High velocity split-system heating and air conditioning has the unique feature of small diameter ductwork. This makes the system ideal for adding air conditioning (and heating) to older multi-story homes where the larger diameter ductwork of standard central air conditioning is often prohibitive due to space restrictions between the walls.

High velocity systems consist of a special type of indoor equipment called an air handler, outdoor equipment (any standard either air conditioner condenser or heat pump), a line set of pipes to connect the indoor and outdoor equipment together, special narrow diameter ductwork which connects to the indoor equipment to transfer the heated and cooled air throughout the home, and a standard thermostat to control the system.

High-velocity systems may also ensure a drier, more comfortable environment than that provided by conventional air conditioning due to an air circulation method called aspiration. By discharging cold air at a high-velocity from strategic locations (such is in a corner or next to a wall), high-velocity systems create an intermingling of air in the room to give a complete and thorough circulation.