Our grown son has moved back in with usâ€¦ With the recession going on he lost his job plus has been having a lot of trouble finding a new job. Our home has a nice sizable basement so both of us allowed him to turn that into his own bachelor pad for the time being. After all, the basement is a finished basement. The Heating, Ventilation & A/C vents go down there. It even has its own little washroom. In truth, both of us obtained this apartment 2 years ago because both of us were planning to turn the basement into an in-law suit for our mother-in-law. Sadly, she passed away before this could happen. So both of us were ecstatic that our son could use it. The people I was with and I were even more ecstatic when our son got a job toiling at a dairy farm a few months after he moved in. The problem started shortly thereafter. It seems that no matter where I am in the apartment I can odor cow crap. At first I thought it was because of dirty laundry but it persisted even after I did all of the laundry. It wasn’t until Last month that I figured out the problem. The intake vent for the whole home Heating, Ventilation & A/C system is in the basement. Our son has been putting his dirty, nasty boots on a shelf right in front of the intake vent. No wonder the whole apartment odors. I changed the filter plus moved the shelf outdoors. Then I washed all of the carpets downstairs. From now on, the boots are to stay outside of the house; Period. I might have to get our HVAC duct cleaned now though. I can still odor the odor. However, it could be in our mind.