First, let me state this is not a DIY repair question, but just a question in general. My unit has a ceiling air unit that appears kind of old. It has a drain pan/cover around the coils. Lately it has been filling with water (which I'm 99% sure is due to the higher than normal humidity we're having lately) but is not draining. Now, I am not looking for repair instructions here, but just want to know where the drain might be located on this type of unit, as I have never seen one like it before. There is a plastic pipe on the building exterior that I'm assuming drains from somewhere. I have included pictures, any help in finding where this drain might be located is appreciated. Thanks.