We just moved into a condo unit with ZoneAire Electric Heat Pumps. I have a general question about PTACs. On a cold/windy day are you suppose to feel a draft at the bottom of the unit when it is off and the vent close button is suppressed? The unit is about 15 years old, do you think the vent is broken or is the thing just too old? All four units in my apartment is like that.
If we upgrade to an efficient model, will I still feel a draft when the PTAC unit is off?

Thanks for your input.