Hey, you've seen my boss'es handiwork!?! He must really get around. He's been installing and maintaining some systems for 25 years or more and even takes on the task of changing the filters a couple times per year on some of them. Well, if you go to do service or a changeout on these systems, there are piles of dirty filters lying everywhere. This is especially maddening in a wet crawl space where the mold factor is a respiratory nightmare. I once made the mistake of making rude comments about whoever had been changing the filters out without realizing that it was him. I think I hurt his feelings or something . This kind of stuff is just plain lazy and inexcusable, even if it's mostly harmless. You carried a filter to the AH/furnace, so why not carry the dirty one back out? He and I just don't think and work alike at all. Seeing this pile of filters reminded me of how many piles I've come across. It is good to know that filters are being changed, but why can't they take the old one to the trash!