That opens a thought. I was having some breathing problems in the living room of my trailer. Finally found the problem, when I opened the window AC, and it was full of mold slime. The HO place in question does have central AC. Might be full of mold.
Christopher A. Young Learn more about Jesus
If I had a house that I thought had these problems, long before I moved out or started filtering, venting, etc., I would get a professional company to come in and do air samples. I don't know what it costs, but I would bet for a few hundred bucks they would find out what exactly is or isn't in the air.
As Norminn points out, it *could* be a lot of things. But since Stormin can't smell it and we don't even have a description of what it smells like, I sure wouldn't be trying to use fresh air to solve an unknown problem. To the list already suggested, I'd add mold and maybe it was a former meth lab.....