Which of the following describes a split HVAC system?

A split HVAC system is characterized by having distinct units for heating and cooling that are divided between indoor and outdoor locations. This design effectively allows for efficient regulation of temperature and airflow within a building. The outdoor unit typically houses the condenser and compressor, while the indoor unit contains the evaporator and may include additional components such as an air handler or blower.

This separation enables the system to operate more efficiently, as it can utilize the outdoor environment for energy exchange during both heating and cooling processes. By separating the components, a split system also reduces noise inside the living space, since the noisy compressor is situated outside. Furthermore, the outdoor unit can be less obtrusive and allows for more flexibility in the placement of the indoor units.

The other options do not accurately define a split HVAC system: a system with all components in one location describes a packaged unit; a system using only electric heating does not encompass the wide range of energy sources that split systems can utilize; and a portable system suggests mobility rather than the fixed installation typically associated with split systems.