Heat pumps transfer heat between the indoors and the outdoors, providing warmth in winter and cooling in summer. Their indoor units, the parts that come in contact with the air inside the home, are of two general types. Ductless heads are attached to walls or ceilings.

They pull air directly from the space and discharge heated or cooled air through louvers or grilles on the unit itself. Ducted air handlers are usually concealed in attics, basements, or mechanical rooms; they use ductwork to distribute conditioned air to the living space.

Whether ducted or ductless, each indoor unit is connected to an outdoor unit by communication wires and refrigerant pipes. Each ductless head or ducted air handler contains a fan, heat exchanger, condensate drain, and electronics. The outdoor unit has its own heat exchange coil, fan, and control circuits.

It also contains a compressor that drives refrigerant movement through the system, with valves to control its direction and flow. Some outdoor units are designed to pair with a single indoor unit. Others can support between two and eight indoor units, which can be ducted, ductless, or a mix of the two.

Heat pumps using ducted air handlers have long been common in the southern U.S. In the last few decades, improved performance in low temperatures has led to the adoption of heat pumps in more northerly regions.

Ductless heads dominated the initial wave of cold-climate heat pumps, and in northern states, public perception of heat pumps is based largely on ductless systems. As the market for heat pumps has grown, manufacturers have expanded their offerings to include ductless heads and ducted air handlers suitable for all climate zones.

Should you go with a ducted, ductless, or mixed design? Which option makes sense will depend on several factors: heating and cooling…