There is nothing that comes even close when dealing with indoor contaminants. I am talking about those that can’t even be identified. Persistent, stubborn and sneaky, most of the time combination of few different sources, one day you clearly smell them all over and next they’re gone… just so they can return day after in the middle of the party celebrating closure of odor problem book. And every person you ask for a help describes the odor in completely different way. Of course, air movement, pressures, temperature and humidity all affect the intensity and composition. No matter how hard you try to control those parameters in order to make some sense of it, mother nature inevitably interferes and decides to shuffle things around even indoors as well, as hardly any structure is air tight. Think a 30 or more year old house that has 20-30% of leakiness average. And here you are trying to create pressure differential of up to 10 Pa between two sections of the house. Good luck!
If it is your lucky day you’ll manage to solve the problem without having to have half of the house torn down before exposing the culprit. So please people, call me only if you forget to close a lid on your paint can in the closet, if your garage is attached to the house and you’re idling 10 minutes in it to warm up your car every morning, or if you’re cooking 4 meals a days with a range hood fan motor seized…you got the picture