Patent Publication Number: US-2009229785-A1

Title: Individual HVAC climate control seats

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to thermally conditioning a seat in an automotive vehicle using an HVAC system of the vehicle. 
     2. Description of the Prior Art 
     The thermal comfort of occupants in a vehicle is traditionally provided by the central heating, ventilation and air conditioning (HVAC) assembly of the vehicle controlled by the vehicle occupant. The occupant selects a predetermined air temperature indicating a desired air temperature at which to be thermally conditioned. In response, traditional HVAC assemblies operate in either a warm-up mode and/or a cool-down mode to generate heated and/or cooled air having a temperature approximately equal to the predetermined air temperature. The warmed and/or cooled air can be exhausted into the vehicle cabin, under the seat, and/or behind the seat via one or more air ducts. As a result, the occupant is heated and/or cooled by convection through the surrounding medium in the interior of the vehicle. More recently, vehicle seating assemblies have been disclosed that provide for heating and cooling of the occupant by an independent thermoelectrically energized unit incorporated into a vehicle seat. These units typically consist of one or more thermoelectric modules, heat exchangers and fans that are operated by allowing the fan to blow air over the sides of the seat, resulting in the seat being thermally conditioned. Further, the warmed and/or cooled air can be directed through or over the seat to the occupant&#39;s body surface via seat outlets disposed in the seat assembly. At startup, the air delivered by these thermoelectrically climate controlled seats is initially cold when the HVAC assembly operates in the warm-up. Similarly, the air is initially warm when the HVAC assembly operates in the cool-down mode. As a result, a natural transient thermal response exists that effects the air exhausted from the seat outlets of the seat assembly. 
     The cooling and heating of a occupant in an automotive vehicle can most effectively be obtained by applying the thermal condition directly to the human being. The current automotive air conditioning systems utilize ducts, such as cabin ducts and seat ducts, which lead to vents for delivering warm and/or cool air to the vehicle cabin and seat assembly. The effectiveness in cooling and/or heating occupants in an automobile is significantly decreased due to the thermal transfer from the air generated by the HVAC assembly to the surrounding air. Therefore, only part of the temperature exchange is directed toward to the vehicle occupant. 
     The optimum effect is attained by applying the conditioned air as directly as possible to the vehicle occupant. This is accomplished by delivering conditioned air to the occupant seat from a known source like the HVAC assembly or a thermoelectric cooler/heater disposed within the seat, as illustrated in U.S. Pat. No. Re. 38,128 to Gallup et al., U.S. Pat. No. 5,924,766 to Esaki et al., and U.S. Pat. No. 6,079,485 to Esaki et al., and PCT application WO 99/58907 to Bell. 
     The air from the HVAC assembly on initial startup is not thermally conditioned. In the case of heating, it takes time to warm the coolant due to the thermal inertia of the engine. In the case of cooling, it takes time the traditional A/C cycle to cool air. When initiating the warm-up mode, the occupant is typically not satisfied with the warming effect immediately generated at start-up. Similarly, when initiating the cool-down mode, the occupant is typically not satisfied with the immediate cooling effect. The adverse effect caused by the natural temperature transient that exists at start-up may be resolved by providing an auxiliary air-conditioning device in the ductwork between the HVAC module and the seat passages of the seat assembly for exchanging preconditioned air generated by the HVAC assembly to achieve a faster warming and/or cooling effect desired by the occupant, as disclosed in U.S. Pat. No. 7,238,101 to Kadle et al. Although an auxiliary air-conditioning device can increase the warming and/or cooling effect desired by the occupant, the additional air-conditioning device increases vehicle cost. Further, the additional air-conditioning device increases power consumption, thereby decreasing the overall energy efficiency of the vehicle. 
     SUMMARY OF THE INVENTION AND ADVANTAGES 
     In addition to the structure described above, this invention provides for a control system for opening a purge valve and closing one or more seat valves in response to the air temperature from the HVAC assembly being less than a predetermined temperature. Furthermore, the control system closes the purge valve and opens at least one seat valve to deliver air from the air selection module to the seat assembly in response to the air temperature being at least the predetermined air temperature. Accordingly, the occupant is exposed to air having at least the predetermined air temperature desired. 
     The invention provided leverages the traditionally HVAC assembly to increase the warming and/or cooling effect desired by the vehicle occupant, thereby decreasing vehicle costs while increasing energy efficiency. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
         FIG. 1  is a perspective view of an automotive vehicle including a control system for thermally heating and/or cooling a vehicle seat according to the present invention; 
         FIGS. 2 and 3  are partial views of the automotive vehicle including a control system for delivering air to a vehicle occupant according to the present invention; 
         FIG. 4  is a flowchart illustrating a method of warming an occupant of an automotive vehicle according to the present invention; and 
         FIG. 5  is flowchart illustrating a method of cooling an occupant of an automotive vehicle according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, an automotive vehicle  20  is generally shown including a body  22  defining a occupant cabin  24 . A seat assembly  26  is generally indicated and is disposed in the occupant cabin  24 . The seat assembly  26  includes a seat bottom  28  and a seat back  30  for holding an occupant therein. The seat bottom  28  and the seat back  30  have a plurality of seat outlets  32  for exhausting air to the occupant seated in the seat assembly  26 . The seat bottom  28  includes a seat bottom inlet  34  and the seat back  30  includes a seat back inlet  36 . The seat bottom inlet  34  receives air and delivers the air into the seat bottom  28 . The air within the seat bottom  28  is expelled through the seat outlets  32  such that air can be delivered to the lower half of the occupant. Similarly, the seat back inlet  36  receives air and delivers air into seat back  30  such that air is expelled through the seat outlets  32  such that air is exhausted to the upper half of the occupant. 
     The automotive vehicle  20  includes a temperature selector  29 , an HVAC assembly  38  supported by the body  22  of the automotive vehicle  20  for generating thermally conditioned air, and an air temperature sensor  40 . The temperature selector  29  is operable by the occupant for selecting a predetermined air temperature (T PRE ). The predetermined air temperature (T PRE )is indicative of the air temperature (T AIR ) the occupant desires to be exhausted from the seat assembly  26 . In response to selecting the predetermined air temperature (T PRE ), a predetermined air temperature (T PRE ) signal is output by the temperature selector indicating the predetermined air temperature (T PRE ). 
     The HVAC assembly  38  is initiated to generate air in response to either a warm-up signal or a cool-down signal. In addition to selecting the predetermined air temperature (T PRE ) the temperature selector  29  can be used to select the warm-up mode and the cool-down mode. An occupant selects the warm-up mode with a desire to receive heated air from the seat assembly  26 . Similarly, the occupant selects the cool-down mode with a desire to receive cooled air from the seat assembly  26 . The purpose of HVAC assembly  38  while operating in either mode is to generate air that will attain the predetermined air temperature (T PRE ) selected by the occupant. 
     The air temperature sensor  40  is disposed downstream from the HVAC assembly  38  and within the HVAC duct  42  for sensing the temperature of the air generated by the HVAC assembly  38 . Although  FIGS. 2 and 3  show the air temperature sensor  40  disposed within the HVAC duct  42 , it is appreciated that the temperature sensor may be disposed further downstream from the HVAC assembly  38 , such within the air selection module  44 . Furthermore, a temperature sensor may be disposed within each of the seat bottom duct  46 , the seat back duct  48 , and the purge duct  50  to detect the corresponding temperature therein. In response to sensing the air temperature (T AIR ), the air temperature sensor  40  outputs an air temperature (T AIR ) signal. The air temperature (T AIR ) signal can be used to determine whether the air from the HVAC has attained the predetermined air temperature (T PRE ). 
     Referring to  FIGS. 2 and 3 , the automotive vehicle  20  further includes an air selection module  44  supported by the body  22  and disposed beneath the seat assembly  26  for controlling airflow from the HVAC assembly  38 , as discussed further below. The automotive vehicle  20  includes ductwork for delivering air to and from the air selection module  44 . Specifically, an HVAC duct  42  extends from the HVAC assembly  38  to the air selection module  44  for delivering air from the HVAC assembly  38  to the air selection module  44 . A seat bottom duct  46  and a seat back duct  48  deliver air from the air selection module  44  to the seat assembly  26 . The seat bottom duct  46  extends from the air selection module  44  to the seat bottom inlet  34  for delivering the air from the air selection module  44  into the seat bottom  28 . The seat back duct  48  extends from the air selection module  44  to the seat back inlet  36  for delivering the air from the air selection module  44  into the seat back  30 . 
     Seat valves  52 ,  54  are integrated with both the seat bottom duct  46  and the seat back duct  48  and operate in response to one or more control signals. The seat valves  52 ,  54  operate in an open position for allowing airflow to the seat ducts  42 ,  46 ,  48 ,  50  and in a closed position for blocking airflow to the seat ducts  42 ,  46 ,  48 ,  50 . Specifically, a seat bottom valve  52  is disposed between the seat bottom duct  46  and the air selection module  44  for opening in response to a seat bottom open signal (SEATBOTTOM OPEN ) and for closing in response to a seat bottom close signal (SEATBOTTOM CLOSE ) to regulate the delivery of air to the seat bottom duct  46 . A seat back valve  54  is disposed between the seat back duct  48  and the air selection module  44  for opening in response to a seat back open signal (SEATBACK OPEN ) and for closing in response to a seat back close signal (SEATBACK CLOSE ) to regulate the delivery of air to the seat back duct  48 . 
     The air selection module  44  includes a purge duct  50  having a purge valve  56  for controlling airflow therethrough. The purge duct  50  extends along the body  22  and beneath the seat assembly  26  for exhausting air from the air selection module  44  and for diverting air away from the seat ducts. The purge valve  56  is disposed between the purge duct  50  and the air selection module  44  and moves between an open position and a closed position in response to one or more control signals. Specifically, the purge valve  56  opens in response to a purge open signal (PURGE OPEN ) for venting air from the air selection module  44  and a closed position in response to the purge close signal (PURGE CLOSE ) for blocking airflow through the purge duct  50 . 
     When the occupant desires air to be delivered from the seat assembly  26 , the occupant selects the operating mode of the HVAC assembly  38  and the corresponding predetermined temperature. The HVAC assembly  38  is initiated and generates air in response to either the warm-up signal or the cool-down signal. The air is delivered to the air selection module  44  via the HVAC duct  42 . Once delivered to the air selection module  44 , airflow is either blocked from entering the seat assembly  26  and vented from the air selection module  44  or is delivered to the seat assembly  26  where it is exhausted from the seat outlets  32 . When both the seat bottom valve  52  and the seat back valve  54  are closed while the purge valve  56  is opened, airflow to the seat bottom duct  46  and seat back  30  is blocked and air is vented from the air selection module  44 . Accordingly, air is blocked from being delivered to the seat assembly  26  and is prevented from being exhausted to the occupant. However, when both the seat bottom valve  52  and the seat back valve  54  are open while the purge valve  56  is closed, air is delivered to the seat bottom  28  and seat back  30  via the seat bottom duct  46  and the seat back duct  48 , thereby allowing air to be exhausted from the seat outlets  32  to thermally condition the occupant. 
     The automotive vehicle  20  further includes a heat element assembly for emitting heat to warm the seat assembly  26  and the occupant seated therein. The heat element assembly is disposed in the seat assembly  26  for heating the seat assembly  26  in response to an energizing signal (HEAT ON ). The heat element assembly includes a power supply  58  and a plurality of heating elements  60  connected to the power supply  58  and disposed with each of the seat bottom  28  and seat back  30 . The energizing signal (HEAT ON ) switches on the power supply  58  for generating current to the heating elements  60 . In response to the current, the heating elements  60  emit heat that warms the seat bottom  28  and seat back  30 . A seat temperature sensor  64  is disposed within the seat assembly  26  for sensing a seat temperature (T SEAT ) of the seat assembly  26  and for outputting a seat temperature (T SEAT ) signal in response to sensing the seat temperature (T SEAT ). 
     The automotive vehicle  20  is distinguished by a control system  62  for opening and closing the purge valve  56 , the seat bottom valve  52 , and the seat back valve  54  in response to a comparison between the temperature of the air generated by the HVAC assembly  38  and the predetermined air temperature (T PRE ) selected by the occupant. The control system  62  includes a HVAC controller  66  in signal communication with the air temperature T AIR  selector  29 , the HVAC assembly  38  and the air selection module  44 . The HVAC controller  66  receives the predetermined air temperature (T PRE ) from the air temperature (T AIR ) selector and outputs either the warm-up signal or the cool-down signal that initiates the HVAC assembly  38  for generating air to achieve the predetermined air temperature (T PRE ). 
     The HVAC controller  66  receives the air temperature (T AIR ) signal from the air temperature sensor  40  indicating the air temperature (T AIR ) of the air generated by the HVAC assembly  38 . The HVAC controller  66  compares the air temperature (T AIR ) to the predetermined air temperature (T PRE )and outputs one or more control signals to the air selection module  44  to open and/or close the purge valve  56 , the seat bottom valve  52  and the seat back valve  54 . As stated earlier, the position of the valves  52 ,  54  regulates the airflow delivered to the purge duct  50 , the seat bottom duct  46  and the seat back duct  48  to ensure the air delivered from the seat outlets  32  at the predetermined air temperature (T PRE ) selected by the occupant, as discussed further below. 
     The HVAC controller  66  outputs a purge open signal (PURGE OPEN ), a seat bottom close signal (SEATBOTTOM CLOSE ) and a seat back close signal (SEATBACK CLOSE ) in response to the air temperature (T AIR ) generated by the HVAC assembly  38  being less than the predetermined air temperature (T PRE ) selected by the occupant. The purge open signal (PURGE OPEN ) opens the purge valve  56  to vent air from the air selection module  44 . The seat bottom close signal (SEATBOTTOM CLOSE ) and the seat back close signal (SEATBACK CLOSE ) close the seat bottom valve  52  and the seat back valve  54 , respectively, to block airflow to the seat bottom duct  46  and seat back duct  48 . Similarly, the control module outputs a purge close signal (PURGE CLOSE ), a seat bottom open signal (SEATBOTTOM OPEN ) and a seat back open signal (SEATBACK OPEN ) in response to the air temperature (T AIR ) being at least the predetermined air temperature (T PRE ). The purge close signal (PURGE CLOSE ) closes the purge valve  56  to block airflow through the purge duct  50 . The seat bottom open signal (SEATBOTTOM OPEN ) and the seat back open signal (SEATBACK OPEN ) open the seat bottom  28  vent and the seat back  30  vent, respectively, to deliver air from the air selection module  44  to the seat bottom duct  46  and seat back duct  48 . As a result, the occupant is exposed to air from the seat outlets  32  only when the air temperature (T AIR ) from the HVAC assembly  38  is at least the predetermined air temperature (T PRE ) selected by the occupant. 
     The HVAC controller  66  is also in signal communication with the heated seat assembly  26  and the seat temperature sensor  64  to warm the occupant when the HVAC assembly  38  operates in the warm-up mode and while the airflow through the air selection module  44  attains at least the predetermined air temperature (T PRE ). The HVAC controller  66  outputs an energizing signal (HEAT ON ) to switch on the power supply  58  in response to the occupant selecting the warm-up mode. The HVAC controller  66  outputs a de-energizing signal (HEAT OFF ) to switch off the power supply  58  in response to the air temperature (T AIR ) being at least the predetermined air temperature (T PRE ) and/or the seat temperature (T SEAT ) being at least a predetermined seat temperature (T SEAT ). The HVAC controller  66  can also de-energize the heated seat assembly  26  when the occupant selects the HVAC assembly  38  to operate in the cool-down mode. Accordingly, the control system  62  leverages the traditionally HVAC assembly  38  to increase the warming and/or cooling effect desired by the vehicle occupant, thereby decreasing vehicle costs while increasing energy efficiency. 
     Referring to  FIGS. 4 and 5 , flowcharts illustrating a method of thermally conditioning an occupant located in a occupant cabin  24  of an automotive vehicle  20  are generally shown. The automotive vehicle  20  includes a seat assembly  26  having a seat bottom  28  and a seat back  30 . Both the seat bottom  28  and the seat back  30  have seat outlets  32  for delivering air existing at a predetermined air temperature (T PRE ) to the occupant seated therein. An electrically operated heat element assembly is disposed in the seat assembly  26  for emitting heat in response to current for heating the seat assembly  26 . The automotive vehicle  20  includes a temperature selector  29  operable by the occupant for selecting the predetermined air temperature (T PRE ). A HVAC assembly  38  is provided for generating air to achieve the predetermined air temperature (T PRE ). The HVAC assembly  38  operates in at least one of a warm-up mode and a cool-down mode. The occupant selects the warm-up to generate heated air. Similarly, the occupant selects the cool-down mode to generate cooled air. The automotive vehicle  20  further includes an air selection module  44  having a purge valve  56  operable in an open and closed position for controlling airflow from air selection module  44 . The air selection module  44  also includes a seat bottom valve  52  for controlling airflow to the seat bottom  28  and a seat back valve  52 ,  54  for controlling airflow to the seat back  30 . 
     Referring to  FIG. 4 , a method for warming the occupant begins at step and proceeds by selecting a warm-up mode in step. The warm-up mode can be selected using the temperature selector  29 , which initiates the HVAC assembly  38  to generate air. In step, a predetermined air temperature (T PRE ) is selected. The vehicle occupant can use the temperature selector  29  to select the predetermined air temperature (T PRE ). The method proceeds to step by energizing the heat element assembly to warm the occupant while air generated by an HVAC assembly  38  attains the selected predetermined air temperature (T PRE ). For example, an energizing signal (HEAT ON ) may switch on a power supply  58  that generates current. The heat element assembly may utilize the current to emit heat and warm the seat assembly  26 . In step the seat bottom valve  52  and seat back valve  54  are closed and in step the purge valve  56  is opened. Air from the HVAC assembly  38  is delivered through the purge valve  56  in step to vent air from the air selection module  44 . In step, the air temperature (T AIR ) from the HVAC assembly  38  is compared to the predetermined air temperature (T PRE ). When the air temperature (T AIR ) is below the predetermined air temperature (T PRE ), the method returns to step and continues to vent air through the purge valve  56 . When the air temperature (T AIR ) from the HVAC assembly  38  is at least the predetermined air temperature (T PRE ), the purge valve  56  is closed in step. The method proceeds to step by opening the seat bottom valve  52  and the seat back valve  54  to deliver air having at least the predetermined air temperature (T PRE ) to the occupant. The method de-energizes the heat element assembly in step and allows air exhausted from the seat outlets  32  to thermally condition the occupant. The method ends at step. As a result, the air is exhausted from the seat outlets  32  only when the air generated by the HVAC assembly  38  has reached the predetermined air temperature (T PRE ) selected by the occupant. 
     Referring to  FIG. 5 , a method for cooling the occupant begins at step and proceeds by selecting a cool-down mode to initiate the HVAC assembly  38  to generate cool air in step. In step, a predetermined air temperature (T PRE ) is selected by the occupant. In step, the heat element assembly is automatically de-energized to accelerate the cooling effect. In step, the seat bottom valve  52  and seat back valve  54  are closed and in step the purge valve  56  is opened. Air from the HVAC assembly  38  is delivered through the purge valve  56  in step to vent air form the air selection module  44 . Accordingly, air having an undesired temperature is blocked from flowing over the occupant. In step, the temperature of the air from the HVAC assembly  38  is compared to the predetermined air temperature (T PRE ). If the air temperature (T AIR ) is below the predetermined air temperature (T PRE ), the method returns to step and continues delivering air through the purge valve  56 . If the air temperature (T AIR ) from the HVAC assembly  38  is at least the predetermined air temperature (T PRE ), the purge valve  56  is closed in step. The method proceeds to step by opening the seat bottom valve  52  and the seat back valve  54  to deliver air from the seat outlets  32 . The method ends at step. Therefore, air is exhausted from the seat outlets  32  only when the air generated by the HVAC assembly  38  has reached the predetermined air temperature (T PRE ) selected by the occupant. 
     While the invention has been described with reference to an exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.