I got AirQ Multigas but according to my Airthings device it’s doing absolutely nothing for VOCs level in my house. I even tried putting it in a room with closed windows and door but still, made zero difference..
I have no clue what conditions AirQ tested these devices in to conclude they work, but clearly they had nothing to do with real life
Desperate for a solution because I have MCAS so this is seriously affecting my health.
Max level VOCs reach with closed windows / doors - 1,100 ppb.
Down to 40-50 with all windows opened but thats becoming impossible because of colder nights (they have to be wide open).
Airthings works: when I put it outside within 30mins levels go down to 30 or so (i.e. normal for the outside).
Any idea why Multigas doesnt work at all? Ive been running it continuously on med-high for 10 days now.
Any other whole house system I could try?
Do you mean the IQAir MultiGas purifier? If you could send a link, that would make it much easier for me to try and provide some insights. I’m happy to help if I can!
I ran an IQAir MultiGas for MCAS for many years, replacing all the cartridges at least once.
The term VOC is pretty useless here - covering too much ground and trying to reduce a complex topic to a single number.
Plants, animals, cooking, and even you emit VOCs of many flavors. I liked to believe that the MultiGas was significantly reducing formaldehyde emitted into our apartment from the cabinets and flat pack furniture (I got enough relief after painting a special sealant on the cabinets, disposing of all the furniture and replacing with hardwoods, and getting the huge laser printer off my desk, that I never rented the formaldehyde meter again).
That said, knowing what I now understand, I would not expect to see the VOCs reported by a cheap meter to drop at all when running the MultiGas. It is probably hung up on and reporting something like mild alcohol fumes that the sensors are overly sensitive to.
Thanks for sharing your experience I appreciate it! I don’t think it’s the case for me though because I only moved houses three weeks and was using the same Airthings device for months prior to moving - VOCs were never higher than 250 there safe for random very brief spikes due to frying something or hair dryer.
Currently in the new place the VOCs are 1000 or slightly higher with windows closed even when I’m not home. Only drop when I open ALL windows WIDE - then VOCs drop to very low levels.
I just wish Multigas allowed me to leave the windows just slightly open and - if working right next to my bed - creates a safe space for sleep.
But it doesn’t do that .. I put Airthings literally right next to the outflow air (actually touching multigas) and yes then Airthings showed vocs dropping slowly .. but if the only scenario multigas works in is when you stick your nose to multigas then for me it is not helpful at all
It’s also the reason I don’t think Multigas removes anything in a room and why I think Airthings works.
@DavidWilson has some very good points here and it’s what led to this massive thread:
Long story short, VOC readings from ‘low cost’ sensors are very difficult to interpret and shouldn’t really be relied on much other than looking for general trends. This, unfortunately, is common across all air quality monitors brands in this price range, whether Airthings, PurpleAir, AirGradient, or otherwise.
I can’t remember exactly what scale/index Airthings uses (I will need to double-check this), but most monitors use a 1-500 index, where anything below 100 indicates a decrease in VOCs and anything above indicates an increase. 100 itself is the baseline (a rolling average based on exposure over the past 12 or 24 hours).
Based on this, I believe Airthings may be showing an ‘absolute’ number in parts per billion, but this is just derived from the relative index I just mentioned so it’s not particularly useful. Of course, that’s before we get to VOCs themselves, some of which are very harmful but some of which are also harmless.
I don’t say this to add more confusion (I hope that’s not the case!), just to say that a VOC sensors are, unfortunately, quite limited in usefulness and I wouldn’t conclude that the purifier doesn’t work based purely on this. If this is a big concern for you, I would definitely recommend a VOC patch test where you basically place a collector in a room for a few days and then send it off to a lab for analysis. I’m not sure where you’re based, but if you’re in the U.S. I believe these are generally not too expensive and they’re definitely the best way to get conclusive answers.
