Air Handler Units (or AHU's for short) are a relatively new addition to the traditional Mini split world. They function exactly like some older systems in that they attach directly to existing duct work, however they have been updated with high efficiency coils and fin packs, allowing for much higher energy conservation and higher level SEER ratings. These newer, updated AHU can be combined with other mini split indoor components in some configurations to create a highly effective residence wide comfort system.