Smell/odor in trailer

I'm of the opinion it's the formaldehyde you are still smelling. My Outback is 3 years old. We've towed it many thousands of miles and sleep in it almost every night, especially in the summer. We use it a lot. We also keep it clean. We are not smokers, and other than pop-corn in the microwave or a coffee pot, we've never cooked inside either. (we have used the oven a few times, but clean it after every use if it needs it or not). So, even after 3 years, if the camper is closed up for a few days and then we open it, it STILL has that new camper smell. Not strong, but a faint smell. I don't think it's formaldehyde, I do think it's still the smell of the fibers in the carpet (as it's never been shampooed, or the smell of the couch or the cloth on the windows, or a combination of everything. (yes... after 3 years).

So I lean toward the "new camper smell" is still lingering. Possible solution? If you can keep your windows slightly cracked open and keep your roof vents open, it will help keep air circulating inside the camper. The smell may never go away, but at last the fresh air coming into the camper will continue to air the smells out so when you open the door, you might not smell it any more.