I'm having minor breathing issues and suspect the home air quality, which seems to be excessively full of particles/dust. The air quality is visually noticeable daily, regardless of basic cleaning/outside air steps take the day before.
Background: I bought the home last fall, it was a DIY 1700sq ft remodel built in CO in 1980 and the home inspection found nothing substantively wrong. It has central air - electric single unit AC/Heat Pump.
Just before the winter I had the attic insulated and sealed with cellulose. A short while later I started noticing the breathing issues and dust in the air. There is no HVAC in the attic, and it started getting cold around the installation time, so perhaps it's just a misleading coincidence.
I have replaced the HVAC filter several times and use one of the higher quality HEPA filters (rated for smoke particles). I had a company come in and clean the ducts. I have vacuumed, dusted, and had all the windows open on days 65F+ to circulate new air in, without engaging the HVAC system more than a couple of times. The picture is less than 24 hours after such a complete clean and open window day and shows the density of particles in the morning sun.
What can I do to identify and fix the excessive dust/air quality? Are there tools, a likely suspect, or a professional service that I need to source?
I tend to start simple and work my way up from there.
How humid is your air? Try adding cool mist humidifiers to your rooms and giving it a few days. That should help settle the dust, and help with breathing. If that doesn't stop the breathing issues, I would take a trip to the doctor to rule out any new medical issues and then start looking at investing in beefier home filtration systems. There are several options from store bought purifiers you place in a corner to filtration systems. Hope you feel better and get the dust under control!
The biggest culprit is likely environmental: your dry Colorado mountain air and low humidity. We have the same problem south of you in New Mexico. Raising your interior humidity will help a lot. There are several approaches, ranging from using a humidifier constantly (cheap up front, expensive to run over time) to sealing your house up airtight and using an ERV system to bring in fresh air and exhaust house air (expensive up front, cheap to run over time).
Electrostatic filters and air purifiers will help too, and falls into the category of "expensive to run over time." High maintenance, too.
Another possibility is that the contractor didn't do a very good job with the attic floor air sealing and the dust from the cellulose (it is basically dust, after all) is making it into the house. Likely entrance methods: