The thermal systems of commercial vehicles are changing to
reduce operational costs and tailpipe CO₂ emissions and to address
anti-idling legislation. As these systems transition they must
recognize that waste heat from the internal combustion engine can
longer be the only means of providing hot coolant for heating. The
Unitary HPAC (Heat Pump Air Conditioner) provides the hot coolant
needed for heating in addition to cold coolant that can be used for
cooling.
The Unitary HPAC is a refrigerant system that is coupled with a
coolant system. It produces hot and cold coolant that is used to
manage the vehicles thermal needs. It has the ability to scavenge
heat from unused sources, which allows it to provide heating with
COP's (Coefficient of Performance) greater than 1.
The Unitary HPAC can be applied to any vehicle that does not
have enough hot coolant available for heating purposes. When
applied to a heavy-duty truck it would provide heating and cooling
for the sleeper cab without needing to run the engine. When applied
to a hybrid vehicle it improves the electric drive range and
reduces fuel consumption costs.
This paper will explain what a Unitary HPAC system is and show
how it can be applied to commercial vehicles.