Packaged Terminal Air Conditioners another name is PTAC or wall packs. used widely in commercial applications. big houses in North America. because it is easily to install and correspondent with the frame structures of houses there, so it is widely used.. Packaged Terminal Air Conditioners another name is PTAC or wall packs. used widely in commercial applications. big houses in North America. because it is easily to install and correspondent with the frame structures of houses there, so it is widely used..