We’ve been going through some tough times and a lot of bad contractor advice so please have some grace with my lack of knowledge. 

We were getting really bad air quality (measured via uHoo, Amazon, and later Broan Overture devices which all correlate with each other). One of our hvac contractors thought this was coming from our makeup air system. So he chopped that system, sealed some attic air infiltrations, and suggested we spray foam the attic because of all the dust we were getting. Then someone else came in and decided we needed an ERV. Something special to note is that the ERV has dedicated ducting to top floor only due to the air handler being on the first floor and not being able to access the sub flooring ducts. Turns out the issue all along was our gas water heater (inside the envelope) was improperly vented. No amount of positive pressure could overcome natural gas exhaust being expelled into our attic (sarcastic sigh).

I am still noticing spikes of bad air quality that typically correlate with spikes in humidity. I’m having chest tightness and brain fog. It makes me think the bottom floor isn’t getting enough fresh air as that’s where most of the air pollution tends to start, then circulates to the upstairs. I think the air pollution works its way into the now conditioned attic and then falls back down when the humidity increases at night and in the morning. We live in Florida so pretty much year round high humidity. 

I am happy to go back to the basics, get a blower door test, pay for ventilating dehumidifier, hook make up air back up, or hire someone knowledgeable but I just want this fixed before our baby is born. I will pay someone consultant fees or whatever we need to do to fix this. If you’re still reading this, thank you so much.