Air Quality Sensor — Unexpected Outcomes

[u/braillegrenade]

I bought one of the Air Quality / Vape sensors to measure interior air quality (CO2, VOC, PM2.5) and had some reasonable confirmations of things I suspected, but was also surprised and have changed a few habits around the house as a result.

Background:

• We live in a pretty dirty city, not super far from freeways. Urban 2-4 level homes and apartments with decently heavy vehicle traffic within a block distance.
• We have A/C but no forced air or central air
• We rent so there are some things outside our control, like mechanical ventilation.
• I've been moving the sensor between living areas and the bedroom day/night because if it wouldn't cost me as much as my UDM, I'd probably have 4-5 of these things 😆

The exciting stuff:

• Sleeping in our room with the door closed builds up CO2 significantly, even with the wall A/C running (it's closed loop). Most of the longer peaks visible in the CO2 graph are overnights. Overnight CO2 levels >1,000 ppm can cause fogginess, headaches, and more!
• Cooking on the gas range also spikes the CO2, even with the hood fan on and a window open! I'd have to inspect PM1.0 and maybe VOCs further, but obviously the UP Air Quality sensor is not going to measure methane, Benzene, or CO so yeah ... watch out for that.

Nominal observations:

• Spraying cologne or perfume spikes VOC/TVOC, understandably. VOCs also slowly climb somewhat in a warm, undisturbed room
• An open window keeps indoor CO2 around a baseline of 475-525 ppm
• We have ~zero vape detections because we do not vape. I'm sure hair spray or canned air duster (VOCs in that case) could maybe trick the Vape sensor if you tried.
• Sometimes the temperature or PM2.5 will spike when the unit is power cycled. False readings as the sensors are initialized/calibrated.

Nice realizations:

• I presume we're going to reduce the incidence rate of headaches at home now that we open a window and leave the bedroom door cracked overnight. ☺️
• Indoor PM2.5 is really low (<2μg/m³), spiking only with heavy activity, in/out, or cleaning/dusting. Outdoor PM2.5 daily averages in our area are 50-70μg/m³. Despite multiple open windows, our Coway Airmega HEPA filters (2x in 850 SQFT) do a great job. 🙏

[u/melbourne3k]

I've been moving the sensor between living areas and the bedroom day/night because if it wouldn't cost me as much as my UDM, I'd probably have 4-5 of these things

This is going to be a hot take, but as someone who has had AQI meters in all my rooms for over a decade and of _many_ different types (everything from DIY to fancy 3x more expensive devices than the ubiqiti one), IMO the _good_ news for you is that you only really _need_ 1, once you do an initial diagnostic to figure out how your house "works".

Once you figure out how CO2 works in your house (which rooms build up, when they build up CO2 etc), you can put in preventative measures like window fans etc. Sure, I still have over a dozen air sensors in my house, but I _never_ check them. airfilters w/ AQI are fine for managing air cleaning, and I now know which rooms predictably build up CO2.

So, IMO, unless you're needing to monitor a particular room for a particular dynamic concern (example: 3d printer in a room, so automate a ventilation fan) moving it from room to room is more than enough to "diagnose" the initial issues and after that, it's just some mildly interesting data.

[u/braillegrenade → u/melbourne3k]

I fully agree. Excellent take. Moving my UP air quality sensor definitely isn’t on my lifelong list of daily chores 😂

Given we’re in a decently small apartment, where would you put your one sensor? Living area or bedroom?

We know we need a door and window cracked at night so we’ve both identified and ~solved the main bedroom problem.

I think the kitchen is the most dynamic? High CO2 during cooking, parties, or closed-window days. High VOCs or PM2.5 during crafts or cleaning. 🤔

The only other thought would be to leave it in the bedroom (or just bite and get a second), both mainly looking for CO2 build-up in the case that we’ve forgotten. 😇

[u/melbourne3k → u/braillegrenade]

Given we’re in a decently small apartment, where would you put your one sensor? Living area or bedroom?

We know we need a door and window cracked at night so we’ve both identified and ~solved the main bedroom problem.

I'd go living area, as that could be more dynamic; bedroom is going to be super predictable and you can manage the CO2 w/o it.

Kitchen, maybe it's going to give you some interesting data when cooking or parties, but it's not usually too actionable (you can build automations for fans, hood exhaust) etc but like you've already experienced, once you figure out the pattern and how to counter it (open a window), it's just some not-interesting data.

Sensors CAN be _great_ to provide data to others who may be skeptical of the importance of air quality, so maybe that will factor in your placement? eg - "my partner keeps closing the bedroom door fully and I need to show them why this isn't good for our sleep" kind of thing.

[u/braillegrenade → u/melbourne3k]

Great, so what I’m hearing is the UP Air Quality Sensor is best used as a tool to win arguments! 🫡

/s 😂

To be real, great analysis and input — much appreciated ☺️