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High VOCs when Steam system heats up

djd Member Posts: 18
edited October 2020 in Strictly Steam
Hi folks - bit of a mystery on my hands that may be nothing at all, but wonder if anyone has seen this before.

I recently bought an Awair Element IAQ monitor which I’ve found pretty informative in different settings in our home. It measures Temp, Humidity, CO2, VOC, and PM2.5 and seems to correlate well to various changed of conditions (e.g., cooking, stirring up dust in the basement, spray painting in the vicinity, etc).

That said, I’ve noticed that a lot of the time (but not all), when my boiler fires, the VOC’s shoot through the roof for a few minutes (5-15 minutes). This doesn’t happen immediately when it fires, rather it’s after the header and pipes are mostly heated up. It typically dissipates just as fast as it arose, and much faster than CO2 or Humidity changes in my closed basement.

I recently had the system serviced ahead of the heating season and I’m pretty sure they added some corrosion inhibitors and what not (I probably should know what), but I doubt this would be volatile otherwise would be gone pretty quickly.

Anyone seen anything like this? Perhaps something obvious I am missing.



  • Jamie Hall
    Jamie Hall Member Posts: 23,322
    Paint on the pipes. Paint on the radiators. Something put in the water (I'd bet on that one first -- and, incidentally, unless the boiler water pH is bad, there's no reason to put anything in it at all).

    Does the machine tell you what VOCs are present? That's a pretty broad category of compounds -- I seem to recall several hundred, depending on exactly which list you consult -- 8260D has about 80, for instance. Some of them are not so good for you. Some of them you have in pretty decent quantities around the house quite normally.

    So -- without knowing what it's picking up, the measurement is worse than meaningless.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England