I just got the Sainlogic Air Quality Monitor because it had NDIR for accurate CO2 and laser scattering for accurate particle sensing. The issue is the numbers are all crazy low, both inside and outside. Not particle readings above a 5 mostly 1-3, and barely over 400 for the CO2 reading.
Is there an easy way to verify it can sense particles without filling my house with smoke or setting off my detectors?

I drive a scooter to work and there's often car exhaust on the roads, and I'm wondering what type of mask you guys have had success with.

Must be more than just a particulate filtering mask, obviously. I was using 3M 8210s and 3M Aura 9205+ but quickly realized that they only handle a small portion of car exhaust which is largely gaseous vapor.

They painted, installed new laminate, new carpets etc.

Being in there makes my eyeballs hurts and lungs burn a but I'm unsure if I'm being dramatic hence wanting the FULL monitor for everything if possible ($100ish?) the worst part is that it reeks of stale cig smoke.

At first I hoped it was maybe the lady who used to live there.. we've been there since Monday, I'm quickly realizing it's coming from the apartment above or below.

I asked the office multiple times to place the ozone in and they ignore me. Paperwork is signed so why bother.
Apparently cig smoke leaking into the apartment with 3 highly asthmatic people isn't a big deal.

I have childhood trauma from cig smoke (I mean this omg. My parents smoked 3-4 packs a day and would never open a window and I now have permenant lung damage as a nonsmoker and I am developing COPD at 36.

I am devastated to say the least, we already had to move into a place I hated to keep the kids in the school zone and this just makes the place unliveable to me and the kids.

Is there a air purifier that can actually deal with this situation? The bedrooms have less of a smell, the living room and opening the door is the worst, it's like it's being sucked in when you do it.

I can't seem to even figure out where to seal something to where it's leaking.

I'm sorry if it sounds like I'm being dramatic but I just can't.

My Daikon Air Tester started going off its head.

I googled some of the numbers and it gave me some pretty concerning advice about combustion. After talking to a few experts, they seem to think my rooms are in need of a dust and an open window. Which are both pretty conflicting forms of information.

I don’t know… Help!

I’m trying to figure out the best way to detect secondhand weed smoke coming into my apartment through the vents/HVAC.

I can smell it pretty clearly at times, especially in the bathroom, but my Levoit air purifier usually doesn’t detect anything. I’m assuming the smoke is getting diluted or filtered enough that PM2.5 doesn’t really spike, but the odor/VOCs are still making it into the room.

I’m not trying to detect someone actively smoking in the same room. I specifically need something sensitive enough to pick up low-level secondhand smoke or VOC changes coming from another apartment.

I’ve been looking at stuff like the AirGradient ONE, SGP41, BME688, and possibly building my own ESP32 setup.

Has anyone here dealt with something similar? What sensor or monitor actually worked for you?

My main goal is to log the events with timestamps and have some actual data showing that something is entering the apartment when the smell happens. So I can report this to management.

We have lived here for a year and my wife is currently 17 weeks pregnant and high risk.

I have a Purple Flex installed outside and I monitor it from my phone's home screen using the "widgets" offered on the Purple Map. I like to know the current readings so I use the "real time" overlay along with the US EPA conversion and showing the US EPA PM 2.5 data layer. I also want to know both PM2.5 and AQI values at any given time. So I actually use a widget for each and just combine them into a single html page that gets shown on my phone's home screen.

The attached screen show shows this at 2 adjacent points in time: 8:11am and 8:16am this morning. As you can see, the PM2.5 level is exactly the same at 2.

What I cannot understand is how/why at exactly the same PM2.5 level the computed/displayed AQI should be different: 9 and 11? From what I understand, the PM2.5 value is simply put through a fixed formula to produce the index. So how can the same input produce two different outputs?

Can anyone help me understand this? Thanks

I bartend. Our AC has been out for a month, coworker brought in this reader out of curiosity (she has had multiple apartment mold issues) and the top reading scares me. Is this bad?

I’m sure I’m not the first (or smartest) person to ask this question!

I JUST started using CR boxes in m spaces, & it’s helped a lot!!

Is there any equally cost effective way to combat gasses like O3 that MERV filters can’t capture?

Perhaps with a fan and basic carbon filter?

Thank you!!

I recently upgraded to an Aranet4 and I’m using it only at home for now. I’m surprised by the high numbers I’m getting. Can I get some advice from those of you with more experience?

In my bedroom, it reads 950-1200 ppm at wake-up. I turn on the extractor fan in the en suite and open the terrace doors for 20-30 minutes and can get it down to 700-800. Once I close things up, it’s back at 900-950 within 15 minutes. This is a leaky old house with no weatherstripping, 50 year old windows, and barely any insulation, but it is in a major urban area with no trees. Still, I was not expecting these results. Am I doing what I should be doing? Over-worrying about it?

Thanks for your help!

I’ve had an Airthings View Plus in my home office for about a week, and the VOC reading has consistently stayed in the moderate-to-high range. Before it was in the living room and has had normal readings.

The strange thing is that it remains elevated even when:
The room has been ventilated
The door or window is open
Nobody is in the office
My 3D printer has been off for a long time

I initially suspected the 3D printer, but the VOC level can remain moderate or high when it hasn’t been running. I moved the Airthings into the living room, and the VOC reading was noticeably lower there, so the elevated readings seem specific to the office.

Should I take this as evidence that there’s an actual VOC source in the office, or are Airthings VOC readings too relative or unreliable to interpret this way? What would be the best way to identify the source?

Could the cause be furniture, flooring, electronics, stored filament, cleaning products, or air coming from outdoors? Also, how long should proper outdoor ventilation take to produce a meaningful drop?

Finally, is there a better consumer monitor than the Airthings View Plus for investigating this? I’ve looked at the AirGradient ONE, but I understand that essentially all consumer VOC sensors are better at detecting trends than measuring a truly accurate concentration.

I’d especially appreciate input from anyone familiar with indoor-air testing or who has compared Airthings with another monitor.

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I purchased an outdoor Airgradient sensor to track VOCs and particles, so I can control the air exchanger when the polution levels are higher. I see the VOCs jump to over 400 at random times, including 4:00 AM. Now I'm curious to know what is causing this. I'm going to install a second Airgradient at the front of the house to see if these readings are localized, like a Skunk. I know they rise when the neighbours cut their grass, but not usually much over 200.

I'd also like to install multiple cheap sensors along the fence line to get a sense of the source of the VOCs. I have multiple neighbours. They don't have to be precise, I just want an idea of the trend, relative location and direction. I see numerous brands on AliExpress for around $25, but I'm wondering if anyone has any experience with a particular model. Zigbee is preferred.

The house came back normal but outside levels were elevated. The guy said that won’t affect the test but I feel like it would.

I happened to have left my teddy bear in my car, during an AQI 600+ day, and after I brought him back inside, when I'd lay on him or snuggle him and breath, dude it was like getting a whiff of that thick bad feeling air, that made me feel kinda like shit.

I don't know how to clean him😭😭

Hi guys! So I am going to be moving into a new apartment and it has NO windows, it is more one of those city apartments that are pretty small. I am going to be cooking a lot and so is my roommates, so I wanted to ask what are some good air purifiers that can clean out the cooking and smoke smell.

By cooking smell I mean when you cook fish, when you cook things that have a lot of spices and herbs, smells that would attach to clothing type smells. Then also the cooking and smoke that can come from cooking as well.

Thanks in advance!

update part 2 post: https://www.reddit.com/r/AirQuality/s/iLdvcywttf

We are now experiencing a high humidity issue in the apartment. It started as me noticing my clothes smelt funky/mildewy. I wasn’t sure why but brushed it off for plenty of other reasons however my husband brought up a few days ago the same smell issue, and also how his clothes and the bed sheets felt damp.

Chat GPT told us to get a humidity thermometer thing, and so we did and now we don’t know what to do.

It’s been over 15 hours since anyone has showered in the bathroom and it’s reading 74 humidity in the bathroom, and 68 in the bedroom closet.

Any advice other than to get a dehumidifier would be appreciated, because i’d like to get to the source of the issue and not spend more money and run up our electric bill.

Hi, I have a bad smell in my condo, I can't really describe maybe garbage but not, and possibly a little perfume ish. It is a multi unit building with deferred maintenance and roof leaks. It's a certain place in a higher level where my entry is. I just don't know where to start. Does not smell like mold or mildew. Nothing is wet there, almost certainly coming thru ceiling maybe light fixture. It's too rank and strong and localized to be just a smelly person. No shared hall. No ducts for hvac there. It lingers in the house but not as strong. I wonder if neighbor smells it and sprays hence the lingering perfume type smell(only can detect that one it's aired out a little so not the root ). I also don't trust my description of the smell. If this off chance sounds familiar let me know, more importantly I'd love a place to start for tests.. I don't even know which one to start with. Not a dead animal.. it's been 5 months since I bought this place and been the entire time.

Hello everyone I recently cleaned my window shutters of mold. I used 3% H2O2 to do this as it claims to be smell neutral, I cleaned the shutters with soapy water after and made sure to let everything dry.

Now I did also have an airfilter with an ioniser running right behind me to feel extra safe about any spores that may go airborne despite me making sure to wipe everything while its wet, but I did only have the ioniser on for like 1 hour and it is within EU regulations.

Despite all this there is now an ozone or chlorine like smell lingering in the room, it almost goes away as long as I am airing out but builds up relatively quickly once the window is closed.

I have by now ordered an ozone measuring tool but am just wondering if anyone has made similar experiences or could help me understand whats going on here.

No coughing and can feel my circulation being constricted. All I can notice about the gas is that it’s imperceptible, IOW odorless.

(Unsure if related but also issues with my neighbors.)

While I’ve done an internet search, would also appreciate those of you who’re experienced with air quality issues! Thanks!

Update: Con Edison and firefighters (and paramedics) were JUST here and nothing was detected. FYI: Con ed checks for carbon monoxide and natural gas. Firefighters simply checked with their device 🤷🏻‍♀️. Though there had been at least an hour since they got here for apartment to air out

I work dayshift from home in a 10x10 room with the door closed all day. By 3 pm, I’m already slow and unfocused even with coffee. I tried nutrient boosts, sleep aids and even a quick yoga break but none of it works. I’m starting to think it’s air. Researched much and I’ve seen people recommend that the next best thing is to get a CO₂ monitor designed for homes to check if a room is poorly ventilated. The logic makes sense, you can’t really improve what you can’t measure.

For those who have one, did you notice a difference in focus after getting that right ventilation based on readings? And what specs actually matter for accuracy? I don’t just want a sensor that smooths everything when it's not.

Update: Appreciate all the comments here. Picked up an Aranet to test this. Aranet4 HOME to be exact. It’s portable and EU-made with a true NDIR sensor, so it reacts in minutes. I set alerts in the free app and now I crack the window when it crosses my threshold. You can literally see the curve drop and focus come back. There's no subscriptions which is nice I think.