HEATING, VENTILATING, AND AIR CONDITIONING SYSTEM WITH AN EXHAUST GAS THERMAL ENERGY EXCHANGER

A heating, ventilating, and air conditioning system for a vehicle has a control module including a housing having an air flow conduit formed therein. An evaporator core is disposed in the air flow conduit, wherein at least a portion of the evaporator is configured to receive a first fluid from a first fluid source therein. An internal thermal energy exchanger configured to receive a second fluid from a second fluid source is disposed in the air flow conduit downstream of at least a portion of the evaporator core and upstream of a blend door disposed in the air flow conduit. The internal thermal energy is in thermal energy exchange relationship with an exhaust gas system of the vehicle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1shows a heating, ventilating, and air conditioning (HVAC) system10according to an embodiment of the invention. The HVAC system10typically provides heating, ventilation, and air conditioning for a passenger compartment of a vehicle (not shown). The HVAC system10includes a control module12to control at least a temperature of the passenger compartment.

The module12illustrated includes a hollow main housing14with an air flow conduit15formed therein. The housing14includes an inlet section16, a mixing and conditioning section18, and an outlet and distribution section (not shown). In the embodiment shown, an air inlet22is formed in the inlet section16. The air inlet22is in fluid communication with a supply of air (not shown). The supply of air can be provided from outside of the vehicle, recirculated from the passenger compartment of the vehicle, or a mixture of the two, for example. The inlet section16is adapted to receive a blower wheel (not shown) therein to cause air to flow through the air inlet22. A filter (not shown) can be provided upstream, in, or downstream of the inlet section16in respect of a direction of flow through the module12if desired.

The mixing and conditioning section18of the housing14is configured to receive an evaporator core24and a heater core28therein. As shown, at least a portion of the mixing and conditioning section18is divided into a first passage30and a second passage32. In particular embodiments, the evaporator core24is disposed upstream of a selectively positionable blend door34in respect of the direction of flow through the module12and the heater core28is disposed in the second passage32downstream of the blend door34in respect of the direction of flow through the module12. A filter (not shown) can also be provided upstream of the evaporator core24in respect of the direction of flow through the module12, if desired.

The evaporator core24of the present invention, shown inFIGS. 1-2, is a multi-layer louvered-fin thermal energy exchanger. In a non-limiting example, the evaporator core24has a first layer40, a second layer42, and a third layer44arranged substantially perpendicular to the direction of flow through the module12. Additional or fewer layers than shown can be employed as desired. The layers40,42,44are arranged so the second layer42is disposed downstream of the first layer40and upstream of the third layer44in respect of the direction of flow through the module12. It is understood, however, that the layers40,42,44can be arranged as desired. The layers40,42,44can be bonded together by any suitable method as desired such as brazing and welding, for example.

Each of the layers40,42,44of the evaporator core24includes an upper first fluid manifold46,48,50and a lower second fluid manifold52,54,56, respectively. A plurality of first tubes58extends between the fluid manifolds46,52of the first layer40. A plurality of second tubes60extends between the fluid manifolds48,54of the second layer42. A plurality of third tubes62extends between the fluid manifolds50,56of the third layer44. In particular embodiments, each of the first upper fluid manifolds46,48,50is an inlet manifold which distributes the fluid into at least a portion of the respective tubes58,60,62and each of the second lower fluid manifolds52,54,56is an outlet manifold which collects the fluid from at least a portion of the respective tubes58,60,62.

Each of the tubes58,60,62is provided with louvered fins64disposed therebetween. The fins64abut an outer surface of the tubes58,60,62for enhancing thermal energy transfer of the evaporate core24. Each of the fins64defines an air space68extending between the tubes58,60,62. The tubes58,60,62of the evaporator core24can further include a plurality of internal fins (not shown) formed on an inner surface thereof. The internal fins further enhance the transfer of thermal energy of the evaporator core24. It is understood, however, that the evaporator core24can be constructed as a finless thermal energy exchanger if desired.

In a particular embodiment, the layers40,42of the evaporator core24, shown inFIG. 1, are in fluid communication with a first fluid source70via a conduit72. The first fluid source70includes a prime mover74such as a compressor or a pump, for example, to cause a first fluid to circulate therein. Each of the layers40,42is configured to receive a flow of the first fluid from the first fluid source70therein. The first fluid absorbs thermal energy to condition the air flowing through the HVAC module12when a fuel-powered engine of the vehicle, and thereby the prime mover74, is in operation. As a non-limiting example, the first fluid source70is a refrigeration circuit, and the first fluid is a refrigerant such as R134a, HFO-1234yf, AC-5, AC-6, and CO2, for example. A valve76can be disposed in the conduit72to selectively control the flow of the first fluid therethrough.

The HVAC system10includes an internal thermal energy exchanger78in fluid communication with a second fluid source80via a conduit82. The second fluid source80includes a prime mover84(e.g. an electrical coolant pump) to cause a second fluid to circulate through the internal thermal energy exchanger78. As illustrated, the internal thermal energy exchanger78is the layer44of the evaporator core24. In other embodiments, the layers40,44of the evaporator core24are in fluid communication with the first fluid source70and the internal thermal energy exchanger78is the layer42of the evaporator core24in thermal energy exchange relationship with the second fluid source80. In yet other certain embodiments, only the layer40of the evaporator core24is in fluid communication with the first fluid source70and the internal thermal energy exchanger78is the layers42,44of the evaporator core24in thermal energy exchange relationship with the second fluid source80.

The internal thermal energy exchanger78is configured to receive a flow of the second fluid from the second fluid source80therein. The second fluid absorbs or releases thermal energy to condition the air flowing through the HVAC module12. A valve86can be disposed in the conduit82to selectively control the flow of the second fluid therethrough. As a non-limiting example, the second fluid source80is a fluid reservoir containing a phase change material (PCM) therein. Those skilled in the art will appreciate that the phase change material can be any suitable material that melts and solidifies at predetermined temperatures and is capable of storing and releasing thermal energy such as organic, inorganic, eutectic and ionic liquids (e.g. a paraffin, a paraffin wax, an alcohol, water, a polygycol, a glycol), and the like, or any combination thereof, for example. The phase change material can also be impregnated with a thermally conductive material such as graphite powder, for example, to further enhance the transfer of thermal energy. As another non-limiting example, the second fluid source80is a fluid reservoir containing a coolant therein. As another non-limiting example, the second fluid source80is a fluid reservoir containing a phase change material coolant such as CryoSolplus, for example, therein. As yet another non-limiting example, the second fluid source80is an external thermal energy exchanger (e.g. a shell and tube heat exchanger, a chiller, etc.) which includes a phase change material disposed therein and/or is in fluid communication with at least one other vehicle system.

In certain embodiments, the internal thermal energy exchanger78is in thermal energy exchange relationship with an exhaust gas system88of the vehicle via an external thermal energy exchanger89. Those skilled in the art will appreciate that the external thermal energy exchanger89can be any suitable thermal energy exchanger such as an exhaust gas recirculation (EGR) thermal energy exchanger, for example. As illustrated, the external thermal energy exchanger89is in fluid communication with the internal thermal energy exchanger78and configured to receive, through a conduit90, a flow of a working fluid therein. A valve91can be disposed in the conduit90to selectively control the flow of the working fluid therethrough. The external thermal energy exchanger89is also in fluid communication with the exhaust gas system88and configured to receive, through a conduit92, a flow of an exhaust gas therein. As shown, the flow of the exhaust gas through the external thermal energy exchanger89is counter to the flow of the working fluid therethrough. It is understood that the flow of the exhaust gas through the external thermal energy exchanger89can be in any suitable flow direction in respect of the flow of the working fluid as desired such as concurrent flow direction and a cross-flow direction, for example. A valve93can be disposed in the conduit92to selectively control the flow of the exhaust gas therethrough. The external thermal energy exchanger89facilitates a transfer of thermal energy from the exhaust gas to heat the working fluid, especially when the fuel-powered engine of the vehicle is in operation. The exhaust gas is typically at a temperature in a range of about 400° C. to about 1000° C. As such, the working fluid is heated very rapidly and may heat the air flowing through the air flow conduit15before the fuel-powered engine reaches a normal operating temperature. Accordingly, a size and capacity of the heater core28may be decreased in respect of heater cores of the prior art, which may facilitate a decrease in air side pressure drop during heating modes of the HVAC system10, as well as an increase in available package space within the control module12.

As shown, the heater core28is in fluid communication with a third fluid source95via a conduit96. The heater core28is configured to receive a flow of a third fluid from the third fluid source95therein. The third fluid source95can be any conventional source of heated fluid such as the fuel-powered engine or a battery system of the vehicle, for example, and the third fluid can be any conventional fluid such as a phase change material, a coolant, or a phase change material coolant, for example. A valve97can be disposed in the conduit96to selectively control the flow of the third fluid therethrough. The heater core28is configured to facilitate a release of thermal energy from the third fluid to heat the air flowing therethrough when the fuel-powered engine of the vehicle is in operation. As a non-limiting example, the second fluid from the second fluid source80, the working fluid from the external thermal energy exchanger89, and the third fluid from the third fluid source95are the same fluid types. It is understood, however, that the second fluid from the second fluid source80, the working fluid from the external thermal energy exchanger89, and the third fluid from the third fluid source95may be different fluid types if desired.

In operation, the HVAC system10conditions air by heating or cooling the air, and providing the conditioned air to the passenger compartment of the vehicle. Air from the supply of air is received in the inlet section16of the housing14in the air inlet22and flows through the housing14of the module12.

In each operating mode of the HVAC system10, the blend door34may be positioned in one of a first position permitting air from the evaporator core24and the internal thermal energy exchange78to only flow into the first passage30, a second position permitting the air from the evaporator core24and the internal thermal energy exchanger78to only flow into the second passage32, and an intermediate position permitting the air from the evaporator core24and the internal thermal energy exchanger78to flow through both the first passage30and the second passage32and through the heater core28

When the fuel-powered engine of the vehicle is in operation and the HVAC system10is operating in either a cooling mode or a cold thermal energy charge mode, the first fluid from the first fluid source70circulates through the conduit72to the evaporator core24. Additionally, the second fluid from the second fluid source80circulates through the conduit82to the internal thermal energy exchanger78. However, the valve91is closed to militate against the circulation of the working fluid from the external thermal energy exchanger89through the conduit90to the internal thermal energy exchanger78, the valve93is closed to militate against the circulation of the exhaust gas from the exhaust gas system88through the conduit92to the external thermal energy exchanger89, and the valve97is closed to militate against the circulation of the third fluid from the third fluid source95through the conduit96to the heater core28. Accordingly, the air from the inlet section16flows into the evaporator core24where the air is cooled to a desired temperature by a transfer of thermal energy from the air to the first fluid from the first fluid source70. The conditioned air then flows from the evaporator core24to the internal thermal energy exchanger78. As the conditioned air flows through the internal thermal energy exchanger78, the conditioned air absorbs thermal energy from the second fluid. The transfer of thermal energy from the second fluid to the conditioned air cools the second fluid. The second fluid then flows to the second fluid source80and absorbs thermal energy to cool or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source80. The conditioned air then exits the internal thermal energy exchanger78and is selectively permitted by the blend door34to flow through the first passage30and/or the second passage32. It is understood, however, that in other embodiments the valve97is open, permitting the third fluid from the third fluid source95to circulate through the conduit96to the heater core28, and thereby demist the conditioned air flowing through the second passage32.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10is operating in an alternative cooling mode, the first fluid from the first fluid source70circulates through the conduit72to the evaporator core24. However, the valve86is closed to militate against the circulation of the second fluid from the second fluid source80through the conduit82to the internal thermal energy exchanger78. Additionally, the valve91is closed to militate against the circulation of the working fluid from the external thermal energy exchanger89through the conduit90to the internal thermal energy exchanger78, the valve93is closed to militate against the circulation of the exhaust gas from the exhaust gas system88through the conduit92to the external thermal energy exchanger89, and the valve97is closed to militate against the circulation of the third fluid from the third fluid source95through the conduit96to the heater core28. Accordingly, the air from the inlet section16flows into the evaporator core24where the air is cooled to a desired temperature by a transfer of thermal energy from the air to the first fluid from the first fluid source70. The conditioned air then flows from the evaporator core24to the internal thermal energy exchanger78. As the conditioned air flows through the internal thermal energy exchanger78, the temperature of the conditioned air is relatively unaffected. The conditioned air then exits the internal thermal energy exchanger78and is selectively permitted by the blend door34to flow through the first passage30and/or the second passage32. It is understood, however, that in other embodiments the valve97is open, permitting the third fluid from the third fluid source95to circulate through the conduit96to the heater core28, and thereby demist the conditioned air flowing through the second passage32.

When the fuel-powered engine of the vehicle is not in operation and the HVAC system10is operating in an engine-off cooling mode, the first fluid from the first fluid source70does not circulate through the conduit72to the evaporator core24. Additionally, the valve91is closed to militate against the circulation of the working fluid from the external thermal energy exchanger89through the conduit90to the internal thermal energy exchanger78, the exhaust gas from the exhaust gas system88does not circulate through the conduit92to the external thermal energy exchanger89, and the third fluid from the third fluid source95does not circulate through the conduit96to the heater core28. However, the second fluid from the second fluid source80circulates through the conduit82to the internal thermal energy exchanger78. Accordingly, the air from the inlet section16flows through the evaporator core24where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24to the internal thermal energy exchanger78. As the air flows through the internal thermal energy exchanger78, the air is cooled to a desired temperature by a transfer of thermal energy from the air to the second fluid from the second fluid source80. The conditioned air then exits the thermal energy exchanger78and is selectively permitted by the blend door34to flow through the first passage30and/or the second passage32.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10is operating in a heating mode, the valve76is closed to militate against the circulation of the first fluid from the first fluid source70through the conduit72to the evaporator core24. Similarly, the valve86is closed to militate against the circulation of the second fluid from the second fluid source80through the conduit82to the internal thermal energy exchanger78. Additionally, the valve91is closed to militate against the circulation of the working fluid from the external thermal energy exchanger89through the conduit90to the internal thermal energy exchanger78and the valve93is closed to militate against the circulation of the exhaust gas from the exhaust gas system88through the conduit92to the external thermal energy exchanger89. However, the third fluid from the third fluid source95circulates through the conduit96to the heater core28. Accordingly, the air from the inlet section16flows through the evaporator core24and the internal thermal energy exchanger78where a temperature of the air is relatively unaffected. The unconditioned air then exits the evaporator core24and the internal thermal energy exchanger78and is selectively permitted by the blend door34to flow through the first passage30and/or the second passage32through the heater core28to be heated to a desired temperature.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10is operating in an alternative heating mode, the valve76is closed to militate against the circulation of the first fluid from the first fluid source70through the conduit72to the evaporator core24. Similarly, the valve86is closed to militate against the circulation of the second fluid from the second fluid source80through the conduit82to the internal thermal energy exchanger78. However, the working fluid from the external thermal energy exchanger89circulates through the conduit90to the internal thermal energy exchanger78and the exhaust gas from the exhaust gas system88circulates through the conduit92to the external thermal energy exchanger89. Additionally, the valve97is closed to militate against the circulation of the third fluid from the third fluid source95through the conduit96to the heater core28. Accordingly, the air from the inlet section16flows through the evaporator core24where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24to the internal thermal energy exchanger78. As the air flows through the internal thermal energy exchanger78, the air is heated to a desired temperature by a transfer of thermal energy from the working fluid from the external thermal energy exchanger89to the air flowing through the internal thermal energy exchanger78. The working fluid then flows to the external thermal energy exchanger89. In the external thermal energy exchanger89, the working fluid absorbs thermal energy from the exhaust gas to heat the working fluid. The conditioned air then exits the internal thermal energy exchanger78and is selectively permitted by the blend door34to flow through the first passage30and/or the second passage32. It is understood, however, that in other embodiments the valve97is open, permitting the third fluid from the third fluid source95to circulate through the conduit96to the heater core28, and thereby further heat the conditioned air flowing through the second passage32to a desired temperature.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10is operating in another alternative heating mode, the valve76is closed to militate against the circulation of the first fluid from the first fluid source70through the conduit72to the evaporator core24. Additionally, the valve91is closed to militate against the circulation of the working fluid from the external thermal energy exchanger89through the conduit90to the internal thermal energy exchanger78, the valve93is closed to militate against the circulation of the exhaust gas from the exhaust gas system88through the conduit92to the external thermal energy exchanger89, and the valve97is closed to militate against the circulation of the third fluid from the third fluid source95through the conduit96to the heater core28. However, the second fluid from the second fluid source80circulates through the conduit82to the internal thermal energy exchanger78. Accordingly, the air from the inlet section16flows through the evaporator core24where a temperature of the air is relatively unaffected. The unconditioned air then exits the evaporator core24and flows to the internal thermal energy exchanger78. As the air flows through the internal thermal energy exchanger78, the air is heated to a desired temperature by a transfer of thermal energy from the second fluid from the second fluid source80to the air flowing through the internal thermal energy exchanger78. The conditioned air then exits the internal thermal energy exchanger78and is selectively permitted by the blend door34to flow through the first passage30and/or the second passage32. It is understood, however, that in other embodiments the valve97is open, permitting the third fluid from the third fluid source95to circulate through the conduit96to the heater core28, and thereby further heat the conditioned air flowing through the second passage32to a desired temperature.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10is operating in an alternative heating mode or a hot thermal energy charge mode, the valve76is closed to militate against the circulation of the first fluid from the first fluid source70through the conduit72to the evaporator core24. Similarly, the valve97is closed to militate against the circulation of the third fluid from the third fluid source95through the conduit96to the heater core28. However, the second fluid from the second fluid source80circulates through the conduit82to the internal thermal energy exchanger78. Additionally, the working fluid from the external thermal energy exchanger89circulates through the conduit90to the internal thermal energy exchanger78and the exhaust gas from the exhaust gas system88circulates through the conduit92to the external thermal energy exchanger89. The working fluid mixes with the second fluid before, in, or after flowing through the internal thermal energy exchanger78. Accordingly, the air from the inlet section16flows through the evaporator core24where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24to the internal thermal energy exchanger78. As the air flows through the internal thermal energy exchanger78, the air is heated to a desired temperature by a transfer of thermal energy from the mixture of the second fluid and the working fluid to the air flowing through the internal thermal energy exchanger78. The mixture of the second fluid and the working fluid then flows to the second fluid source80and the external thermal energy exchanger89. In the second fluid source80, the mixture of the second fluid and the working fluid releases thermal energy to heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source80. In the external thermal energy exchanger89, the mixture of the second fluid and the working fluid absorbs thermal energy from the exhaust gas. The conditioned air then exits the internal thermal energy exchanger78and is selectively permitted by the blend door34to flow through the first passage30and/or the second passage32. It is understood, however, that in other embodiments the valve97is open, permitting the third fluid from the third fluid source95to circulate through the conduit96to the heater core28, and thereby further heat the conditioned air flowing through the second passage32to a desired temperature.

When the fuel-powered engine of the vehicle is not in operation and the HVAC system10is operating in an engine-off heating mode, the first fluid from the first fluid source70does not circulate through the conduit72to the evaporator core24. Additionally, the valve91is closed to militate against the circulation of the working fluid from the external thermal energy exchanger89through the conduit90to the internal thermal energy exchanger78, the exhaust gas from the exhaust gas system88does not circulate through the conduit92to the external thermal energy exchanger89, and the third fluid from the third fluid source95does not circulate through the conduit96to the heater core28. However, the second fluid from the second fluid source80circulates through the conduit82to the internal thermal energy exchanger78. Accordingly, the air from the inlet section16flows through the evaporator core24where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24to the internal thermal energy exchanger78. As the air flows through the internal thermal energy exchanger78, the air is heated to a desired temperature by a transfer of thermal energy from the second fluid from the second fluid source80to the air flowing through the internal thermal energy exchanger78. The conditioned air then exits the thermal energy exchanger78and is selectively permitted by the blend door34to flow through the first passage30and/or the second passage32.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10is operating in a recirculation heating mode or an alternative hot thermal energy charge mode, the valve76is closed to militate against the circulation of the first fluid from the first fluid source70through the conduit72to the evaporator core24. Similarly, the valve86is closed to militate against the circulation of the second fluid from the second fluid source80through the conduit82to the internal thermal energy exchanger78. Additionally, the valve91is closed to militate against the circulation of the working fluid from the external thermal energy exchanger89through the conduit90to the internal thermal energy exchanger78, the valve93is closed to militate against the circulation of the exhaust gas from the exhaust gas system88through the conduit92to the external thermal energy exchanger89, and the valve97is closed to militate against the circulation of the third fluid from the third fluid source95through the conduit96to the heater core28. Accordingly, a re-circulated air from a passenger compartment of the vehicle flows through the inlet section16, through the evaporator core24, and into the internal thermal energy exchanger78where a temperature of the air is relatively unaffected. The re-circulated air then exits the internal thermal energy exchanger78and is selectively permitted by the blend door34to flow through the first passage30and/or the second passage32. It is understood, however, that in other embodiments the valve86is open permitting the second fluid from the second fluid source80which has been heated by the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source80to circulate through the conduit82to the internal thermal energy exchanger78, the valves91,93are open permitting the working fluid from the external thermal energy exchanger89which has been heated by the exhaust gas to circulate through the conduit90to the internal thermal energy exchanger78, and/or the valve97is open permitting the third fluid from the third fluid source95to circulate through the conduit96to the heater core28, and thereby heat the re-circulated air flowing through the first passage30and/or the second passage32. It is further understood that the valve86is open permitting the second fluid to absorb thermal energy from air flowing through the internal thermal energy exchanger78, and thereby heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source80.

FIG. 3shows an alternative embodiment of the HVAC system10illustrated inFIG. 1. Structure similar to that illustrated inFIGS. 1-2includes the same reference numeral and a prime (′) symbol for clarity.

InFIG. 3, the HVAC system10′ includes a control module12′ to control at least a temperature of the passenger compartment. The module12′ illustrated includes a hollow main housing14′ with an air flow conduit15′ formed therein. The housing14′ includes an inlet section16′, a mixing and conditioning section18′, and an outlet and distribution section (not shown). In the embodiment shown, an air inlet22′ is formed in the inlet section16′. The air inlet22′ is in fluid communication with a supply of air (not shown). The supply of air can be provided from outside of the vehicle, recirculated from the passenger compartment of the vehicle, or a mixture of the two, for example. The inlet section16′ is adapted to receive a blower wheel (not shown) therein to cause air to flow through the air inlet22′. A filter (not shown) can be provided upstream, in, or downstream of the inlet section16′ in respect of a direction of flow through the module12′ if desired.

The mixing and conditioning section18′ of the housing14′ is configured to receive an evaporator core24′ and a heater core28′ therein. As shown, at least a portion of the mixing and conditioning section18′ is divided into a first passage30′ and a second passage32′. In particular embodiments, the evaporator core24′ is disposed upstream of a selectively positionable blend door34′ in respect of the direction of flow through the module12′ and the heater core28′ is disposed in the second passage32′ downstream of the blend door34′ in respect of the direction of flow through the module12′. A filter (not shown) can also be provided upstream of the evaporator core24′ in respect of the direction of flow through the module12′, if desired.

The evaporator core24′ of the present invention is a multi-layer louvered-fin thermal energy exchanger. In a non-limiting example, the evaporator core24′ has a first layer40′, a second layer42′, and a third layer44′ arranged substantially perpendicular to the direction of flow through the module12′. Additional or fewer layers than shown can be employed as desired. The layers40′,42′,44′ are arranged so the second layer42′ is disposed downstream of the first layer40′ and upstream of the third layer44′ in respect of the direction of flow through the module12′. It is understood, however, that the layers40′,42′,44′ can be arranged as desired. The layers40′,42′,44′ can be bonded together by any suitable method as desired such as brazing and welding, for example.

In a particular embodiment, the layers40′,42′ of the evaporator core24′, shown inFIG. 3, are in fluid communication with a first fluid source70′ via a conduit72′. The first fluid source70′ includes a prime mover74′ such as a compressor or a pump, for example, to cause a first fluid to circulate therein. Each of the layers40′,42′ is configured to receive a flow of the first fluid from the first fluid source70′ therein. The first fluid absorbs thermal energy to condition the air flowing through the HVAC module12′ when a fuel-powered engine of the vehicle, and thereby the prime mover74′, is in operation. As a non-limiting example, the first fluid source70′ is a refrigeration circuit, and the first fluid is a refrigerant such as R134a, HFO-1234yf, AC-5, AC-6, and CO2, for example. A valve76′ can be disposed in the conduit72′ to selectively control the flow of the first fluid therethrough.

The HVAC system10′ includes an internal thermal energy exchanger78′ in fluid communication with a second fluid source80′ via a conduit82′. The second fluid source80′ includes a prime mover84′ (e.g. an electrical coolant pump) to cause a second fluid to circulate through the internal thermal energy exchanger78′. As illustrated, the internal thermal energy exchanger78′ is the layer44′ of the evaporator core24′. In other embodiments, the layers40′,44′ of the evaporator core24′ are in fluid communication with the first fluid source70′ and the internal thermal energy exchanger78′ is the layer42′ of the evaporator core24′ in thermal energy exchange relationship with the second fluid source80′. In yet other certain embodiments, only the layer40′ of the evaporator core24′ is in fluid communication with the first fluid source70′ and the internal thermal energy exchanger78′ is the layers42′,44′ of the evaporator core24′ in thermal energy exchange relationship with the second fluid source80′.

The internal thermal energy exchanger78′ is configured to receive a flow of the second fluid from the second fluid source80′ therein. The second fluid absorbs or releases thermal energy to condition the air flowing through the HVAC module12′. A valve86′ can be disposed in the conduit82′ to selectively control the flow of the second fluid therethrough. As a non-limiting example, the second fluid source80′ is a fluid reservoir containing a phase change material (PCM) therein. Those skilled in the art will appreciate that the phase change material can be any suitable material that melts and solidifies at predetermined temperatures and is capable of storing and releasing thermal energy such as organic, inorganic, eutectic and ionic liquids (e.g. a paraffin, a paraffin wax, an alcohol, water, a polygycol, a glycol), and the like, or any combination thereof, for example. The phase change material can also be impregnated with a thermally conductive material such as graphite powder, for example, to further enhance the transfer of thermal energy. As another non-limiting example, the second fluid source80′ is a fluid reservoir containing a coolant therein. As another non-limiting example, the second fluid source80′ is a fluid reservoir containing a phase change material coolant such as CryoSolplus, for example, therein. As yet another non-limiting example, the second fluid source80′ is an external thermal energy exchanger (e.g. a shell and tube heat exchanger, a chiller, etc.) which includes a phase change material disposed therein and/or is in fluid communication with at least one other vehicle system.

In certain embodiments, the internal thermal energy exchanger78′ is in thermal energy exchange relationship with an exhaust gas system88′ of the vehicle via an external thermal energy exchanger89′. Those skilled in the art will appreciate that the external thermal energy exchanger89′ can be any suitable thermal energy exchanger such as an exhaust gas recirculation (EGR) thermal energy exchanger, for example. As illustrated, the external thermal energy exchanger89′ is in fluid communication with the internal thermal energy exchanger78′ and configured to receive, through a conduit90′, a flow of the working fluid therein. A valve91′ can be disposed in the conduit90′ to selectively control the flow of the working fluid therethrough. The external thermal energy exchanger89′ is also in fluid communication with the exhaust gas system88′ and configured to receive, through a conduit92′, a flow of an exhaust gas therein. As shown, the flow of the exhaust gas through the external thermal energy exchanger89′ is counter to the flow of the working fluid therethrough. It is understood that the flow of the exhaust gas through the external thermal energy exchanger89′ can be in any suitable flow direction in respect of the flow of the working fluid as desired such as a concurrent flow direction and a cross-flow direction, for example. A valve93′ can be disposed in the conduit92′ to selectively control the flow of the exhaust gas therethrough. The external thermal energy exchanger89′ facilitates a transfer of thermal energy from the exhaust gas to heat the working fluid, especially when the fuel-powered engine of the vehicle is in operation. The exhaust gas is typically at a temperature in a range of about 400° C. to about 1000° C. As such, the working fluid is heated very rapidly and may heat the air flowing through the air flow conduit15′ before the fuel-powered engine reaches a normal operating temperature. Accordingly, a size and capacity of the heater core28′ may be decreased in respect of heater cores of the prior art, which may facilitate a decrease in air side pressure drop during heating modes of the HVAC system10′, as well as an increase in available package space within the control module12′.

As shown, the heater core28′ is in fluid communication with a third fluid source95′ via a conduit96′. The heater core28′ is configured to receive a flow of a third fluid from the third fluid source95′ therein. The third fluid source95′ can be any conventional source of heated fluid such as the fuel-powered engine or a battery system of the vehicle, for example, and the third fluid can be any conventional fluid such as a phase change material, a coolant, or a phase change material coolant, for example. A valve97′ can be disposed in the conduit96′ to selectively control the flow of the third fluid therethrough. The heater core28′ is configured to facilitate a release of thermal energy from the third fluid to heat the air flowing therethrough when the fuel-powered engine of the vehicle is in operation.

A fourth fluid source102is in fluid communication with the external thermal energy exchanger89′ via a conduit104. The fourth fluid source102is configured to receive a flow of a fourth fluid therein. In certain embodiments, the fourth fluid is the working fluid from the external thermal energy exchanger89′. A valve106can be disposed in the conduit104to selectively control the flow of the fourth fluid therethrough. As a non-limiting example, the fourth fluid source102is a fluid reservoir containing a phase change material (PCM) therein. Those skilled in the art will appreciate that the phase change material can be any suitable material that melts and solidifies at predetermined temperatures and is capable of storing and releasing thermal energy such as organic, inorganic, eutectic and ionic liquids (e.g. a paraffin, a paraffin wax, an alcohol, water, a polygycol, a glycol), and the like, or any combination thereof, for example. The phase change material can also be impregnated with a thermally conductive material such as graphite powder, for example, to further enhance the transfer of thermal energy. As another non-limiting example, the fourth fluid source102is a fluid reservoir containing a coolant therein. As another non-limiting example, the fourth fluid source102is a fluid reservoir containing a phase change material coolant such as CryoSolplus, for example, therein. As yet another non-limiting example, the fourth fluid source102is an external thermal energy exchanger (e.g. a shell and tube heat exchanger, a chiller, etc.) which includes a phase change material disposed therein and/or is in fluid communication with at least one other vehicle system.

The external thermal energy exchanger89′ is also in fluid communication with the internal thermal energy exchanger78′ via a bypass conduit108. A valve110can be disposed in the bypass conduit108to selectively control the flow of the fourth fluid therethrough. As a non-limiting example, the second fluid from the second fluid source80′, the working fluid from the external thermal energy exchanger89′, the third fluid from the third fluid source95′, and the fourth fluid from the fourth fluid source102are the same fluid types. It is understood, however, that the second fluid from the second fluid source80′, the working fluid from the external thermal energy exchanger89′, the third fluid from the third fluid source95′, and the fourth fluid from the fourth fluid source102may be different fluid types if desired.

In operation, the HVAC system10′ conditions air by heating or cooling the air, and providing the conditioned air to the passenger compartment of the vehicle. Air from the supply of air is received in the inlet section16′ of the housing14′ in the air inlet22′ and flows through the housing14′ of the module12′.

In each operating mode of the HVAC system10′, the blend door34′ may be positioned in one of a first position permitting air from the evaporator core24′ and the internal thermal energy exchange78′ to only flow into the first passage30′, a second position permitting the air from the evaporator core24′ and the internal thermal energy exchanger78′ to only flow into the second passage32′, and an intermediate position permitting the air from the evaporator core24′ and the internal thermal energy exchanger78′ to flow through both the first passage30′ and the second passage32′ and through the heater core28′

When the fuel-powered engine of the vehicle is in operation and the HVAC system10′ is operating in either a cooling mode or a cold thermal energy charge mode, the first fluid from the first fluid source70′ circulates through the conduit72′ to the evaporator core24′. Additionally, the second fluid from the second fluid source80′ circulates through the conduit82′ to the internal thermal energy exchanger78′. However, the valves91′,106,110are closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89′ and the fourth fluid source102through the respective conduits90′,104,108to the internal thermal energy exchanger78′, the valve93′ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88′ through the conduit92′ to the external thermal energy exchanger89′, and the valve97′ is closed to militate against the circulation of the third fluid from the third fluid source95′ through the conduit96′ to the heater core28′. Accordingly, the air from the inlet section16′ flows into the evaporator core24′ where the air is cooled to a desired temperature by a transfer of thermal energy from the air to the first fluid from the first fluid source70′. The conditioned air then flows from the evaporator core24′ to the internal thermal energy exchanger78′. As the conditioned air flows through the internal thermal energy exchanger78′, the conditioned air absorbs thermal energy from the second fluid. The transfer of thermal energy from the second fluid to the conditioned air cools the second fluid. The second fluid then flows to the second fluid source80′ and absorbs thermal energy to cool or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source80′. The conditioned air then exits the internal thermal energy exchanger78′ and is selectively permitted by the blend door34′ to flow through the first passage30′ and/or the second passage32′. It is understood, however, that in other embodiments the valve97′ is open, permitting the third fluid from the third fluid source95′ to circulate through the conduit96′ to the heater core28′, and thereby demist the conditioned air flowing through the second passage32′.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10′ is operating in an alternative cooling mode, the first fluid from the first fluid source70′ circulates through the conduit72′ to the evaporator core24′. However, the valve86′ is closed to militate against the circulation of the second fluid from the second fluid source80′ through the conduit82′ to the internal thermal energy exchanger78′. Additionally, the valves91′,106,110are closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89′ and the fourth fluid source102through the respective conduits90′,104,108to the internal thermal energy exchanger78′, the valve93′ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88′ through the conduit92′ to the external thermal energy exchanger89′, and the valve97′ is closed to militate against the circulation of the third fluid from the third fluid source95′ through the conduit96′ to the heater core28′. Accordingly, the air from the inlet section16′ flows into the evaporator core24′ where the air is cooled to a desired temperature by a transfer of thermal energy from the air to the first fluid from the first fluid source70′. The conditioned air then flows from the evaporator core24′ to the internal thermal energy exchanger78′. As the conditioned air flows through the internal thermal energy exchanger78′, the temperature of the conditioned air is relatively unaffected. The conditioned air then exits the internal thermal energy exchanger78′ and is selectively permitted by the blend door34′ to flow through the first passage30′ and/or the second passage32′. It is understood, however, that in other embodiments the valve97′ is open, permitting the third fluid from the third fluid source95′ to circulate through the conduit96′ to the heater core28′, and thereby demist the conditioned air flowing through the second passage32′.

When the fuel-powered engine of the vehicle is not in operation and the HVAC system10′ is operating in an engine-off cooling mode, the first fluid from the first fluid source70′ does not circulate through the conduit72′ to the evaporator core24′. Additionally, the valves91′,106,110are closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89′ and the fourth fluid source102through the respective conduits90′,104,108to the internal thermal energy exchanger78′, the exhaust gas from the exhaust gas system88′ does not circulate through the conduit92′ to the external thermal energy exchanger89′, and the third fluid from the third fluid source95′ does not circulate through the conduit96′ to the heater core28′. However, the second fluid from the second fluid source80′ circulates through the conduit82′ to the internal thermal energy exchanger78′. Accordingly, the air from the inlet section16′ flows through the evaporator core24′ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24′ to the internal thermal energy exchanger78′. As the air flows through the internal thermal energy exchanger78′, the air is cooled to a desired temperature by a transfer of thermal energy from the air to the second fluid from the second fluid source80′. The conditioned air then exits the thermal energy exchanger78′ and is selectively permitted by the blend door34′ to flow through the first passage30′ and/or the second passage32′.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10′ is operating in a heating mode, the valve76′ is closed to militate against the circulation of the first fluid from the first fluid source70′ through the conduit72′ to the evaporator core24′. Similarly, the valve86′ is closed to militate against the circulation of the second fluid from the second fluid source80′ through the conduit82′ to the internal thermal energy exchanger78′. Additionally, the valves91′,106,110are closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89′ and the fourth fluid source102through the respective conduits90′,104,108to the internal thermal energy exchanger78′ and the valve93′ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88′ through the conduit92′ to the external thermal energy exchanger89′. However, the third fluid from the third fluid source95′ circulates through the conduit96′ to the heater core28′. Accordingly, the air from the inlet section16′ flows through the evaporator core24′ and the internal thermal energy exchanger78′ where a temperature of the air is relatively unaffected. The unconditioned air then exits the evaporator core24′ and the internal thermal energy exchanger78′ and is selectively permitted by the blend door34′ to flow through the first passage30′ and/or the second passage32′ through the heater core28′ to be heated to a desired temperature.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10′ is operating in an alternative heating mode, the valve76′ is closed to militate against the circulation of the first fluid from the first fluid source70′ through the conduit72′ to the evaporator core24′. Similarly, the valve86′ is closed to militate against the circulation of the second fluid from the second fluid source80′ through the conduit82′ to the internal thermal energy exchanger78′, the valve106is closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89′ to the fourth fluid source102, and the valve97′ is closed to militate against the circulation of the third fluid from the third fluid source95′ through the conduit96′ to the heater core28′. However, the fourth fluid from the external thermal energy exchanger89′ circulates through the conduits91′,108to the internal thermal energy exchanger78′ and the exhaust gas from the exhaust gas system88′ circulates through the conduit92′ to the external thermal energy exchanger89′. Accordingly, the air from the inlet section16′ flows through the evaporator core24′ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24′ to the internal thermal energy exchanger78′. As the air flows through the internal thermal energy exchanger78′, the air is heated to a desired temperature by a transfer of thermal energy from the fourth fluid from the external thermal energy exchanger89′ to the air flowing through the internal thermal energy exchanger78′. In the external thermal energy exchanger89′, the fourth fluid absorbs thermal energy from the exhaust gas to heat the second fluid. The conditioned air then exits the internal thermal energy exchanger78′ and is selectively permitted by the blend door34′ to flow through the first passage30′ and/or the second passage32′. It is understood, however, that in other embodiments the valve97′ is open, permitting the third fluid from the third fluid source95′ to circulate through the conduit96′ to the heater core28′, and thereby further heat the conditioned air flowing through the second passage32′ to a desired temperature.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10′ is operating in another alternative heating mode, the valve76′ is closed to militate against the circulation of the first fluid from the first fluid source70′ through the conduit72′ to the evaporator core24′. Additionally, the valve86′ is closed to militate against the circulation of the second fluid from the second fluid source80′ through the conduit82′ to the internal thermal energy exchanger78′, the valve93′ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88′ through the conduit92′ to the external thermal energy exchanger89′, the valve97′ is closed to militate against the circulation of the third fluid from the third fluid source95′ through the conduit96′ to the heater core28′, and the valve110is closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89′ through the bypass conduit110. However, the fourth fluid from the fourth fluid source102circulates through the conduit90′, through the inoperative external thermal energy exchanger89′, and through the conduit104to the internal thermal energy exchanger78′. Accordingly, the air from the inlet section16′ flows through the evaporator core24′ where a temperature of the air is relatively unaffected. The unconditioned air then exits the evaporator core24′ and flows to the internal thermal energy exchanger78′. As the air flows through the internal thermal energy exchanger78′, the air is heated to a desired temperature by a transfer of thermal energy from the fourth fluid from the fourth fluid source102to the air flowing through the internal thermal energy exchanger78′. The conditioned air then exits the internal thermal energy exchanger78′ and is selectively permitted by the blend door34′ to flow through the first passage30′ and/or the second passage32′. It is understood, however, that in other embodiments the valve93is open permitting the circulation of the exhaust gas from the exhaust gas system88′ through the conduit92′ to the external thermal energy exchanger89′ to transfer thermal energy to the fourth fluid from the fourth fluid source102and/or the valve97′ is open, permitting the third fluid from the third fluid source95′ to circulate through the conduit96′ to the heater core28′, and thereby further heat the conditioned air flowing through the second passage32′ to a desired temperature.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10′ is operating in another alternative heating mode or a hot thermal energy charge mode, the valve76′ is closed to militate against the circulation of the first fluid from the first fluid source70′ through the conduit72′ to the evaporator core24′. Similarly, the valve86′ is closed to militate against the circulation of the second fluid from the second fluid source80′ through the conduit82′ to the internal thermal energy exchanger78′, the valve110is closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89′ through the bypass conduit110, and the valve97′ is closed to militate against the circulation of the third fluid from the third fluid source95′ through the conduit96′ to the heater core28′. However, the fourth fluid from the fourth fluid source102circulates through the conduit90′, through the external thermal energy exchanger89′, and through the conduit104to the internal thermal energy exchanger78′. The exhaust gas from the exhaust gas system88′ circulates through the conduit92′ to the external thermal energy exchanger89′. In the fourth fluid source102, the fourth fluid, which has been heated by the exhaust gas, transfers thermal energy to heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102. Accordingly, the air from the inlet section16′ flows through the evaporator core24′ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24′ to the internal thermal energy exchanger78′. As the air flows through the internal thermal energy exchanger78′, the air is heated to a desired temperature by a transfer of thermal energy from the fourth fluid to the air flowing through the internal thermal energy exchanger78′. The conditioned air then exits the internal thermal energy exchanger78′ and is selectively permitted by the blend door34′ to flow through the first passage30′ and/or the second passage32′. It is understood, however, that in other embodiments the valve97′ is open, permitting the third fluid from the third fluid source95′ to circulate through the conduit96′ to the heater core28′, and thereby further heat the conditioned air flowing through the second passage32′ to a desired temperature

When the fuel-powered engine of the vehicle is not in operation and the HVAC system10′ is operating in an engine-off heating mode, the first fluid from the first fluid source70′ does not circulate through the conduit72′ to the evaporator core24′. Similarly, the valve86′ is closed to militate against the circulation of the second fluid from the second fluid source80′ through the conduit82′ to the internal thermal energy exchanger78′ and the valve110is closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89′ through the bypass conduit108to the internal thermal energy exchanger78′. Additionally, the exhaust gas from the exhaust gas system88′ does not circulate through the conduit92′ to the external thermal energy exchanger89′ and the third fluid from the third fluid source95′ does not circulate through the conduit96′ to the heater core28′. However, the fourth fluid from the fourth fluid source102circulates through the conduit90′, through the inoperative external thermal energy exchanger89′, and through the conduit104to the internal thermal energy exchanger78′. Accordingly, the air from the inlet section16′ flows through the evaporator core24′ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24′ to the internal thermal energy exchanger78′. As the air flows through the internal thermal energy exchanger78′, the air is heated to a desired temperature by a transfer of thermal energy from the fourth fluid from the fourth fluid source102to the air flowing through the internal thermal energy exchanger78′. The conditioned air then exits the thermal energy exchanger78′ and is selectively permitted by the blend door34′ to flow through the first passage30′ and/or the second passage32′.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10′ is operating in a recirculation heating mode or an alternative hot thermal energy charge mode, the valve76′ is closed to militate against the circulation of the first fluid from the first fluid source70′ through the conduit72′ to the evaporator core24′. Similarly, the valve86′ is closed to militate against the circulation of the second fluid from the second fluid source80′ through the conduit82′ to the internal thermal energy exchanger78′. Additionally, the valves91′,106,110are closed to militate against the circulation of the fourth fluid to the internal thermal energy exchanger78′, the valve93′ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88′ through the conduit92′ to the external thermal energy exchanger89′, and the valve97′ is closed to militate against the circulation of the third fluid from the third fluid source95′ through the conduit96′ to the heater core28′. Accordingly, a re-circulated air from a passenger compartment of the vehicle flows through the inlet section16′, through the evaporator core24′, and into the internal thermal energy exchanger78′ where a temperature of the air is relatively unaffected. The re-circulated air then exits the internal thermal energy exchanger78′ and is selectively permitted by the blend door34to flow through the first passage30′ and/or the second passage32′. It is understood, however, that in other embodiments the valves91′,110,93′ are open permitting the fourth fluid from the external thermal energy exchanger89′ heated by the exhaust gas to circulate through the conduits91′,108to the internal thermal energy exchanger78′, the valves91′,106are open permitting the fourth fluid from the fourth fluid source102heated by the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102to circulate through the conduits91′,104to the internal thermal energy exchanger78′, the valves91′,106,93′ are open permitting the fourth fluid from the fourth fluid source102heated by the exhaust gas and the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102to circulate through the conduits91′,104to the internal thermal energy exchanger78′, and/or the valve97′ is open permitting the third fluid from the third fluid source95′ to circulate through the conduit96′ to the heater core28′, and thereby heat the re-circulated air flowing through the first passage30′ and/or the second passage32′. It is further understood that the valves91′,106are open permitting the fourth fluid to absorb thermal energy from air flowing through the internal thermal energy exchanger78′, and thereby heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102.

FIG. 4shows an alternative embodiment of the HVAC systems10,10′ illustrated inFIGS. 1 and 3. Structure similar to that illustrated inFIGS. 1-3includes the same reference numeral and a double prime (″) symbol for clarity.

InFIG. 4, the HVAC system10″ includes a control module12″ to control at least a temperature of the passenger compartment. The module12″ illustrated includes a hollow main housing14″ with an air flow conduit15″ formed therein. The housing14″ includes an inlet section16″, a mixing and conditioning section18″, and an outlet and distribution section (not shown). In the embodiment shown, an air inlet22″ is formed in the inlet section16″. The air inlet22″ is in fluid communication with a supply of air (not shown). The supply of air can be provided from outside of the vehicle, recirculated from the passenger compartment of the vehicle, or a mixture of the two, for example. The inlet section16″ is adapted to receive a blower wheel (not shown) therein to cause air to flow through the air inlet22″. A filter (not shown) can be provided upstream, in, or downstream of the inlet section16″ in respect of a direction of flow through the module12″ if desired.

The mixing and conditioning section18″ of the housing14″ is configured to receive an evaporator core24″ and a heater core28″ therein. As shown, at least a portion of the mixing and conditioning section18″ is divided into a first passage30″ and a second passage32″. In particular embodiments, the evaporator core24″ is disposed upstream of a selectively positionable blend door34″ in respect of the direction of flow through the module12″ and the heater core28″ is disposed in the second passage32″ downstream of the blend door34″ in respect of the direction of flow through the module12″. A filter (not shown) can also be provided upstream of the evaporator core24″ in respect of the direction of flow through the module12″, if desired.

The evaporator core24″ of the present invention is a multi-layer louvered-fin thermal energy exchanger. In a non-limiting example, the evaporator core24″ has a first layer40″, a second layer42″, and a third layer44″ arranged substantially perpendicular to the direction of flow through the module12″. Additional or fewer layers than shown can be employed as desired. The layers40″,42″,44″ are arranged so the second layer42″ is disposed downstream of the first layer40″ and upstream of the third layer44″ in respect of the direction of flow through the module12″. It is understood, however, that the layers40″,42″,44″ can be arranged as desired. The layers40″,42″,44″ can be bonded together by any suitable method as desired such as brazing and welding, for example.

In a particular embodiment, the layers40″,42″ of the evaporator core24″, shown inFIG. 4, are in fluid communication with a first fluid source70″ via a conduit72″. The first fluid source70″ includes a prime mover74″ such as a compressor or a pump, for example, to cause a first fluid to circulate therein. Each of the layers40″,42″ is configured to receive a flow of the first fluid from the first fluid source70″ therein. The first fluid absorbs thermal energy to condition the air flowing through the HVAC module12″ when a fuel-powered engine of the vehicle, and thereby the prime mover74″, is in operation. As a non-limiting example, the first fluid source70″ is a refrigeration circuit, and the first fluid is a refrigerant such as R134a, HFO-1234yf, AC-5, AC-6, and CO2, for example. A valve76″ can be disposed in the conduit72″ to selectively control the flow of the first fluid therethrough.

The HVAC system10″ includes an internal thermal energy exchanger78″ in fluid communication with a second fluid source80″ via a conduit82″. The second fluid source80″ includes a prime mover84″ (e.g. an electrical coolant pump) to cause a second fluid to circulate through the internal thermal energy exchanger78″. As illustrated, the internal thermal energy exchanger78″ is the layer44″ of the evaporator core24″. In other embodiments, the layers40″,44″ of the evaporator core24″ are in fluid communication with the first fluid source70″ and the internal thermal energy exchanger78″ is the layer42″ of the evaporator core24″ in thermal energy exchange relationship with the second fluid source80″. In yet other certain embodiments, only the layer40″ of the evaporator core24″ is in fluid communication with the first fluid source70″ and the internal thermal energy exchanger78″ is the layers42″,44″ of the evaporator core24″ in thermal energy exchange relationship with the second fluid source80″.

The internal thermal energy exchanger78″ is configured to receive a flow of the second fluid from the second fluid source80″ therein. The second fluid absorbs or releases thermal energy to condition the air flowing through the HVAC module12″. A valve86″ can be disposed in the conduit82″ to selectively control the flow of the second fluid therethrough. As a non-limiting example, the second fluid source80″ is a fluid reservoir containing a phase change material (PCM) therein. Those skilled in the art will appreciate that the phase change material can be any suitable material that melts and solidifies at predetermined temperatures and is capable of storing and releasing thermal energy such as organic, inorganic, eutectic and ionic liquids (e.g. a paraffin, a paraffin wax, an alcohol, water, a polygycol, a glycol), and the like, or any combination thereof, for example. The phase change material can also be impregnated with a thermally conductive material such as graphite powder, for example, to further enhance the transfer of thermal energy. As another non-limiting example, the second fluid source80″ is a fluid reservoir containing a coolant therein. As another non-limiting example, the second fluid source80″ is a fluid reservoir containing a phase change material coolant such as CryoSolplus, for example, therein. As yet another non-limiting example, the second fluid source80″ is an external thermal energy exchanger (e.g. a shell and tube heat exchanger, a chiller, etc.) which includes a phase change material disposed therein and/or is in fluid communication with at least one other vehicle system.

In certain embodiments, the internal thermal energy exchanger78″ is in thermal energy exchange relationship with an exhaust gas system88″ of the vehicle via an external thermal energy exchanger89″. Those skilled in the art will appreciate that the external thermal energy exchanger89″ can be any suitable thermal energy exchanger such as an exhaust gas recirculation (EGR) thermal energy exchanger, for example. As illustrated, the external thermal energy exchanger89″ is in fluid communication with the internal thermal energy exchanger78″ and configured to receive, through a conduit90″, a flow of the working fluid therein. A valve91″ can be disposed in the conduit90″ to selectively control the flow of the working fluid therethrough. The external thermal energy exchanger89″ is also in fluid communication with the exhaust gas system88″ and configured to receive, through a conduit92″, a flow of an exhaust gas therein. As shown, the flow of the exhaust gas through the external thermal energy exchanger89″ is counter to the flow of the working fluid therethrough. It is understood that the flow of the exhaust gas through the external thermal energy exchanger89″ can be in any suitable flow direction in respect of the flow of the working fluid as desired such as a concurrent flow direction and a cross-flow direction, for example. A valve93″ can be disposed in the conduit92″ to selectively control the flow of the exhaust gas therethrough. The external thermal energy exchanger89″ facilitates a transfer of thermal energy from the exhaust gas to heat the working fluid, especially when the fuel-powered engine of the vehicle is in operation. The exhaust gas is typically at a temperature in a range of about 400° C. to about 1000° C. As such, the working fluid is heated very rapidly and may heat the air flowing through the air flow conduit15″ before the fuel-powered engine reaches a normal operating temperature. Accordingly, a size and capacity of the heater core28″ may be decreased in respect of heater cores of the prior art, which may facilitate a decrease in air side pressure drop during heating modes of the HVAC system10″, as well as an increase in available package space within the control module12″.

As shown, the heater core28″ is in fluid communication with a third fluid source95″ via a conduit96″. The heater core28″ is configured to receive a flow of a third fluid from the third fluid source95″ therein. The third fluid source95″ can be any conventional source of heated fluid such as the fuel-powered engine or a battery system of the vehicle, for example, and the third fluid can be any conventional fluid such as a phase change material, a coolant, or a phase change material coolant, for example. A valve97″ can be disposed in the conduit96″ to selectively control the flow of the third fluid therethrough. The heater core28″ is configured to facilitate a release of thermal energy from the third fluid to heat the air flowing therethrough when the fuel-powered engine of the vehicle is in operation.

A fourth fluid source102″ is in fluid communication with the external thermal energy exchanger89″ via the conduit90″. The fourth fluid source102″ is configured to receive a flow of a fourth fluid therein. In certain embodiments, the fourth fluid is the working fluid from the external thermal energy exchanger89″. It is understood that any of the second fluid from the second fluid source80″, the working fluid from the external thermal energy exchanger89″, the third fluid from the third fluid source95″, and the fourth fluid from the fourth fluid source102″ may be the same or different fluid types if desired. As a non-limiting example, the fourth fluid source102″ is a fluid reservoir containing a phase change material (PCM) therein. Those skilled in the art will appreciate that the phase change material can be any suitable material that melts and solidifies at predetermined temperatures and is capable of storing and releasing thermal energy such as organic, inorganic, eutectic and ionic liquids (e.g. a paraffin, a paraffin wax, an alcohol, water, a polygycol, a glycol), and the like, or any combination thereof, for example. The phase change material can also be impregnated with a thermally conductive material such as graphite powder, for example, to further enhance the transfer of thermal energy. As another non-limiting example, the fourth fluid source102″ is a fluid reservoir containing a coolant therein. As another non-limiting example, the fourth fluid source102″ is a fluid reservoir containing a phase change material coolant such as CryoSolplus, for example, therein. As yet another non-limiting example, the fourth fluid source102″ is an external thermal energy exchanger (e.g. a shell and tube heat exchanger, a chiller, etc.) which includes a phase change material disposed therein.

As illustrated, the fourth fluid source102″ is in thermal energy exchange relationship with an exhaust gas system204of the vehicle. It is understood that the exhaust gas system204can be separate from or at least a part of the exhaust gas system88″. In certain embodiments, the fourth fluid source102″ is in fluid communication with the exhaust gas system204and configured to receive, through a conduit206, a flow of an exhaust gas therein. A valve208can be disposed in the conduit206to selectively control the flow of the exhaust gas therethrough. As shown, the flow of the exhaust gas through the fourth fluid source102″ is counter to the flow of the fourth fluid therethrough. It is understood that the flow of the exhaust gas through the fourth fluid source102″ can be in any suitable flow direction in respect of the flow of the working fluid as desired such as a concurrent flow direction and a cross-flow direction, for example. The fourth fluid source102″ facilitates a transfer of thermal energy from the exhaust gas to heat the fourth fluid, especially when the fuel-powered engine of the vehicle is in operation. The exhaust gas is typically at a temperature in a range of about 400° C. to about 1000° C. As such, the fourth fluid is heated very rapidly and may heat the air flowing through the air flow conduit15″ before the fuel-powered engine reaches a normal operating temperature. Accordingly, a size and capacity of the heater core28″ may be decreased in respect of heater cores of the prior art, which may facilitate a decrease in air side pressure drop during heating modes of the HVAC system10″, as well as an increase in available package space within the control module12″.

In operation, the HVAC system10″ conditions air by heating or cooling the air, and providing the conditioned air to the passenger compartment of the vehicle. Air from the supply of air is received in the inlet section16″ of the housing14″ in the air inlet22″ and flows through the housing14″ of the module12″.

In each operating mode of the HVAC system10″, the blend door34″ may be positioned in one of a first position permitting air from the evaporator core24″ and the internal thermal energy exchange78″ to only flow into the first passage30″, a second position permitting the air from the evaporator core24″ and the internal thermal energy exchanger78″ to only flow into the second passage32″, and an intermediate position permitting the air from the evaporator core24″ and the internal thermal energy exchanger78″ to flow through both the first passage30″ and the second passage32″ and through the heater core28″

When the fuel-powered engine of the vehicle is in operation and the HVAC system10″ is operating in either a cooling mode or a cold thermal energy charge mode, the first fluid from the first fluid source70″ circulates through the conduit72″ to the evaporator core24″. Additionally, the second fluid from the second fluid source80″ circulates through the conduit82″ to the internal thermal energy exchanger78″. However, the valve91″ is closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89″ and the fourth fluid source102″ through the conduit90″ to the internal thermal energy exchanger78″, the valve93″ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88″ through the conduit92″ to the external thermal energy exchanger89″, the valve208is closed to militate against the circulation of the exhaust gas from the exhaust gas system204through the conduit206to the fourth fluid source102″, and the valve97″ is closed to militate against the circulation of the third fluid from the third fluid source95″ through the conduit96″ to the heater core28″. Accordingly, the air from the inlet section16″ flows into the evaporator core24″ where the air is cooled to a desired temperature by a transfer of thermal energy from the air to the first fluid from the first fluid source70″. The conditioned air then flows from the evaporator core24″ to the internal thermal energy exchanger78″. As the conditioned air flows through the internal thermal energy exchanger78″, the conditioned air absorbs thermal energy from the second fluid. The transfer of thermal energy from the second fluid to the conditioned air cools the second fluid. The second fluid then flows to the second fluid source80″ and absorbs thermal energy to cool or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source80″. The conditioned air then exits the internal thermal energy exchanger78″ and is selectively permitted by the blend door34″ to flow through the first passage30″ and/or the second passage32″. It is understood, however, that in other embodiments the valve97″ is open, permitting the third fluid from the third fluid source95″ to circulate through the conduit96″ to the heater core28″, and thereby demist the conditioned air flowing through the second passage32″.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10″ is operating in an alternative cooling mode, the first fluid from the first fluid source70″ circulates through the conduit72″ to the evaporator core24″. However, the valve86″ is closed to militate against the circulation of the second fluid from the second fluid source80″ through the conduit82″ to the internal thermal energy exchanger78″. Additionally, the valve91″ is closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89″ and the fourth fluid source102″ through the conduit90″ to the internal thermal energy exchanger78″, the valve93″ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88″ through the conduit92″ to the external thermal energy exchanger89″, the valve208is closed to militate against the circulation of the exhaust gas from the exhaust gas system204through the conduit206to the fourth fluid source102″, and the valve97″ is closed to militate against the circulation of the third fluid from the third fluid source95″ through the conduit96″ to the heater core28″. Accordingly, the air from the inlet section16″ flows into the evaporator core24″ where the air is cooled to a desired temperature by a transfer of thermal energy from the air to the first fluid from the first fluid source70″. The conditioned air then flows from the evaporator core24″ to the internal thermal energy exchanger78″. As the conditioned air flows through the internal thermal energy exchanger78″, the temperature of the conditioned air is relatively unaffected. The conditioned air then exits the internal thermal energy exchanger78″ and is selectively permitted by the blend door34″ to flow through the first passage30″ and/or the second passage32″. It is understood, however, that in other embodiments the valve97″ is open, permitting the third fluid from the third fluid source95″ to circulate through the conduit96″ to the heater core28″, and thereby demist the conditioned air flowing through the second passage32″.

When the fuel-powered engine of the vehicle is not in operation and the HVAC system10″ is operating in an engine-off cooling mode, the first fluid from the first fluid source70″ does not circulate through the conduit72″ to the evaporator core24″. Additionally, the valve91″ is closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89″ and the fourth fluid source102″ through the conduit90″ to the internal thermal energy exchanger78″, the exhaust gas from the exhaust gas system88″ does not circulate through the conduit92″ to the external thermal energy exchanger89″, the exhaust gas from the exhaust gas system204does not circulate through the conduit206to the fourth fluid source102″, and the third fluid from the third fluid source95″ does not circulate through the conduit96″ to the heater core28″. However, the second fluid from the second fluid source80″ circulates through the conduit82″ to the internal thermal energy exchanger78″. Accordingly, the air from the inlet section16″ flows through the evaporator core24″ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24″ to the internal thermal energy exchanger78″. As the air flows through the internal thermal energy exchanger78″, the air is cooled to a desired temperature by a transfer of thermal energy from the air to the second fluid from the second fluid source80″. The conditioned air then exits the thermal energy exchanger78″ and is selectively permitted by the blend door34″ to flow through the first passage30″ and/or the second passage32″.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10″ is operating in a heating mode, the valve76″ is closed to militate against the circulation of the first fluid from the first fluid source70″ through the conduit72″ to the evaporator core24″. Similarly, the valve86″ is closed to militate against the circulation of the second fluid from the second fluid source80″ through the conduit82″ to the internal thermal energy exchanger78″. Additionally, the valve91″ is closed to militate against the circulation of the fourth fluid from the external thermal energy exchanger89″ and the fourth fluid source102″ through the conduit90″ to the internal thermal energy exchanger78″, the valve93″ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88″ through the conduit92″ to the external thermal energy exchanger89″, and the valve208is closed to militate against the circulation of the exhaust gas from the exhaust gas system204through the conduit206to the fourth fluid source102″. However, the third fluid from the third fluid source95″ circulates through the conduit96″ to the heater core28″. Accordingly, the air from the inlet section16″ flows through the evaporator core24″ and the internal thermal energy exchanger78″ where a temperature of the air is relatively unaffected. The unconditioned air then exits the evaporator core24″ and the internal thermal energy exchanger78″ and is selectively permitted by the blend door34″ to flow through the first passage30″ and/or the second passage32″ through the heater core28″ to be heated to a desired temperature.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10″ is operating in an alternative heating mode, the valve76″ is closed to militate against the circulation of the first fluid from the first fluid source70″ through the conduit72″ to the evaporator core24″. Similarly, the valve86″ is closed to militate against the circulation of the second fluid from the second fluid source80″ through the conduit82″ to the internal thermal energy exchanger78″, the valve93″ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88″ through the conduit92″ to the external thermal energy exchanger89″, the valve208is closed to militate against the circulation of the exhaust gas from the exhaust gas system204through the conduit206to the fourth fluid source102″, and the valve97″ is closed to militate against the circulation of the third fluid from the third fluid source95″ through the conduit96″ to the heater core28″. However, the fourth fluid from the fourth fluid source102″ circulates through the conduit90″ and the inoperative external thermal energy exchanger89″ to the internal thermal energy exchanger78″. Accordingly, the air from the inlet section16″ flows through the evaporator core24″ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24″ to the internal thermal energy exchanger78″. As the air flows through the internal thermal energy exchanger78″, the air is heated to a desired temperature by a transfer of thermal energy from the fourth fluid from the fourth fluid source102″ to the air flowing through the internal thermal energy exchanger78″. In the fourth fluid source102″, the fourth fluid absorbs thermal energy from the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102″ to heat the fourth fluid. The conditioned air then exits the internal thermal energy exchanger78″ and is selectively permitted by the blend door34″ to flow through the first passage30″ and/or the second passage32″. It is understood, however, that in other embodiments the valve93″ is open permitting the circulation of the exhaust gas from the exhaust gas system88″ through the conduit92″ to the external thermal energy exchanger89″ to transfer thermal energy to the fourth fluid from the fourth fluid source102″ and/or the valve208is open permitting the circulation of the exhaust gas from the exhaust gas system204through the conduit206to the fourth fluid source102″ to transfer thermal energy to the fourth fluid from the fourth fluid source102″. IT is further understood that in other embodiments the valve97″ is open, permitting the third fluid from the third fluid source95″ to circulate through the conduit96″ to the heater core28″, and thereby further heat the conditioned air flowing through the second passage32″ to a desired temperature.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10″ is operating in another alternative heating mode or a hot thermal energy charge mode, the valve76″ is closed to militate against the circulation of the first fluid from the first fluid source70″ through the conduit72″ to the evaporator core24″. Similarly, the valve86″ is closed to militate against the circulation of the second fluid from the second fluid source80″ through the conduit82″ to the internal thermal energy exchanger78″ and the valve97″ is closed to militate against the circulation of the third fluid from the third fluid source95″ through the conduit96″ to the heater core28″. However, the fourth fluid from the fourth fluid source102″ circulates through the conduit90″ and the external thermal energy exchanger89″, and through the fourth fluid source102″ to the internal thermal energy exchanger78″. At least one of the exhaust gas from the exhaust gas system88″ circulates through the conduit92″ to the external thermal energy exchanger89″ and the exhaust gas from the exhaust gas system204circulates through the conduit206to the fourth fluid source102″ to heat the fourth fluid. In the fourth fluid source102″, the fourth fluid, which has been heated by the exhaust gas from at least one of the exhaust gas systems88″,204, transfers thermal energy to heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102″. Accordingly, the air from the inlet section16″ flows through the evaporator core24″ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24″ to the internal thermal energy exchanger78″. As the air flows through the internal thermal energy exchanger78″, the air is heated to a desired temperature by a transfer of thermal energy from the fourth fluid to the air flowing through the internal thermal energy exchanger78″. The conditioned air then exits the internal thermal energy exchanger78″ and is selectively permitted by the blend door34″ to flow through the first passage30″ and/or the second passage32″. It is understood, however, that in other embodiments the valve97″ is open, permitting the third fluid from the third fluid source95″ to circulate through the conduit96″ to the heater core28″, and thereby further heat the conditioned air flowing through the second passage32″ to a desired temperature

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10″ is operating in an alternative hot thermal energy charge mode, the valve76″ is closed to militate against the circulation of the first fluid from the first fluid source70″ through the conduit72″ to the evaporator core24″. Similarly, the valve86″ is closed to militate against the circulation of the second fluid from the second fluid source80″ through the conduit82″ to the internal thermal energy exchanger78″, the valve91″ is closed to militate against the circulation of the fourth fluid from the fourth fluid source102″ through the conduit90″ to the internal thermal energy exchanger78″, and the valve97″ is closed to militate against the circulation of the third fluid from the third fluid source95″ through the conduit96″ to the heater core28″. Additionally, the valve93″ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88″ to the external thermal energy exchanger89″. However, the exhaust gas from the exhaust gas system204circulates through the conduit206to the fourth fluid source102″ to heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102″. Accordingly, the air from the inlet section16″ flows through the evaporator core24″ and the internal thermal energy exchanger78″ where a temperature of the air is relatively unaffected. The unconditioned air then exits the internal thermal energy exchanger78″ and is selectively permitted by the blend door34″ to flow through the first passage30″ and/or the second passage32″. It is understood, however, that in other embodiments the valve97″ is open, permitting the third fluid from the third fluid source95″ to circulate through the conduit96″ to the heater core28″, and thereby heat the unconditioned air flowing through the second passage32″ to a desired temperature.

When the fuel-powered engine of the vehicle is not in operation and the HVAC system10″ is operating in an engine-off heating mode, the first fluid from the first fluid source70″ does not circulate through the conduit72″ to the evaporator core24″. Similarly, the valve86″ is closed to militate against the circulation of the second fluid from the second fluid source80″ through the conduit82″ to the internal thermal energy exchanger78″. Additionally, the exhaust gas from the exhaust gas system88″ does not circulate through the conduit92″ to the external thermal energy exchanger89″, the exhaust gas from the exhaust gas system204does not circulate through the conduit206to the fourth fluid source102″, and the third fluid from the third fluid source95″ does not circulate through the conduit96″ to the heater core28″. However, the fourth fluid from the fourth fluid source102″ circulates through the conduit90″ and the inoperative external thermal energy exchanger89″, and through the fourth fluid source102″ to the internal thermal energy exchanger78″. In the fourth fluid source102″, the fourth fluid is heated by the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102″. Accordingly, the air from the inlet section16″ flows through the evaporator core24″ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24″ to the internal thermal energy exchanger78″. As the air flows through the internal thermal energy exchanger78″, the air is heated to a desired temperature by a transfer of thermal energy from the fourth fluid from the fourth fluid source102″ to the air flowing through the internal thermal energy exchanger78″. The conditioned air then exits the thermal energy exchanger78″ and is selectively permitted by the blend door34″ to flow through the first passage30″ and/or the second passage32″.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10″ is operating in a recirculation heating mode or another alternative hot thermal energy charge mode, the valve76″ is closed to militate against the circulation of the first fluid from the first fluid source70″ through the conduit72″ to the evaporator core24″. Similarly, the valve86″ is closed to militate against the circulation of the second fluid from the second fluid source80″ through the conduit82″ to the internal thermal energy exchanger78″. Additionally, the valve91″ is closed to militate against the circulation of the fourth fluid to the internal thermal energy exchanger78″, the valve93″ is closed to militate against the circulation of the exhaust gas from the exhaust gas system88″ through the conduit92″ to the external thermal energy exchanger89″, the valve208is closed to militate against the circulation of the exhaust gas from the exhaust gas system204through the conduit206to the fourth fluid source102″, and the valve97″ is closed to militate against the circulation of the third fluid from the third fluid source95″ through the conduit96″ to the heater core28″. Accordingly, a re-circulated air from a passenger compartment of the vehicle flows through the inlet section16″, through the evaporator core24″, and into the internal thermal energy exchanger78″ where a temperature of the air is relatively unaffected. The re-circulated air then exits the internal thermal energy exchanger78″ and is selectively permitted by the blend door34″ to flow through the first passage30″ and/or the second passage32″. It is understood, however, that in other embodiments the valve91″ is open permitting the fourth fluid heated by at least one of the exhaust gas from the exhaust gas system88″, the exhaust gas from the exhaust gas system204, and the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102″ to circulate through the conduit90″ to the internal thermal energy exchanger78″ and/or the valve97″ is open permitting the third fluid from the third fluid source95″ to circulate through the conduit96″ to the heater core28″, and thereby heat the re-circulated air flowing through the first passage30″ and/or the second passage32″. It is further understood that the valve91″ is open permitting the fourth fluid to absorb thermal energy from air flowing through the internal thermal energy exchanger78″, and thereby heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the fourth fluid source102″.

FIG. 5shows an alternative embodiment of the HVAC systems10,10′,10″ illustrated in FIGS.1and3-4. Structure similar to that illustrated inFIGS. 1-4includes the same reference numeral and a triple prime (′″) symbol for clarity.

InFIG. 5, the HVAC system10′″ includes a control module12′″ to control at least a temperature of the passenger compartment. The module12′″ illustrated includes a hollow main housing14′″ with an air flow conduit15′″ formed therein. The housing14′″ includes an inlet section16′″, a mixing and conditioning section18′″, and an outlet and distribution section (not shown). In the embodiment shown, an air inlet22′″ is formed in the inlet section16′″. The air inlet22′″ is in fluid communication with a supply of air (not shown). The supply of air can be provided from outside of the vehicle, recirculated from the passenger compartment of the vehicle, or a mixture of the two, for example. The inlet section16′″ is adapted to receive a blower wheel (not shown) therein to cause air to flow through the air inlet22′″. A filter (not shown) can be provided upstream, in, or downstream of the inlet section16′″ in respect of a direction of flow through the module12′″ if desired.

The mixing and conditioning section18′″ of the housing14′″ is configured to receive an evaporator core24′″ and a heater core28′″ therein. As shown, at least a portion of the mixing and conditioning section18′″ is divided into a first passage30′″ and a second passage32′″. In particular embodiments, the evaporator core24′″ is disposed upstream of a selectively positionable blend door34′″ in respect of the direction of flow through the module12′″ and the heater core28′″ is disposed in the second passage32′″ downstream of the blend door34′″ in respect of the direction of flow through the module12′″. A filter (not shown) can also be provided upstream of the evaporator core24′″ in respect of the direction of flow through the module12′″, if desired.

The evaporator core24′″ of the present invention is a multi-layer louvered-fin thermal energy exchanger. In a non-limiting example, the evaporator core24″ has a first layer40′″, a second layer42′″, and a third layer44′″ arranged substantially perpendicular to the direction of flow through the module12′″. Additional or fewer layers than shown can be employed as desired. The layers40′″,42′″,44′″ are arranged so the second layer42′″ is disposed downstream of the first layer40′″ and upstream of the third layer44′″ in respect of the direction of flow through the module12′″. It is understood, however, that the layers40′″,42′″,44′″ can be arranged as desired. The layers40′″,42′″,44′″ can be bonded together by any suitable method as desired such as brazing and welding, for example.

In a particular embodiment, the layers40′″,42′″ of the evaporator core24′″, shown inFIG. 5, are in fluid communication with a first fluid source70′″ via a conduit72′″. The first fluid source70′″ includes a prime mover74′″ such as a compressor or a pump, for example, to cause a first fluid to circulate therein. Each of the layers40′″,42′″ is configured to receive a flow of the first fluid from the first fluid source70′″ therein. The first fluid absorbs thermal energy to condition the air flowing through the HVAC module12′″ when a fuel-powered engine of the vehicle, and thereby the prime mover74′″, is in operation. As a non-limiting example, the first fluid source70′″ is a refrigeration circuit, and thefirst fluid is a refrigerant such as R134a, HFO-1234yf, AC-5, AC-6, and CO2, for example. A valve76′″ can be disposed in the conduit72′″ to selectively control the flow of the first fluid therethrough.

The HVAC system10′″ includes an internal thermal energy exchanger78′″ in fluid communication with a second fluid source302via a conduit303. The second fluid source302includes a prime mover304(e.g. an electrical coolant pump) to cause a second fluid to circulate through the internal thermal energy exchanger78′″. As illustrated, the internal thermal energy exchanger78′″ is the layer44′″ of the evaporator core24′″. In other embodiments, the layers40′″,44′″ of the evaporator core24′″ are in fluid communication with the first fluid source70′″ and the internal thermal energy exchanger78′″ is the layer42′″ of the evaporator core24′″ in thermal energy exchange relationship with the second fluid source302. In yet other certain embodiments, only the layer40′″ of the evaporator core24′″ is in fluid communication with the first fluid source70′″ and the internal thermal energy exchanger78′″ is the layers42′″,44′″ of the evaporator core24′″ in thermal energy exchange relationship with the second fluid source302.

The internal thermal energy exchanger78′″ is configured to receive a flow of the second fluid from the second fluid source302therein. The second fluid absorbs or releases thermal energy to condition the air flowing through the HVAC module12′″. A valve306can be disposed in the conduit303to selectively control the flow of the second fluid therethrough. As a non-limiting example, the second fluid source302is a fluid reservoir containing a phase change material (PCM) therein. Those skilled in the art will appreciate that the phase change material can be any suitable material that melts and solidifies at predetermined temperatures and is capable of storing and releasing thermal energy such as organic, inorganic, eutectic and ionic liquids (e.g. a paraffin, a paraffin wax, an alcohol, water, a polygycol, a glycol), and the like, or any combination thereof, for example. The phase change material can also be impregnated with a thermally conductive material such as graphite powder, for example, to further enhance the transfer of thermal energy. As another non-limiting example, the second fluid source302is a fluid reservoir containing a coolant therein. As another non-limiting example, the second fluid source302is a fluid reservoir containing a phase change material coolant such as CryoSolplus, for example, therein. As yet another non-limiting example, the second fluid source302is an external thermal energy exchanger (e.g. a shell and tube heat exchanger, a chiller, etc.) which includes a phase change material disposed therein and/or is in fluid communication with at least one other vehicle system.

As illustrated, the second fluid source302is in thermal energy exchange relationship with an exhaust gas system314of the vehicle. In certain embodiments, the second fluid source302is in fluid communication with the exhaust gas system314and configured to receive, through a conduit316, a flow of an exhaust gas therein. A valve318can be disposed in the conduit316to selectively control the flow of the exhaust gas therethrough. As shown, the flow of the exhaust gas through the second fluid source302is counter to the flow of the second fluid therethrough. It is understood that the flow of the exhaust gas through the second fluid source302can be in any suitable flow direction in respect of the flow of the working fluid as desired such as a concurrent flow direction and a cross-flow direction, for example. The second fluid source302facilitates a transfer of thermal energy from the exhaust gas to heat the second fluid, especially when the fuel-powered engine of the vehicle is in operation. The exhaust gas is typically at a temperature in a range of about 400° C. to about 1000° C. As such, the second fluid is heated very rapidly and may heat the air flowing through the air flow conduit15′″ before the fuel-powered engine reaches a normal operating temperature. Accordingly, a size and capacity of the heater core28′″ may be decreased in respect of heater cores of the prior art, which may facilitate a decrease in air side pressure drop during heating modes of the HVAC system10′″, as well as an increase in available package space within the control module12′″.

As shown, the heater core28′″ is in fluid communication with a third fluid source95′″ via a conduit96′″. The heater core28′″ is configured to receive a flow of a third fluid from the third fluid source95′″ therein. The third fluid source95′″ can be any conventional source of heated fluid such as the fuel-powered engine or a battery system of the vehicle, for example, and the third fluid can be any conventional fluid such as a phase change material, a coolant, or a phase change material coolant, for example. A valve97′″ can be disposed in the conduit96′″ to selectively control the flow of the third fluid therethrough. The heater core28′″ is configured to facilitate a release of thermal energy from the third fluid to heat the air flowing therethrough when the fuel-powered engine of the vehicle is in operation.

In certain embodiments, the heater core28′″ and the third fluid source95′″ are also in fluid communication with the internal thermal energy exchanger78′″ via a conduit320. The internal thermal energy exchanger78′″ is configured to facilitate a release of thermal energy from the third fluid to heat the air flowing therethrough. Accordingly, a size and capacity of the heater core28′″ may be further decreased in respect of heater cores of the prior art, which may facilitate a further decrease in air side pressure drop during heating modes of the HVAC system10′″, as well as a further increase in available package space within the control module12′″. A valve322can be disposed in the conduit320to selectively militate against the flow of the third fluid therethrough. As a non-limiting example, the second fluid from the second fluid source302and the third fluid from the third fluid source95′″ are the same fluid types. It is understood, however, that the second fluid from the second fluid source302and the third fluid from the third fluid source95′″ may be different fluid types if desired.

FIG. 6shows another alternative embodiment of the HVAC systems10,10′,10″,10′″ illustrated in FIGS.1and3-5. Structure similar to that illustrated inFIGS. 1-5includes the same reference numeral and a quadruple prime (″″) symbol for clarity. InFIG. 6, the HVAC system10″″ is substantially similar to the HVAC systems10,10′,10″,10′″ except the second fluid source302″″ is a thermal energy exchanger (e.g. a gas-to-liquid thermal energy exchanger) in thermal energy exchange relationship with the exhaust gas system314′″.

It is understood that the operation of the HVAC system10″″ is substantially similar to the operation of the HVAC system10″. For simplicity, only the operation of the HVAC system10′″ is described hereinafter.

In operation, the HVAC system10′″ conditions air by heating or cooling the air, and providing the conditioned air to the passenger compartment of the vehicle. Air from the supply of air is received in the inlet section16′″ of the housing14′″ in the air inlet22′″ and flows through the housing14′″ of the module12′″.

In each operating mode of the HVAC system10′″, the blend door34′″ may be positioned in one of a first position permitting air from the evaporator core24′″ and the internal thermal energy exchange78′″ to only flow into the first passage30′″, a second position permitting the air from the evaporator core24′″ and the internal thermal energy exchanger78′″ to only flow into the second passage32′″, and an intermediate position permitting the air from the evaporator core24′″ and the internal thermal energy exchanger78′″ to flow through both the first passage30′″ and the second passage32′″ and through the heater core28′″.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10′″ is operating in either a cooling mode or a cold thermal energy charge mode, the first fluid from the first fluid source70′″ circulates through the conduit72′″ to the evaporator core24′″. Additionally, the second fluid from the second fluid source302circulates through the conduit303to the internal thermal energy exchanger78′″. However, the valve318is closed to militate against the circulation of the exhaust gas from the exhaust gas system314through the conduit316to the second fluid source302and the valves97′″,322are closed to militate against the circulation of the third fluid from the third fluid source95′″ through the conduit96′″ to the heater core28′″ and through the conduit320to the internal thermal energy exchanger78′″. Accordingly, the air from the inlet section16′″ flows into the evaporator core24′″ where the air is cooled to a desired temperature by a transfer of thermal energy from the air to the first fluid from the first fluid source70′″. The conditioned air then flows from the evaporator core24′″ to the internal thermal energy exchanger78′″. As the conditioned air flows through the internal thermal energy exchanger78′″, the conditioned air absorbs thermal energy from the second fluid. The transfer of thermal energy from the second fluid to the conditioned air cools the second fluid. The second fluid then flows to the second fluid source302and absorbs thermal energy to cool or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source302. The conditioned air then exits the internal thermal energy exchanger78′″ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″. It is understood, however, that in other embodiments the valve97′″ is open, permitting the third fluid from the third fluid source95′″ to circulate through the conduit96′″ to the heater core28′″, and thereby demist the conditioned air flowing through the second passage32′″.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10′″ is operating in an alternative cooling mode, the first fluid from the first fluid source70′″ circulates through the conduit72′″ to the evaporator core24′″. However, the valve306is closed to militate against the circulation of the second fluid from the second fluid source302through the conduit303to the internal thermal energy exchanger78′″. Additionally, the valve318is closed to militate against the circulation of the exhaust gas from the exhaust gas system314through the conduit316to the second fluid source302and the valves97′″,322are closed to militate against the circulation of the third fluid from the third fluid source95′″ through the conduit96′″ to the heater core28′″ and through the conduit320to the internal thermal energy exchanger78′″. Accordingly, the air from the inlet section16′″ flows into the evaporator core24′″ where the air is cooled to a desired temperature by a transfer of thermal energy from the air to the first fluid from the first fluid source70′″. The conditioned air then flows from the evaporator core24′″ to the internal thermal energy exchanger78′″. As the conditioned air flows through the internal thermal energy exchanger78′″, the temperature of the conditioned air is relatively unaffected. The conditioned air then exits the internal thermal energy exchanger78′″ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″. It is understood, however, that in other embodiments the valve97′″ is open, permitting the third fluid from the third fluid source95′″ to circulate through the conduit96′″ to the heater core28′″, and thereby demist the conditioned air flowing through the second passage32′″.

When the fuel-powered engine of the vehicle is not in operation and the HVAC system10′″ is operating in an engine-off cooling mode, the first fluid from the first fluid source70′″ does not circulate through the conduit72′″ to the evaporator core24′″. Additionally, the exhaust gas from the exhaust gas system314does not circulate through the conduit316to the second fluid source302and the third fluid from the third fluid source95′″ does not circulate through the conduit96′″ to the heater core28′″ or through the conduit320to the internal thermal energy exchanger78′″. However, the second fluid from the second fluid source302circulates through the conduit303to the internal thermal energy exchanger78′″. Accordingly, the air from the inlet section16′″ flows through the evaporator core24′″ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24′″ to the internal thermal energy exchanger78′″. As the air flows through the internal thermal energy exchanger78′″, the air is cooled to a desired temperature by a transfer of thermal energy from the air to the second fluid from the second fluid source302. The conditioned air then exits the thermal energy exchanger78′″ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10′″ is operating in a heating mode, the valve76′″ is closed to militate against the circulation of the first fluid from the first fluid source70′″ through the conduit72′″ to the evaporator core24′″. Similarly, the valve306is closed to militate against the circulation of the second fluid from the second fluid source302through the conduit303to the internal thermal energy exchanger78′″. Additionally, the valve318is closed to militate against the circulation of the exhaust gas from the exhaust gas system314through the conduit316to the second fluid source302and the valve322is closed to militate against the circulation of the third fluid from the third fluid source95′″ through the conduit320to the internal thermal energy exchanger78′″. However, the third fluid from the third fluid source95′″ circulates through the conduit96′″ to the heater core28′″. Accordingly, the air from the inlet section16′″ flows through the evaporator core24′″ and the internal thermal energy exchanger78′″ where a temperature of the air is relatively unaffected. The unconditioned air then exits the evaporator core24′″ and the internal thermal energy exchanger78′″ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″ through the heater core28′″ to be heated to a desired temperature.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10′″ is operating in an alternative heating mode, the valve76′″ is closed to militate against the circulation of the first fluid from the first fluid source70′″ through the conduit72′″ to the evaporator core24′″. Similarly, the valve306is closed to militate against the circulation of the second fluid from the second fluid source302through the conduit303to the internal thermal energy exchanger78′″. Additionally, the valve318is closed to militate against the circulation of the exhaust gas from the exhaust gas system314through the conduit316to the second fluid source302. However, the third fluid from the third fluid source95′″ circulates through the respective conduits96′″,320to the heater core28′″ and the internal thermal energy exchanger78′″. Accordingly, the air from the inlet section16′″ flows through the evaporator core24′″ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24′″ to the internal thermal energy exchanger78′″. As the air flows through the internal thermal energy exchanger78′″, the air is heated to a desired temperature by a transfer of thermal energy from the third fluid from the third fluid source95′″ to the air flowing through the internal thermal energy exchanger78′″. The conditioned air then exits the internal thermal energy exchanger78′″ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″ through the heater core28′″ to be further heated to a desired temperature.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10′″ is operating in an alternative heating mode, the valve76′″ is closed to militate against the circulation of the first fluid from the first fluid source70′″ through the conduit72′″ to the evaporator core24′″. Similarly, the valve318is closed to militate against the circulation of the exhaust gas from the exhaust gas system314through the conduit316to the second fluid source302and the valves97′″,322are closed to militate against the circulation of the third fluid from the third fluid source95′″ through the respective conduits96′″,320to the heater core28′″ and the internal thermal energy exchanger78′″. Accordingly, the air from the inlet section16′″ flows through the evaporator core24′″ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24′″ to the internal thermal energy exchanger78′″. As the air flows through the internal thermal energy exchanger78′″, the air is heated to a desired temperature by a transfer of thermal energy from the second fluid from the second fluid source302to the air flowing through the internal thermal energy exchanger78′″. In the second fluid source302, the second fluid absorbs thermal energy from the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source302to heat the second fluid. The conditioned air then exits the internal thermal energy exchanger78′″ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″. It is understood, however, that in other embodiments the valve318is open permitting the circulation of the exhaust gas from the exhaust gas system314through the conduit316to the second fluid source302to transfer thermal energy to the second fluid from the second fluid source302. It is further understood that in other embodiments the valve97′″ is open, permitting the third fluid from the third fluid source95′″ to circulate through the conduit96′″ to the heater core28′″, and thereby further heat the conditioned air flowing through the second passage32′″ to a desired temperature.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10′″ is operating in another alternative heating mode, the valve76′″ is closed to militate against the circulation of the first fluid from the first fluid source70′″ through the conduit72′″ to the evaporator core24′″. Similarly, the valve306is closed to militate against the circulation of the second fluid from the second fluid source302through the conduit303to the internal thermal energy exchanger78′″, the valve318is closed to militate against the circulation of the exhaust gas from the exhaust gas system314through the conduit316to the second fluid source302, and the valve97′″ is closed to militate against the circulation of the third fluid from the third fluid source95′″ through the conduit96′″ to the heater core28′″. However, the third fluid from the third fluid source95′″ circulates through the conduit320to the internal thermal energy exchanger78′″. Accordingly, the air from the inlet section16′″ flows through the evaporator core24′″ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24′″ to the internal thermal energy exchanger78′″. As the air flows through the internal thermal energy exchanger78′″, the air is heated to a desired temperature by a transfer of thermal energy from the third fluid to the air flowing through the internal thermal energy exchanger78′″. The conditioned air then exits the internal thermal energy exchanger78′ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″. It is understood, however, that in other embodiments the valve97′″ is open, permitting the third fluid from the third fluid source95′″ to circulate through the conduit96′″ to the heater core28′″, and thereby further heat the conditioned air flowing through the second passage32′″ to a desired temperature.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10′″ is operating in another alternative heating mode or a hot thermal energy charge mode, the valve76′″ is closed to militate against the circulation of the first fluid from the first fluid source70′″ through the conduit72′″ to the evaporator core24′″. Similarly, the valve318is closed to militate against the circulation of the exhaust gas from the exhaust gas source314through the conduit316to the second fluid source302. However, the second fluid from the second fluid source302circulates through the conduit303to the internal thermal energy exchanger78′″ and the third fluid from the third fluid source95′″ circulates through the respective conduits96′″,320to the heater core28′″ and the internal thermal energy exchanger78′″. The second fluid mixes with the third fluid before, in, or after flowing through the internal thermal energy exchanger78′″. Accordingly, the air from the inlet section16′″ flows through the evaporator core24′″ where a temperature of the air is relatively unaffected. The unconditioned air then flows from the evaporator core24′″ to the internal thermal energy exchanger78′″. As the air flows through the internal thermal energy exchanger78′″, the air is heated to a desired temperature by a transfer of thermal energy from the mixture of the second fluid and the third fluid to the air flowing through the internal thermal energy exchanger78′″. The mixture of the second fluid and the third fluid then flows to the second fluid source302to heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source302. The conditioned air then exits the internal thermal energy exchanger78′″ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″ through the heater core28′″ to be further heated to a desired temperature. It is understood, however, that in other embodiments the valve318is open, permitting the exhaust gas from the exhaust gas system314to circulate through the conduit316to the second fluid source302, and thereby further heat the second fluid.

In other certain embodiments, when the fuel-powered engine of the vehicle is in operation and the HVAC system10′″ is operating in another alternative heating mode or a hot thermal energy charge mode, the valve76′″ is closed to militate against the circulation of the first fluid from the first fluid source70′″ through the conduit72′″ to the evaporator core24′″. Similarly, the valve306is closed to militate against the circulation of the second fluid from the second fluid source302through the conduit303to the internal thermal energy exchanger78′″, the valve322is closed to militate against the circulation of the third fluid from the third fluid source95′″ through the conduit320to the internal thermal energy exchanger78′″, and the valve97′″ is closed to militate against the circulation of the third fluid from the third fluid source95′″ through the conduit96′″ to the heater core28′″. However, the exhaust gas from the exhaust gas system314circulates through the conduit316to the second fluid source302to heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source302. Accordingly, the air from the inlet section16′″ flows through the evaporator core24′″ and the internal thermal energy exchanger78′″ where a temperature of the air is relatively unaffected. The unconditioned air then exits the internal thermal energy exchanger78′″ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″. It is understood, however, that in other embodiments the valve97′″ is open, permitting the third fluid from the third fluid source95′″ to circulate through the conduit96′″ to the heater core28′″, and thereby heat the unconditioned air flowing through the second passage32′″ to a desired temperature.

When the fuel-powered engine of the vehicle is not in operation and the HVAC system10′″ is operating in an engine-off heating mode, the first fluid from the first fluid source70′″ does not circulate through the conduit72′″ to the evaporator core24′″. The exhaust gas from the exhaust gas system314does not circulate through the conduit316to the second fluid source302and the third fluid from the third fluid source95′″ does not circulate through the respective conduit96′″,320to the heater core28′″ and the internal thermal energy exchanger78′″. However, the second fluid from the second fluid source302circulates through the conduit313to the internal thermal energy exchanger78′″. In the second fluid source302, the second fluid is heated by the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source302. Accordingly, the air from the inlet section16′″ flows through the evaporator core24′″ where a temperature of the air is relatively unaffected. The air then flows from the evaporator core24′″ to the internal thermal energy exchanger78′″. As the air flows through the internal thermal energy exchanger78′″, the air is heated to a desired temperature by a transfer of thermal energy from the second fluid from the second fluid source302to the air flowing through the internal thermal energy exchanger78′″. The conditioned air then exits the thermal energy exchanger78′″ and is selectively permitted by the blend door34′″ to flow through the first passage30′″ and/or the second passage32′″.

When the fuel-powered engine of the vehicle is in operation and the HVAC system10′″ is operating in a recirculation heating mode or another alternative hot thermal energy charge mode, the valve76′″ is closed to militate against the circulation of the first fluid from the first fluid source70′″ through the conduit72′″ to the evaporator core24′″. Similarly, the valve306is closed to militate against the circulation of the second fluid from the second fluid source302through the conduit303to the internal thermal energy exchanger78′″. Additionally, the valve318is closed to militate against the circulation of the exhaust gas from the exhaust gas system314through the conduit318to the second fluid source302, and the valves97′″,322are closed to militate against the circulation of the third fluid from the third fluid source95′″ through the respective conduits96′″,320to the heater core28′″ and the internal thermal energy exchanger78′″. Accordingly, a re-circulated air from a passenger compartment of the vehicle flows through the inlet section16′″, through the evaporator core24′″, and into the internal thermal energy exchanger78′″ where a temperature of the air is relatively unaffected. The re-circulated air then exits the internal thermal energy exchanger78′″ and is selectively permitted by the blend door34to flow through the first passage30′″ and/or the second passage32′″. It is understood, however, that in other embodiments the valve306is open permitting the second fluid heated by at least one of the exhaust gas from the exhaust gas system314, and the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source302to circulate through the conduit303to the internal thermal energy exchanger78′″, the valve97′″ is open permitting the third fluid from the third fluid source95′″ to circulate through the conduit96′″ to the heater core28′″, and/or the valve322is open permitting the third fluid from the third fluid source95′″ to circulate through the conduit320to the internal thermal energy exchanger78′″, and thereby heat the re-circulated air flowing through the first passage30′″ and/or the second passage32′″. It is further understood that the valve306is open permitting the second fluid to absorb thermal energy from air flowing through the internal thermal energy exchanger78′″, and thereby heat or charge the phase change material, the coolant, the phase change material coolant, or any combination thereof contained in the second fluid source302.