I hope this resolves the issue

The HVAC tech guessed that there used to be a giant family of rats living in the house, plus although they were gone there was still a lot of mouse feces plus hair in the HVAC duct

For a while I was doing easily well financially. I was making a killing on the crypto markets, plus then investing my profits into real estate. When the crypto markets crashed, I had to start selling off my other holdings as fast as I could so I wouldn’t go bankrupt, however long story short, I now live in one of my old rental properties, which is easily the last thing in the world I still own. I have no crypto, I have easily little money, plus instead of living in a mansion I live in a small, foul-smelling house on the lake. The air quality in this house is regularly a little bit unusual, even though the heating plus cooling systems labor perfectly. I began to suppose that some critter had crawled into the HVAC duct plus died, so I called a local company to perform an inspection. It turns out that I was right, plus the HVAC tech found evidence of numerous critters in my attic, plus in the ventilation plan itself. Thankfully there were no critters living in my HVAC ducts currently, however based on the evidence there used to be a huge infestation. The HVAC tech guessed that there used to be a giant family of rats living in the house, plus although they were gone there was still a lot of mouse feces plus hair in the HVAC duct. If the rodents were still there it would have been a much larger ordeal, however instead all I needed was a deep cleaning of the HVAC duct plus all of the air vents, which should resolve the issue.
SEER ratings