I’ve been having an ongoing VOC issue in my house, it creates a burning sensation in my nose and throat but no odors seem to be present. This issue just started happening about 4 weeks ago. It has quite odd spikes and low points. Nothing has changed in the house as far as furniture or construction goes. I’ve had 3 AC techs out and they all confirmed there are no leaks and no abnormalities in the ducts/returns or on the inside of the unit. The unit has no problem cooling. I have attempted fogging the unit and ducts with mold remediation spray, cleaning the coil, and cleaning the condensate drain. When I leave the unit off for an extended period of time the levels will reach 2500 ppb and stay there. I’m at a loss for what could be causing this issue and most companies in my area do not offer air quality testing for VOC purposes. I bought a 2nd monitor that shows results consistent with this one. Any recommendations for things to look for or additional diagnosis steps I can take?