1. A method of controlling air conditioning units of a restaurant, comprising the steps of: during a first period of time during which a public-accessible occupied space is closed, activating a first air conditioning unit to provide a cooling flow of air to said occupied space, during said first period of time, activating a transfer air control to permit transfer of air from said occupied space to a production space where at least one exhaust hood is located; during a second period of time, which follows said first period of time, said second period of time being one during which said occupied space is open, activating a second air conditioning unit to provide a cooling flow of air to said production space.