AirGradient Forum

Summer, windows, VOC, stack effect?

#1

Using AirGradient ONE (Model I-9PSL). Measuring 880 cubic foot room. Specifically TVOC levels. Have noticed that during day or night when windows and doors of house are open and lot’s of air movement, that TVOC level tends to around 65. On evenings when closing doors windows, shortly thereafter, TVOC levels go up. Usually around 450. If I open room window and door, and run basic window fan full blast to pressurize room with fresh air, quickly goes back down to 65ish. If I keep room window and door closed, and run my EVR, WhisperComfort® 60, Energy Recovery Ventilator | Panasonic North America - United States all night, the level goes down a bit, to 350 or so. That seems so weird, being that the EVR is meant for whole house spaces and is also set to pressurize room a bit. EVR pulls in fresh air and vents out stale air. If you want similar examples, you can look on net using same title for this post.

House built in late 60’s. Climate, late spring, 49th parallel. No activities noted that would cause the rise. One occupant in room and one pet. So sure, that causes some TVOC. However, as noted, window fan clears it out and EVC does not, with occupants.

Apparently I am not alone in this. Anyone else here having this or has figured out any good answers? thanks.

#2

In the evening do you use an ultrasonic humidifier, CPAP, acetone, cologne, alcohol, etc that could cause a spike? 500 is the max reading, so I wouldn’t expect general life to cause that big of a jump without good cause.

Recently paint the room?

#3

All good questions. None of the above. No cooking either at times. Neighbors sometimes have their bounce sheets or whatever that is and it’s so strong in the neighborhood outside I can barely breathe, but that’s not it either as happens on nights when that’s not there. Also checked out for plumbing issues.

Nearest reasonable guess I have is Stack Effect. The house has been closed in a lot for like 35 years due to agoraphobic previous owners. So everything is saturated with odors. I mean everything. And all kinds of different odors. And in strange places, like walls around base of floor stairs. For no reason I can think of. Plus there’s a tremendous amount of clutter. Not dirty or garbage, just clutter. Walls and ceilings have textured plaster on them, not just paint on drywall. I think the plaster is saturated as well. So net total of TVOC of all that is transferred around via Stack Effect. I also think the walls and ceiling in the room were saturated and are gassing off. (Been thinking about trying a Bake Out of that room as a test) (House odors have improves tremendously in the last few months since I moved in due to opening as many doors and windows I can as often as I can. But still, once air outside and inside stops moving in evenings, odors come back inside. Fresh air from outside is definitely key)

I found this description on net. " During winter months, warmer air will enter the basement, crawl space, or lower level and exit through the attic or upper levels.

In the summer, the stack effect is reversed. Warmer air enters through the attic and upper levels, cools, and then travels down and out of the basement, crawl space, or lower level. "

The summer version puzzled me, as my room is on the top floor with no opening to attic. And attic would probably not have TVOCs as no molds or anything there. I am considering that in evenings, the summer stack effect reverses again for the night as things cool down, but have yet to research my theory on that.