Ductless systems refer to heating and cooling solutions that do not require ductwork to distribute air. Instead, they use individual units installed in different rooms or zones, allowing for targeted temperature control. This can lead to increased energy efficiency and comfort, as each unit can be adjusted according to specific needs. These systems often include mini-split air conditioners or heat pumps, which consist of an outdoor compressor and one or more indoor air-handling units. Ductless systems are popular in homes without existing ductwork and can be a great option for renovations or additions.