Abstract:
A vehicle having a cowl tray and a Heating, Ventilation, and Air Conditioning (HVAC) system is provided with one or more coolant-to-air heat exchangers near the intake opening of the HVAC system or attached to the cowl tray, in order to prevent an accumulation of snow and ice from blocking the flow of intake air into the HVAC system and interfering with the windshield wiper system. The accumulation of snow and ice in the HVAC intake is a problem commonly experienced by vehicles having the HVAC intake located near the base of the vehicle windshield, due to turbulent precipitation.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to the use of one or more coolant-to-air heat exchangers in conjunction with a cowl tray and a Heating, Ventilation, and Air Conditioning (HVAC) intake. The coolant-to-air heat exchangers are used to prevent accumulation of snow and ice, both within the intake itself, and upon the cowl tray beneath the vehicle windshield wipers. The HVAC intake may be integrated directly into the cowl tray, which cowl tray and intake may be located at the base of the vehicle windshield in a location prone to snow and ice accumulation, due to the action of the vehicle windshield wipers, and due to turbulent precipitation. 
   2. Description of the Related Art 
   Ground traveling vehicles having an occupant cabin are almost universally equipped with some form of Heating, Ventilation, and Air Conditioning (HVAC) system. This system functions to draw air from outside the occupant cabin, heat or cool it to a comfortable temperature, and introduce it into the occupant cabin. The air intake for the HVAC system may be placed at any of a number of locations external to the cabin. However, there are several advantages to locating the intake at the base of the vehicle windshield. 
   As a ground traveling vehicle moves, it displaces air. Relative to the frame of reference of the moving vehicle, the air flows past the vehicle. This airflow is laminar in some locations, turbulent in others, and at various angles oblique to the direction of travel depending on the geometry of the vehicle body, resulting in regions of high and low pressure. One location that exhibits consistently high pressure is at the base of the windshield, where the moving air must make a transition from the angle of the hood to the angle of windshield. This area is characterized by a region of turbulent recirculation, and somewhat elevated static pressure. For this reason, the HVAC air intake is often there located. In the same way, vehicle manufacturers have in the past located the vehicle engine air intake in the same area. Often, this was referred to as cowl induction. 
   An advantage to locating the HVAC air intake in a region of elevated static pressure is the fact that so doing provides greater airflow through the HVAC system and into the cabin. Even when the HVAC blower is not operating, a system having its air intake so located provides positive pressure within the vehicle cabin, thereby minimizing draft incursions and water seepage through and around the various seals and seams that are characteristic of a vehicle occupant cabin. Locating the HVAC air intake at the base of the windshield has other advantages as well. The airflow at this point is well up and away from the level at which vehicle exhaust is commonly discharged. The intake may be discreetly hidden from view by the vehicle hood. Additionally, the base of the windshield is proximate to the HVAC air distribution plenum, eliminating the need for lengthy ductwork. 
   There is, however, a disadvantage to having the HVAC air intake located at the base of the vehicle windshield. When moving air enters a region of turbulent recirculation, it tends to precipitate anything held in suspension. In order to deal with this effect, U.S. Pat. No. 6,868,928 teaches the use of a cowl tray, which catches and drains away moisture, although in the case of the invention taught in U.S. Pat. No. 6,868,928, the region of elevated static pressure is being utilized in an engine cowl induction system. Although the cowl tray taught in U.S. Pat. No. 6,868,928 deals well with liquid water precipitate, snow and ice accumulation at the base of the vehicle windshield continues to be a problem. The snow and ice often packs the cowl tray full, so that the windshield wipers cannot freely complete their range of motion. Snow and ice also tends to enter the HVAC intake, restricting airflow. 
   The situation of snow and ice entering the HVAC air intake is exacerbated by the fact that the opening of the HVAC air intake is relatively large and oriented vertically, in order to facilitate ease of routing and maximize airflow. Usually, some sort of intake screen is provided, in order to prevent leaves and other large debris from entering the HVAC system. This screen tends to be the point at which snow and ice accumulates. Further, the windshield wipers tend to push at least some snow into the area of recirculation and even directly into the HVAC air intake itself. Under certain conditions, sufficient snow and ice may accumulate to completely block the intake, reducing the amount of airflow available for heating and defrosting the vehicle windows. 
   SUMMARY OF THE INVENTION 
   It is the object of the present invention to eliminate the problem of snow and ice accumulation upon the cowl tray and within the HVAC air intake by providing sufficient heat to melt the snow and ice as it is deposited. In order to accomplish this, one or more small engine coolant-to-air heat exchangers are used. A single heat exchanger may be located within the HVAC air intake, proximate to the opening in the cowl tray or equivalent structure. Alternatively to, or in conjunction with, the single heat exchanger within the HVAC intake, one or more heat exchangers may be attached to the upper surface of the cowl tray, extending along its length beneath the base of the windshield and the windshield wipers. Small diameter hose or tubing is used to supply heated engine coolant to the heat exchanger or heat exchangers, which small diameter hose or tubing may be provided with tube insulation to maximize the temperature of the coolant available to the heat exchanger or heat exchangers. The routing of engine coolant to the engine coolant-to-air heat exchanger or heat exchangers may be in series, in parallel, or completely separate from the heater core of the HVAC system. 
   In order to regulate the flow of coolant to the heat exchanger or heat exchangers, a valve may be present in the coolant supply hose or tubing. This valve may be accessible only from under the vehicle hood, or it may be remotely operated from within the vehicle cab. Further, it may be operated automatically in conjunction with one or more sensors that determine the presence of snow and ice in the HVAC intake. Alternately, automatic operation of the valve may be based on ambient conditions, rather than direct sensing of snow and ice in the HVAC intake. 
   The engine coolant-to-air heat exchanger or heat exchangers may be of simple tube-and-fin construction, as such heat exchangers are known in the art. Such small tube-and-fin heat exchangers are commonly utilized as power steering coolers, transmission coolers, and the like. In this embodiment, the heat exchanger or heat exchangers rely upon direct proximity to the location of snow and ice accumulation to cause the snow and ice to melt. Alternately, the engine coolant-to-air heat exchanger or heat exchangers may be constructed to maximize radiant heat emission. This embodiment is designed to overcome the limitations on convective heat transfer to the accumulated snow and ice imposed by the fact that the engine coolant-to-air heat exchanger mounted within the HVAC intake is at least partially downstream from the opening, and the engine coolant-to-air heat exchanger or heat exchangers mounted upon the cowl tray are exposed to rapid air movement. A radiant heat exchanger of this type may be constructed as an array of one or more heat transfer tubes coated with a radiantly emissive coating. Further, the radiant coolant-to-air heat exchanger or heat exchangers may be provided with one or more reflectors, in order to attenuate the radiant heat upon the accumulated snow and ice. 
   In another embodiment, the engine coolant-to-air heat exchanger or heat exchangers are mounted to a thermally conductive structure or structures which may be incorporated into the HVAC intake, or may be attached to the cowl tray. The thermally conductive structure or structures may be constructed of aluminum or other thermally conductive material, and may extend from the mounting location of the engine coolant-to-air heat exchanger to the point of accumulation of snow and ice. A thermally conductive structure used in conjunction with a engine coolant-to-air heat exchanger located within the HVAC intake opening may be in direct communication with the HVAC intake screen. 
   As in the prior art, water control and drainage is provided within the HVAC air intake in the form of labyrinthine intake geometry, sharp transitions, weep holes, and duckbills. In this way, the present invention accommodates the runoff from the melting snow and ice. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG.  1 —Vehicle having region of air recirculation and increased static pressure at base of windshield near cowl. 
     FIG.  2 —Partial view of vehicle having HVAC intake located near base of windshield and within cowl tray. 
     FIG.  3 —Vehicle experiencing snow accumulation at base of windshield due to turbulent precipitation. 
     FIG.  4 —A view of a first embodiment of the present invention. 
     FIG.  5 —A view of a second embodiment of the present invention. 
     FIG.  6 —A view of a third embodiment of the present invention. 
     FIG.  7 —A view of a fourth embodiment of the present invention. 
     FIG.  8 —A view of a fifth embodiment of the present invention. 
     FIG.  9 —A view of a sixth embodiment of the present invention. 
     FIG.  10 —A view of a seventh embodiment of the present invention. 
     FIG.  11 —A view of an eighth embodiment of the present invention. 
   

   DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a vehicle  101  having a chassis  103 , a cab  104 , a windshield  106 , and a hood  105 .  FIG. 1  further shows air flow  110  moving past the vehicle  101 . A region of recirculation  111 , exhibiting increased static pressure, exists near the base of the windshield  106 . 
     FIG. 2  shows a partial view of a vehicle  101  having an engine  102 , a chassis  103 , and a cab  104 . The hood  105  of vehicle  101  is not shown in  FIG. 2 . The cab  104  of vehicle  101  has a windshield  106  and windshield wipers  107 . Below the windshield  106  and separating occupants of the cab  104  from the engine  105 , is a cowl  108 . A cowl tray  109  located upon the cowl  108  at the base of the windshield  106  provides drainage of moisture runoff from the windshield  106  and hood  105  (not shown). Connected to the cowl tray  109  is an HVAC system  113 , which provides heated or cooled air to the occupants of the cab  104 . An HVAC intake opening  114  is integrated into the cowl tray  109 , and is provided with an HVAC intake screen  115 . 
     FIG. 3  shows a vehicle  101  having a chassis  103 , a cab  104 , a hood  105 , and a windshield  106 . Air flow  110  relative to the vehicle  101  makes a transition from a direction approximately parallel to the hood  105  of the vehicle  101  to a direction approximately parallel to the windshield  106 . The change in direction of the air flow  110  results in a region of air recirculation  111 . This region of air recirculation  111  deposits snow and ice  112  near the base of the windshield  106 . The location of the snow and ice  112  deposit overlies the cowl tray  109  (not shown) and HVAC intake opening  114  (not shown) as they are shown in  FIG. 2 . The windshield  106  shown in  FIG. 3  is further provided with a set of windshield wipers  107 , which windshield wipers  107  tend to push additional snow and ice  112  towards the base of the windshield  106 . 
     FIG. 4  shows a partial view of a vehicle  101  having an engine  102 , a chassis  103 , and a cab  104 , similar to the vehicle  101  shown in  FIG. 2 . The hood  105  of vehicle  101  is not shown in  FIG. 4 . The cab  104  of the vehicle  101  shown in  FIG. 4  is again provided with a windshield  106 , windshield wipers  107 , a cowl  108 , and a cowl tray  109 . An HVAC system  113  connects to the cowl tray  109 , passes through the cowl  108 , and into the interior of the cab  104 , in order to provide heated or cooled air to the occupants thereof. Air enters the HVAC system  113  at the HVAC intake opening  114 , which is integrated into the cowl tray  109 . The HVAC intake opening  114  is protected against the entry of large debris by means of the HVAC intake screen  115 . An embodiment of the present invention, a tube-and-fin type coolant-to-air heat exchanger  119  is located within the HVAC intake opening  114 , proximate to the HVAC intake opening  114  and HVAC intake screen  115 . The cowl tray  109  is shown partially cut-away, so that the tube-and-fin type coolant-to-air heat exchanger  119  may be more clearly illustrated. Coolant lines  120  carry heated engine coolant from the engine  102  to the tube-and-fin type coolant-to-air heat exchanger  119 . In order to increase efficiency, tube insulation  121  may be provided. In the embodiment of the present invention shown in  FIG. 4 , a manual underhood control valve  122  controls the availability of heated coolant to the tube-and-fin type coolant-to-air heat exchanger  119 . 
     FIG. 5  shows a partial view of a vehicle  101  having a cab  104 , a windshield  106 , windshield wipers  107 , a cowl  108 , and a cowl tray  109 , similar to the vehicle  101  shown in  FIG. 4 . The hood  105  of vehicle  101  is not shown in  FIG. 5 . An HVAC system  113  again connects to the cowl tray  109 , passes through the cowl  108 , and into the interior of the cab  104 , in order to provide heated or cooled air to the occupants thereof. Air enters the HVAC system  113  at the HVAC intake opening  114 , which is integrated into the cowl tray  109 , and is provided with an HVAC intake screen  115 . An embodiment of the present invention, a coolant-to-air radiant heat exchanger  130  is located within the HVAC intake opening  114 , proximate to the HVAC intake opening  114  and HVAC intake screen  115 . The cowl tray  109  is shown partially cut-away, so that the coolant-to-air radiant heat exchanger  130  may be more clearly illustrated. The tubes of the coolant-to-air radiant heat exchanger  130  are coated with a heat emissive coating  131 . Radiant heat reflectors  132  attenuate and focus radiant heat produced by the coolant-to-air radiant heat exchanger  130  in the direction of the HVAC intake screen  115 . Coolant lines  120  carry heated engine coolant from the engine  102  (not shown) to the coolant-to-air radiant heat exchanger  130 . In order to increase efficiency, tube insulation  121  may be provided. 
     FIG. 6  shows a partial view of a vehicle  101  having a cab  104 , a windshield  106 , windshield wipers  107 , a cowl  108 , and a cowl tray  109 , similar to the vehicles  101  shown in  FIG. 4  and  FIG. 5 . The hood  105  of vehicle  101  is not shown in  FIG. 6 . An HVAC system  113  connected to the cowl  108  and the cowl tray  109  is again provided having an HVAC intake opening  114  and an HVAC intake screen  115 . Another embodiment of the present invention, a conductive heat exchanger  134 , is located within the HVAC intake opening  114 , and is in communication with the HVAC intake screen  115  by means of a heat conductive structure  135 . The heat exchanger  134  and heat conductive structure  135  are constructed of a material having a relatively high coefficient of thermal conductivity, such as aluminum. Again, the cowl tray  109 , HVAC intake opening  114 , and HVAC intake screen  115  are shown partially cut-away, so that the conductive heat exchanger  134  and heat conductive structure  135  may be more clearly illustrated. Coolant lines  120  carry heated engine coolant from the engine  102  (not shown) to the conductive heat exchanger  134 . In order to increase efficiency, tube insulation  121  may be provided. 
     FIG. 7  shows a partial view of a vehicle  101  having a cab  104 , an engine  102 , a cowl  108 , and a cowl tray  109 , similar to the vehicles  101  shown in  FIGS. 4-6 . The hood  105  of vehicle  101  is not shown in  FIG. 7 . The cab  104  is shown partially removed for clarity, and in the same way the windshield  106  is not shown, although the windshield wipers  107  are partially shown in the installed position. An HVAC system  113  connected to the cowl  108  and the cowl tray  109  is again provided having an HVAC intake opening  114  and an HVAC intake screen  115 . The HVAC system  113  shown in  FIG. 7  additionally shows several components interior to the cab  104 , specifically an HVAC air distribution plenum  116 , which HVAC air distribution plenum  116  is partially cut-away to show an HVAC heater core  118 . The HVAC heater core  118  is a type of coolant-to-air heat exchanger well known in the art. An embodiment of the present invention, a tube-and-fin type coolant-to-air heat exchanger  119  is located within the HVAC intake opening  114 , proximate to the HVAC intake opening  114  and HVAC intake screen  115 . The cowl tray  109  is shown partially cut-away, so that the tube-and-fin type coolant-to-air heat exchanger  119  may be more clearly illustrated. For the sake of illustration, a tube-and-fin type coolant-to-air heat exchanger  119  is shown in  FIG. 7 , similar to the tube-and-fin type coolant-to-air heat exchanger  119  shown in  FIG. 4 , although the heat exchanger may also be a coolant-to-air radiant heat exchanger  130  as in  FIG. 5 , or a conductive heat exchanger  134  as in  FIG. 6 , as the object of  FIG. 7  is to illustrate the coolant routing configuration of the coolant lines  120 , independent of the type of HVAC intake heater utilized. The flow of coolant through the tube-and-fin type coolant-to-air heat exchanger  119  and through the HVAC heater core  118  is in series configuration. Specifically, a coolant supply line  120   a  carries coolant from the engine  102  to the tube-and-fin type coolant-to-air heat exchanger  119 , an exchanger to exchanger coolant line  120   c  carries coolant from the tube-and-fin type coolant-to-air heat exchanger  119  to the HVAC heater core  118 , and a coolant return line  120   b  carries coolant from the HVAC heater core  118  back to the engine  102 . Alternately, it is within the scope of the present invention that the flow may be in reverse, so that the coolant passes through the HVAC heater core  118  prior to passing through the tube-and-fin type coolant-to-air heat exchanger  119 . 
     FIG. 8  shows a partial view of a vehicle  101  having a cab  104 , an engine  102 , a cowl  108 , and a cowl tray  109 , similar to the vehicle  101  shown in  FIG. 7 . The hood  105  of vehicle  101  is not shown in  FIG. 8 . The cab  104  is again shown partially removed for clarity, with the windshield  106  removed and the windshield wipers  107  partially shown. An HVAC system  113  connected to the cowl  108  and the cowl tray  109  is provided having an HVAC intake opening  114 , an HVAC intake screen  115 , an HVAC air distribution plenum  116 , and an HVAC heater core  118 . An embodiment of the present invention, a tube-and-fin type coolant-to-air heat exchanger  119  is located within the HVAC intake opening  114 , proximate to the HVAC intake opening  114  and HVAC intake screen  115 . Both the HVAC air distribution plenum  116  and the cowl tray  109  are shown partially cut-away, so that the HVAC heater core  118  and the tube-and-fin type coolant-to-air heat exchanger  119  may be more clearly illustrated. In the same manner as in  FIG. 7 , a tube-and-fin type coolant-to-air heat exchanger  119  is shown in  FIG. 8 , similar to the tube-and-fin type coolant-to-air heat exchanger  119  shown in  FIG. 4 , although the heat exchanger may also be a coolant-to-air radiant heat exchanger  130  as in  FIG. 5 , or a conductive heat exchanger  134  as in  FIG. 6 , as the object of  FIG. 8  is to illustrate the coolant routing configuration of the coolant lines  120 , independent of the type of HVAC intake heater utilized. The flow of coolant through the tube-and-fin type coolant-to-air heat exchanger  119  and through the HVAC heater core  118  is in parallel configuration. Specifically, a coolant supply line  120   a  carries coolant from the engine  102  to the tube-and-fin type coolant-to-air heat exchanger  119 , as well as to the HVAC heater core  118 . A coolant return line  120   b  carries coolant from the HVAC heater core  118  and from the tube-and-fin type coolant-to-air heat exchanger  119  back to the engine  102 . 
     FIG. 9  shows a partial view of a vehicle  101  having an engine  102 , a chassis  103 , a cab  104 , a windshield  106 , windshield wipers  107 , a cowl  108 , and a cowl tray  109 , similar to the vehicle  101  shown in  FIG. 4 . The hood  105  of vehicle  101  is not shown in  FIG. 9 . An HVAC system  113  connected to the cowl  108  and the cowl tray  109  is provided having an HVAC intake opening  114  and an HVAC intake screen  115 . An embodiment of the present invention, a tube-and-fin type coolant-to-air heat exchanger  119  is located within the HVAC intake opening  114 , proximate to the HVAC intake opening  114  and HVAC intake screen  115 . The cowl tray  109  is shown partially cut-away, so that the tube-and-fin type coolant-to-air heat exchanger  119  may be more clearly illustrated. Coolant lines  120  carry heated engine coolant from the engine  102  to the tube-and-fin type coolant-to-air heat exchanger  119 . In order to increase efficiency, tube insulation  121  may be provided. In the embodiment of the present invention shown in  FIG. 9 , a remotely controlled valve  123  controls the availability of heated coolant to the tube-and-fin type coolant-to-air heat exchanger  119 . The remotely controlled valve  123  is connected to an in-cab control  127  by a valve control line  128 , which valve control line  128  may be a vacuum line, an air pressure line, an electrical conductor, or a Bowden cable. The remotely controlled valve  123  itself, then, may be pressure actuated, vacuum actuated, electrically actuated, or cable actuated. The remotely controlled valve  123  of the type shown in  FIG. 9  may also be used with a coolant-to-air radiant heat exchanger  130  (not shown) or a conductive heat exchanger  134  (not shown). 
     FIG. 10  shows a partial view of a vehicle  101  having an engine  102 , a chassis  103 , a cab  104 , a windshield  106 , windshield wipers  107 , a cowl  108 , and a cowl tray  109 , similar to the vehicle  101  shown in  FIG. 4 . The hood  105  of vehicle  101  is shown in dotted lines in  FIG. 10 , so that the underhood components may be illustrated. An HVAC system  113  connected to the cowl  108  and the cowl tray  109  is provided having an HVAC intake opening  114  and an HVAC intake screen  115 . An embodiment of the present invention, a tube-and-fin type coolant-to-air heat exchanger  119  is located within the HVAC intake opening  114 , proximate to the HVAC intake opening  114  and HVAC intake screen  115 . The cowl tray  109  is shown partially cut-away, so that the tube-and-fin type coolant-to-air heat exchanger  119  may be more clearly illustrated. Coolant lines  120  carry heated engine coolant from the engine  102  to the tube-and-fin type coolant-to-air heat exchanger  119 . In the embodiment of the present invention shown in  FIG. 10 , an automatically controlled valve  124  controls the availability of heated coolant to the tube-and-fin type coolant-to-air heat exchanger  119 . Snow and ice sensors  125  detect the presence of snow or ice near the base of the windshield  106 . One or more ambient conditions sensors  126  may sense the ambient conditions surrounding the vehicle  101 , in order to determine if conditions are favorable for the formation of snow and ice. The snow and ice sensors  125  and the ambient conditions sensors  126  are connected to a controller  137 , which controller  137  is connected to the automatically controlled valve  124  by the valve control line  128 . Alternately, the controller  137  may be entirely integrated into the automatically controlled valve  124 . If the snow and ice sensors  125  or the ambient conditions sensors  126  detect the presence of, or conditions favorable for the presence of, an accumulation of snow or ice, the automatically controlled valve  124  is directed by the controller  137  to provide heated coolant to the tube-and-fin type coolant-to air heat exchanger  119 , in order to prevent accumulation of snow and ice within and upon the HVAC intake opening  114  and HVAC intake screen  115 . The valve control line  128  may be a vacuum line, an air pressure line, or an electrical conductor. The automatically controlled valve  124  itself, then, may be pressure actuated, vacuum actuated, or electrically actuated. The automatically controlled valve  124  of the type shown in  FIG. 10  may also be used with a coolant-to-air radiant heat exchanger  130  (not shown) or a conductive heat exchanger  134  (not shown). 
     FIG. 11  shows a partial view of a vehicle  101  having an engine  102 , a chassis  103 , and a cab  104 , similar to the vehicle  101  shown in  FIG. 2 . The hood  105  of vehicle  101  is not shown in  FIG. 11 . The cab  104  of the vehicle  101  shown in  FIG. 11  is again provided with a windshield  106 , windshield wipers  107 , a cowl  108 , and a cowl tray  109 . An HVAC system  113  connects to the cowl tray  109 , passes through the cowl  108 , and into the interior of the cab  104 , in order to provide heated or cooled air to the occupants thereof. Air enters the HVAC system  113  at the HVAC intake opening  114 , which is integrated into the cowl tray  109 . An embodiment of the present invention, a tube-and-fin type coolant-to-air heat exchanger  119  is located within the HVAC intake opening  114 , proximate to the HVAC intake opening  114 . The HVAC intake screen  115 , which protects the HVAC intake opening  114  against the entry of large debris, is not shown, so that the tube-and-fin type coolant-to-air heat exchanger  119  may be shown more clearly. Additional tube-and-fin type coolant-to-air heat exchangers  119  are attached to the cowl tray  109  along its length, proximate to the base of the windshield  106 . For the sake of illustration, tube-and-fin type coolant-to-air heat exchangers  119  are shown in  FIG. 11 , although the coolant-to-air heat exchangers may also be coolant-to-air radiant heat exchangers  130  as in  FIG. 5 , conductive heat exchangers  134  as in  FIG. 6 , or a combination of tube-and-fin type coolant-to-air heat exchangers  119 , coolant-to-air radiant heat exchangers  130 , and conductive heat exchangers  134 , as the object of  FIG. 11  is to illustrate the use of multiple coolant-to-air heat exchangers within the HVAC intake opening  114  and attached to the cowl tray  109  along its length. Coolant lines  120  carry heated engine coolant from the engine  102  to the tube-and-fin type coolant-to-air heat exchangers  119 . A manual underhood control valve  122  is shown in  FIG. 11  controlling the availability of heated coolant to the tube-and-fin type coolant-to-air heat exchangers  119 , although a remotely controlled valve  123  as in  FIG. 9 , or an automatically controlled valve  124  as in  FIG. 10  may be used. 
   Other permutations of the invention are possible without departing from the teachings disclosed herein, provided that the function of the invention is to use a coolant to air heat exchanger to prevent accumulation of snow and ice in and upon an HVAC intake located externally to a vehicle in a location prone to snow and ice accumulation. Other advantages to a vehicle equipped with a coolant to air heat exchanger within an HVAC intake located externally to a vehicle may also be inherent in the invention, without having been described above.