I did some math based upon some estimates for BTU/hr that are typical. The gas-fired water heater is about 40,000 BTU/hr, the furnace about 80,000 BTU/hr, and clothes dryer about 20,000 BTU/hr. So, combined (if all are running at the same time) that is about 140,000 BTU/hr. The confined space calculation is 140,000 x 50 cubic feet / 1,000 BTU/hr <= 7,000 cubic feet. Is your basement bigger or smaller than 20’x45’x8’ (=7,200 cubic ft)?
Does the interior door to your basement have vents (openings) in it?
What is the blower (motor) and additional sets of piping above the water heater in the picture? Is the water heater a “high-efficiency” model (looks like it)? Is the furnace also a high-efficiency model?
I only wish. There must be a reason why all carpeting, furniture, bedding, every crack and crevice is full of this sediment. Which has a glowing effect about it. See my photos I attached of carpeting. I wish I could post videos, I’m rather tired of people not believing me and chalking it up to be just some crazy female.
This is indeed a complex situation which is hard to diagnose from afar. You have pointed at a number of potential issues, some could be related to the problems you are seeing, others not. Perhaps some explanations on how some of these systems are supposed to work might help give you some clues as to what is going wrong:
Your water heater is what we call a direct vent appliance, it draws combustion air directly from the exterior of the house through one (usually PVC) pipe and vents hot exhaust through another pipe back to the exterior. It should be a closed loop and not draw any air from inside the house and, therefore, should not cause any negative pressures as long as the air intake is air tight.
Your furnace is also a high-efficiency direct vent appliance. One (typically PVC) pipe drawing external air in for combustion and another (typically PVC) exhausting warm air out. It should also not contribute to any negative air pressures inside the house as long as the air intake is air tight.
Backdrafting is when combustion exhaust air is sucked out of the exhaust vent by negative pressures back inside the house, usually caused by another appliance or combination of appliances and/or a fireplace. Not only do you get more CO2, you can also get CO (carbon monoxide) inside the house that can kill you.
Both of those combustion air flows for the hot water heater and furnace are by induction blowers (fans), so it should be near impossible to backdraft those appliances if the induction blowers are working correctly. It is also likely that the furnace or hot water would shut down if it detects that the induction blower is not working.
You indicated that all of your inlets were on one side of the house and exhausts were on the other in your pictures. That is good. However, if the furnace exhaust indicated was actually an air inlet, that could account for how CO2 would increase inside the house (drawing exhaust air from another appliance back into the house). Another is if there was a leak in the exhaust pipe (or in any of your other gas-fired appliances). Both of those situations would also be dangerous for CO poisoning.
The CO2 levels in your house were not high and I presume you have CO detector that is working.
With most of your venting and ducting in the basement, the only ducts in your attic should be for the bathroom and kitchen exhaust fans. These should extend through your attic to the roof or exterior walls. Exhaust fans do cause negative pressures inside the house, but those are relatively small motors with low pressures and air flow (e.g. 50 to 100 CFM).
The ERV draws clean air from outside your house and exhausts stale air back out. It appears to be connected to your existing furnace plenums. It typically has two small blowers inside in the range of 200 to 300 CFM, but those should roughly be in balance and not contribute significantly to higher or lower pressures.
Your clothes dryer is also gas-fired with an induction blower. However, it probably gets its combustion air from the basement where it is located. So, it will cause negative pressures inside the house as well, but in the medium range (e.g. 100 to 240 CFM).
Based upon the above, if everything is working as it should, it is hard to see how cellulose from the attic could be getting sucked into the interior of the house. Something is not as it appears or there is something that is missing from our information.
Based upon the above observation and hypotheses, me thinks you nailed it.
Might be lint not cellulose, on the carpet and bedrooms, together with moisture/vapor, from a damaged dryer vent duct. Just saying…
Your analysis is quite intriguing and I appreciate you putting that all together for me.
My clothes dryer is not a gas dryer though, just to throw that out there.
The kitchen range vent leads to the outside on the side of the house. The bathfan leads to the attic, which I believe is the only thing vented into the attic space. There is nothing else up there but lots of cellulose on top of fiberglass batts. I had presumed the glittery material in my carpeting was fiberglass, although I’m not so certain about this after more investigating.
The backdrafting of appliances is very real, I have this on video in regards to my furnace and water heater. If you’d like to see them you can email me since I’m unable to upload them on this thread. Castilemichelle@gmail.com
I certainly appreciate your thoughts on all of this as I continue to try to diagnose this problem.
That’s the thing, there is no damage on the dryer venting or duct. It’s perfectly fine. Although this dryer of mine does emit a lot of heat, making the clothes hot to the touch. I’ve also noticed whatever it is in my air, cellulose according to the health department testing completed, could very well be from my dryer just as well as the attic. But since both my furnace and water heater are backdrafting, with my clothes dryer in the same room, it only makes sense as to what is occurring could very well be coming from that dryer due to backdrafting just as well as the others.
If you have not seen the photo I had posted of my return vents I will post them here. As well as a very close up photo of the dryer lint screen with strange material on it. I presume this to be cotton perhaps as it’s heated up from the dryer. I’m needing both a building scientist as well as an actual scientist to figure out what exactly these particulates are that are located all throughout my home and in everything and every crack and crevice.
FYI: we had placed screens over our returns as previously advised to do. We have since removed them.
Thank you,
Yea, I think I did.
