Which energy-efficient measure is primarily used for zone air conditioning?

Heat pumps are recognized for their efficiency in zone air conditioning because they can both cool and heat spaces by transferring heat rather than generating it. This allows for targeted temperature control in specific areas of a building (zones), which is key in optimizing energy use. Heat pumps operate with high efficiency, often utilizing a fraction of the energy required by traditional cooling systems.

They can be used in various configurations, such as ductless mini-splits, which enable precise control over individual zone temperatures without the need for extensive ductwork. This makes them ideal for zones within larger spaces or buildings, providing both heating and cooling as needed while minimizing energy consumption.

In contrast, central air conditioning systems are designed to cool an entire space uniformly rather than facilitate zone-specific temperature adjustments. Meanwhile, evaporative cooling is typically effective in dry climates and does not serve the purpose of effective zone conditioning in various environmental conditions. Radiant heating is more focused on heating surfaces rather than air conditioning and does not address cooling needs. Hence, heat pumps stand out as the primary choice for energy-efficient zone air conditioning.