It is the annual change of your filters a day. Daphne changes her filters once every 4 months because she likes to stay up on that maintenance. Daphne has a pile of brand new air filters which she opened and placed in a stack on her basement floor. It’s about a year’s worth. She opens them because when she does the change, Daphne doesn’t want to spend time opening them and in this way she can rapidly do the change. She used to have a Heating and A/C worker come to her beach house and do this but he gave her a lesson on how to do this myself so she can save money. Daphne loved that about the Heating and A/C company around here, they regularly went above and beyond to look out for their customers. The last few days everything in her beach house started to smell so bad. Daphne didn’t know where it was coming from but then thought maybe something died and it was in her heating vents. She had to phone the Heating and A/C company and they sent out a heating and cooling worker. After he examined it, he said the smell was cat pee. Daphne was confused at first because her cat wouldn’t have done that, would she? She inspected the pile of air filters on the basement floor and they all smelled. It was disgusting and she was disgusted with her kitty. The Heating and A/C worker updated the air filters Daphne had and told her she should store them anywhere else going forward. She learned a crucial lesson that day. Don’t leave your air filters on the ground, you never guess if your cat will pee on them.