due to co2 concerns.

If you have a properly sized range hood, won’t that pull out the CO2? Maybe you just need to leave it running longer? I could see a CO2 meter helping with this.

I got a cheap CO2 sensor from Amazon, and put a fan in my window blowing outward.<p>That was enough to lower CO2 levels to the bottom of the sensor&#x27;s sensing range.

No.<p>And from studies I read the issue with gas stoves are pretty much exclusive to developing countries with bad stove standards and poorly ventilated kitchens.

Yes - Aranet CO2 detector; we also carry it into a cars and open our windows when the CO2 in the car gets too high.<p>We use electric stoves, but would prefer gas.

I have had a &quot;Netatmo&quot; device for some years and it seems to work well. Whenever I use my gas stove the CO2 reading increases.

For better or worse we live in a leaky old house. If I lived in a modern, tight house I absolutely would install a HRV&#x2F;ERV.

Not CO2 specifically, but I bought a fancy detector and air purifier that removes particulate pollution from my living space.

No. Never even considered it. I also plan to replace an electric stove with a gas stove in the near future.

Not only have I never done this, I was not previously aware that anyone else did, either.

there is a ton of devices that do that on amazon. here ( Brazil&#x2F;beach ) i get only 300-400 ppm, ps: i dont use gas to Cook&#x2F;shower. everything is elétric

yes, and also yes — I replaced my gas range with an electric induction range, considering installing heat recovery ventilation

When the air starts feeling thin I simply open the window.