Ductless systems are a fantastic and flexible way to heat and cool almost any sized space. They come in a variety of sizes and styles, so they can fit in almost every home. Traditionally, HVAC systems used ducts to deliver conditioned air through the house. Ductless systems don’t use any duct work at all. All that is needed is one or more indoor heads, one outdoor unit and one electrical circuit for the outdoor unit. One outdoor unit can power and control several heads at once.