VRF/V systems can reduce HVAC energy consumption in at
least three ways. They have high part-load efficiencies be-
cause they consist of multiple compressors, including vari-
able speed compressors. Consequently, a typical dual com-
pressor system can operate at 21 capacity steps. HVAC systems
usually operate at between 30% and 70% of their maximum
capacity. VRF/V systems have high efficiencies in this range
and, thus, achieve excellent seasonal energy efficiencies.
VRF/V systems also provide effective zone control because
they have many evaporator units. The system can turn off indi-
vidual indoor units in locations that do not need cooling or
heating while continuing to operate efficiently. Relative to
all-air systems, VRF/V systems use less energy to distribute
heating and cooling to conditioned spaces. Finally, VRF/V
systems can recover heat in buildings that require simulta