A ductless mini split system is composed of an indoor air handler/evaporator (fan coil), and outdoor condensing unit and an approximate 2.5-3″ conduit that accommodates the power (wiring), refrigerant line sets and a PVC condensate line (drain). s an indoor fan, referred to as the head, and an outdoor compressor unit. Many styles of air handler/evaporator (fan coil) are readily available depending upon your projects needs. Ductless units can be either 1:1 Single mini-split systems or Multi-split systems that can heat/cool multiple rooms.