1

I have been racking my brain and searching google to try and figure out the source of the VOCs in my house. I've discovered a few, but they don't quite make sense to me and I'm still confused as to what may be causing the current spikes.

voc data with particular tests labeled

The Furnace

The furnace and blower have one majorly obvious problem to fix. The air intake does not pull air from outside the house and instead pulls air directly from the basement. (furnace and fan only)

I'm planning to have this fixed. However, I ran a test where I opened every single door and window in my house (even in the basement) and ran the blower motor (fan w/ all windows). I would have expected all the inside air to be exchange with outside air and have super low VOCs. Most windows in my home have been open for the past 4 days at this point.

I'm hoping to have an HVAC tech come by this week and fix the air intake so it pulls from outside the house, but at this point I'm not really confident that will help. Something seems inherent to the ductwork/blower that is causing the VOCs.

Night

This is what I can't understand, and I've tried reading many, many sites on Google, but they are all very vague. Why do the VOCs in my house spike at night? I live in a small town and it has been getting to around 40F at night; I can't really figure out where these VOCs come from. Almost all of my windows are open now and if these VOCs are coming from outside my house it won't matter if the HVAC tech fixes the air intake or not.

The sensor is in my bedroom, but I have all bedroom windows open all night.

Help?

I need some idea on how to specifically identify the source of these VOCs. Which chemical is it and from what are they coming from? Is there something non-intuitive where by ventilating the house I'm inviting VOCs in? I don't know.

Addendum

Does mold actually create detectable VOCs? https://www.americanairandwater.com/mold/

Breedly
  • 195
  • 7
  • 4
    At this point it would probably be useful to take 'control' samples of the air *outside* your house at various locations. It's entirely possible that there's an external source which you haven't accounted for... – brhans Mar 02 '22 at 13:08
  • 2
    Generally, only combustion air for a gas-fired furnace is drawn in from outside. You don't want cold outside air being brought in to the furnace's return ducting because then you have to warm 40°F air to ~70°F instead of warming ~65°F air up to 70. If you want to bring in fresh, outside air (with a well sealed house, that's _very_ advisable) you would want a heat recovery vent which will be more expense than just a simple air intake. – FreeMan Mar 02 '22 at 13:21
  • As @brhans suggests, start with figuring out exactly what your sensor is measuring, its accuracy, and what baseline outdoor values are. Is the sensor calibrated in any way from the vendor? – Armand Mar 02 '22 at 15:40
  • your average is well below HUD acceptable limits, about half. do you live near railroad tracks? – dandavis Mar 02 '22 at 17:40
  • I think I likely have a mold issue. The duct work is very dirty and there was definitely mold in the bathroom which I have had removed. I generally notice I start feeling not great when these lines turn yellow. – Breedly Mar 02 '22 at 20:14
  • When did the VOCs start? How long have you lived there? Do your neighbors have similar issues? – MonkeyZeus Mar 03 '22 at 20:44

0 Answers0