1st off, my basement unit stopped blowing cold air last night. Having some experience with a window unit I checked the filter. Filter was clogged and the Condenser(?) was iced up on both sides and not allowing air to flow through, probably caused by the dirty filter right? Size is 16"X20"X1". What is a good filter replacement? This looked like it was constructed of a weaved fiberglass. I know here at work we have a pleated(?) filter.

Also, I noticed that cool air was leaking out small little holes in and around the unit....should those be sealed up with tape?

The upstairs unit is in the attick. I checked the filter there and it looked clean but the size is 16"X25"X1" and it was crushed to fit. I measured the opening and the 16" wide was more like 15" 13/16's of an inch. Should this be rounded down to say a 15.75" Filter?

Sorry for the newb questions but this is my first experience with Central Air systems.