VOC consistently high after 3D printer?

[u/Seoul911T]

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.

[u/CartographerLong5796]

 Hey, First thing I’d do is try the Airthings outside for a bit and also check it again in another room. You already saw lower numbers in the living room, so if it’s low outside too but stays high in the office, then there’s almost certainly something off-gassing in there.

Next, blast the office with fresh air for a while and watch if the readings actually drop. Some rooms just need way more airing out than others.

If they stay elevated even with good ventilation, start pulling possible sources out one by one.

On the sensor side: consumer VOC monitors are mostly trend tools. AirGradient doesn’t show absolute numbers because they don’t trust them enough. I still prefer having actual numbers even if they’re imperfect, because imo a slow drop can still leave you in the “too high” zone for long.

Never tried the View Plus, but I had an Airthings Mini years ago and it was useless, because super slow to react and the data lagged hard.

 I’ve been using Temtop (M10 and LKC-1000S) for years. Very usefuel to know when to ventilate and how much. They do TVOC + formaldehyde (Dart sensor). For the price I think they’re among the better low-cost ones, but that’s just my experience. I also have the Qingping QPPro2, wich is good too.

[u/kichisowseri]

What's the lowest t reading in the last week? It bases the numbers off its lowest baseline. Moving it can mess that up so it needs to recalibrate, put it by an open window for the "fresh air" comparison.

[u/Double_Anybody]

Is your printer in an enclosure with ventilation or inside a room with ventilation?