Being an apartment dweller my entire life.. For many years now, if I move, the new place immediately gets new heavy duty (read $5 a pop) AC duplex all around the apartment. Most apartments the duplex are NEVER replaced unless they actually physically fail.SO I suggest same for moving into any new to you dwelling. Most likely new old the place has junk duplex. (though if you move every year??? (I tend to stay put. Previous 17 years, current 11 years and growing...)Geoff's suggestion of cleaning the plugs and duplex anywhere around also good idea (33 posts back) I use the Caig 'Red' cleaner conditioner for stock duplex around the apartment.