I'm renting and in this condo, they have an AC unit mode: RCBA-3765AS17, SERIAL: M4495. I feel really silly asking this question, but I can't find where the filter is actually located. Can someone please help me w/that? I know it's a permanent one that needs to be washed periodically, but that's all the information I have.

If there is one it is usually in the return air area. Did you ever think of asking the owner? They probably know.

I'm renting and in this condo, they have an AC unit mode: RCBA-3765AS17, SERIAL: M4495. I feel really silly asking this question, but I can't find where the filter is actually located. Can someone please help me w/that? I know it's a permanent one that needs to be washed periodically, but that's all the information I have.
If the filter is not in the furnace itself assuming it's a central HVAC, then the filter is most likely located in the cold air return duct.