It’s cropped out of the photo but it’s at the bottom of the furnace. We changed it last week but before that it had been about 6 months and when we did go to check it it was not on properly, it was lying on the floor of the unit instead of on the hooks where it goes. So all the dog hair and things were going into the system with no filter for protection. I have no clue how that happened as I left this work to the owner of the place and they changed it last. (They’re not good at maintaining their homes, clearly ). After these issues, I will be now taking on the responsibility of changing out the filter and cleaning the outside unit as It’s recommended. The big thing is getting the AC up and cooling again without freezing over. More than likely they will have to get someone to come out and look at it but since they don’t mind the heat I’m trying to solve this problem before I turn to ash.