I have a recent model indoor sensor, that measures “experimental VOC data.” It has always felt pretty accurate as far as we can tell - rising and falling with often explainable patterns. It never reads below 50, not even once - even when we have windows thrown open on a breezy day. I’m not sure what to make of that. But now suddenly it is ALWAYS high - it varies on how high, but it hasn’t dipped below 150 for several days, and has gone as high as 350. There is nothing that we can figure out that could be causing this (though we are concerned that there is, in fact, some reason that makes this accurate). However, we experimented with holding the sensor directly in an open window and it still only went as low as 125 for VOC’s. Could the sensor be malfunctioning? I know it’s experimental and that it’s never clear what kind of VOC’s the sensor is reading, but this is disconcerting. I’ve tried many times to reach purpleair, to no avail. We live very close to the ocean, and while it’s no more or less humid recently than it ever is, we have wondered if the ocean air has, over time, damaged the sensors. Has anyone else experienced this? I know only the newer models measure VOC’s.
Hi @OceanAir
As you have noted, the VOC readings are experimental, meaning we’re unsure of what they indicate. Right now, any number of factors, VOC-related or not, could be affecting those values.
It’s important to note that the VOC numbers reported are not based on any public health standard. Rather, they correspond to a scale developed by Bosch, the manufacturer of the VOC board.
There is no current health standard for VOCs, more information is available here: Volatile Organic Compounds' Impact on Indoor Air Quality | US EPA
Thanks! And yet - I am more talking about the fluctuations over time. You say they could be responding to any number of factors - VOC or not. What kind of non-VOC factors would affect the VOC readings? We are not using or doing anything differently, but suddenly for weeks on end it will read 200-390 ppm for VOC’s, and then drop down to maybe 100-150 for a while. It used to read much lower (though never once below 50, even in clean outdoor seaside air). I am suspecting that our unit is malfunctioning, and/or that ocean air damages the sensors? I realize that there is not a public health standard and that many pollutants can raise the reading, but I am trying to compare it to other times within the exact same environment. And there are loose standards for what constitutes low/moderate/high VOC pollution, as I was given the BOSCH info sheet from PurpleAir which delineates this (under 50 is good, 50-100 is lightly polluted, etc.). Apparently we have never even for a moment had good clean air in our apartment, which seems - odd.
Will there be any updates to this, to make the info more useful?