The Unitary HPAC (Heat Pump Air Conditioner) System has been
developed to enable a heat pump system in passenger vehicles.
Unitary HPAC uses technology of reversing the coolant instead of
refrigerant to distribute heat from where it is generated to where
it is needed. Integrating this system in a plug-in hybrid vehicle
reduces the energy required by the heating and air conditioning
system, reducing the grams of CO₂ per mile by up to 25%.
Although this system can be applied to any passenger vehicle, it
is most beneficial to hybrid and electric vehicles, because it
provides an additional source of hot coolant. These vehicles
provide less waste heat than conventional internal combustion
engine vehicles so they must rely on electric heaters to provide
the heat needed for comfort. The electric heaters are an energy
draw that reduces the electric drive range. The Unitary HPAC system
will extend the electric range significantly. In addition to
maintaining passenger comfort in cooling mode, heat can be removed
from the battery, inverter, and electronics with coolant and
directed to the passenger compartment.
This paper will use a plug-in hybrid vehicle to demonstrate the
operation of the Unitary HPAC. It will show how the Unitary HPAC
can significantly reduce refrigerant charge and provide passenger
comfort with less energy.