Abstract:
The present invention relates to a system for delivering temperature and flow rate controlled warmed air to outlets for use in various apparatus. The system is typically in residential structures, such as homes, but could easily be adapted for apartment buildings as well as commercial buildings.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   This application is related to and claims priority from U.S. Provisional Patent Application Ser. No. 60/524,800, entitled: AIR DELIVERY SYSTEM, filed Nov. 25, 2003. U.S. Provisional Patent Application Ser. No. 60/524,800 is incorporated by reference herein. 

   FIELD OF THE INVENTION 
   The present invention is directed to systems and methods for delivering warmed air to various points in a structure at various temperatures and flow rates. 
   BACKGROUND OF THE INVENTION 
   Residential construction in the U.S. is continuing at a record pace, with over one million new homes built in the U.S. in 2003. This robust growth in new housing is expected to continue beyond 2004. 
   With the growth of the home building industry, comes growth in segments of the industry, such as upscale homes. These homes typically have central heating and air conditioning systems, and in many of these homes, a central vacuum system. These homes also include numerous upgrades, such as whirlpools, saunas, steam rooms, professional kitchens, and the like. Additional systems are constantly being sought to increase the homeowner&#39;s comfort and enjoyment of their residential unit. 
   SUMMARY OF THE INVENTION 
   The present invention relates to a system for delivering temperature and flow rate controlled warmed air to outlets for use in various apparatus. The system is typically a central system in residential structures, such as homes, but could easily be adapted for apartment buildings as well as commercial buildings. 
   An embodiment of the invention is directed to a system for delivering warmed air in a structure, for example, a house. The system includes a unit for producing and driving warmed air from the unit, and at least one port, typically multiple ports, for receiving the warmed air. The ports are such that they can be coupled with an apparatus that receives the warmed air. There is also at least one conduit, typically multiple conduits, coupled to the warmed air producing unit and the ports, the at least one conduit provides for the transport of warmed air, from the unit to the at least one port. 
   Another embodiment of the invention is also directed to a system for delivering warmed air in a structure. The system includes a unit for blowing and tempering air at adjustable flow rates and temperatures and at least one port, typically multiple ports, for receiving the blown and tempered air, the at least one port such that it supplies the blown and tempered air to an apparatus that utilizes the blown and tempered air. There is also at least one conduit, coupled with the air blowing and tempering unit and the at least one port. The at least one conduit functions to provide a pathway for the blown and tempered air from the air blowing and tempering unit to the at least one port. 
   Another embodiment of the invention is directed to an air delivery system. The system includes a unit for producing tempered air and driving the tempered air out of the unit. There is also at least one outlet, and typically multiple outlets, and at least one conduit coupled with the air tempering and driving unit and the at least one outlet. A controller functions to control the air tempering and driving unit. The controller is such that it is electronically linked to at least one control device for signaling the controller to control the air tempering and driving unit, such that air is delivered to the at least one outlet, at a temperature and a flow rate corresponding approximately to the air temperature and flow rate designated at the at least one control device. The at least one control device may be, for example, a fixed control panel or a remote controller, and is such that it is used to control air temperature and flow rates to one or more outlets. 
   Another embodiment of the invention is directed to a method for delivering air to a remote location. The method includes heating air to at least a predetermined temperature, and driving the heated air to at least one port at a predetermined flow rate. The at least one port is such that it can be coupled with an apparatus that receives the heated air at least at approximately the predetermined flow rate and approximately the predetermined temperature. The at least one port is typically proximate to the remote location and may be the remote location. The apparatus utilizes the heated and controlled flow rate air for one or more functions. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     Attention is now directed to the drawing figures, where corresponding or like numerals indicate corresponding or like components. In the drawings: 
       FIG. 1  is a diagram of a house employing an exemplary system in accordance with an embodiment of the invention; 
       FIG. 2  is a detailed view of an outlet in a room of the house of  FIG. 1 ; 
       FIG. 3  is a top view of the outlet of  FIG. 2 ; 
       FIG. 4  is a front view of the outlet of  FIG. 2 ; 
       FIGS. 5 and 6  are side views of the air warming and blowing unit in accordance with an embodiment of the invention; 
       FIG. 7  is a top view of the air warming and blowing unit of  FIGS. 5 and 6 ; 
       FIG. 8  is a perspective view of a remote controller in accordance with an embodiment of the invention; and 
       FIG. 9  is a perspective view of a master remote controller in accordance with an embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   The present invention relates to a system for air delivery to remote locations in a structure, such as a house or the like. The air delivery system is centralized, and provides warmed air to various outlets in the house from an air warming and blowing unit. Structures, alone or that serve as supply lines to apparatus that utilize the warmed air, can be placed into the outlets to receive the warmed air for various functions. The temperature of the warmed air and flow rate in cubic feet per minute (CFM) of the warmed air is adjustable and can be controlled for each outlet, either with a remote controller or fixed control panel for each individual outlet, or from a master (fixed) control panel, or master remote controller, through which air delivery through all of the outlets (to apparatus) may be individually controlled. The system includes a central warm air source controlled by a control system (controller), for example, computer control, processor (microprocessor) control, and related control circuitry, or other similar control. The control system is electronically linked to fixed control panels or remote controllers. 
     FIG. 1  shows a house  20 , showing the air delivery system  22  of the invention in an exemplary operation. The air delivery system  22  is preferably designed to deliver warmed air, for example, at temperatures of approximately 90° Fahrenheit (F) to 170° F., with adjustibility of approximately ±10° F. The warmed air is delivered from an air warming and blowing unit  23  to various outlets  24   a – 24   o , located in various rooms  29 – 38  of the house  20 . The rooms  29 – 38  have walls, indicated by the room number with a “w”, floors, indicated by a room number with an “f”, and ceilings, indicated by a room number with a “c”. For example, the laundry room  32 , has walls  32   w , a floor  32   f  and a ceiling  32   c . Walls in rooms not shown, for example, the door of the garage is not shown, so the walls w behind the garage door, are indicated as “w”. 
   The system  22  includes an air warming and blowing unit  23  that provides warmed air to the outlets  24   a – 24   o  through a series of connected conduits  48   a – 48   e . The air travels from the air warming and blowing unit  23 , through the conduits  48   a – 48   e , to the outlets  24   a – 24   o , in the direction of the arrows  49 . 
   At each outlet  24   a – 24   o , the air warming and blowing unit  23  can be controlled, such that the warmed air is temperature controlled and the air flow rate is controlled (adjustable) for each outlet. Control of the air temperature and air flow rate from the air warming and blowing unit  23  is through one or more of, remote controllers  50  (only one shown) for one or more specific outlets, fixed control panels, for one or more specific outlets, such as fixed control panels  52   a ,  52   b , one or more master control panels, such as the single master control panel (master controller)  54 , or a master remote controller  56  (similar to the master control panel  54 , but in the form of a remote controller). The remote controllers  50 , fixed control panels  52   a ,  52   b , master control panel  54  and master remote controller  56  are collectively referred to herein as “control devices.” 
   All of the aforementioned control devices are electronically linked, by wired or wireless links, or combinations thereof, to the controller  152  (detailed below), that controls the air warming and blowing unit  23 , detailed below. Direct electronic links between any of the control devices and the components of the air warming and blowing unit  23  are also permissible. 
   Additionally, while various outlets  24   a – 24   o  are shown as controlled by various control devices, this is exemplary only, as any of the outlets  24   a – 24   o  may be controlled by one or more of the aforementioned control devices. The control devices are all programmable, such that the user can select the outlets, that are to be controlled by the desired control device or control devices. 
   The control devices can also be configured such that if two outlets are potentially controllable by two control devices, a hierarchy among the control devices can be established. For example, the master control panel  54  or master remote controller  56 , typically has hierarchy over remote controllers, such as the remote controller  50  or the fixed control panels  52   a ,  52   b . The control devices can interface with computer type devices and other processor controlled devices, so as to be programmable over cellular networks, wide area networks, such as the Internet or local area networks (LANs). 
   The remote controllers, such as remote controller  50 , and the fixed control panels, such as fixed control panels  52   a  and  52   b , are typically specific to one, but in some cases is specific to two or more outlets, for example, when a single apparatus draws from two or more outlets, or for controlling grouped outlets supporting different apparatus. This remote controller  50  is detailed in  FIG. 8 , described below. Fixed control panels  52   a ,  52   b  are similar in all aspects to the remote controllers, but may employ both wired and/or wireless links for controlling air temperature and air flow rate from the air warming and blowing unit  23 . 
   The master control panel (master controller)  54  is typically affixed to a wall in a centralized location in the house, for example, a basement utility room  29  or a utility room  30  as shown. Through the master control panel  54 , the air temperature and flow rate can be controlled for all of the individual outlets  24   a – 24   o , or a master remote controller  56 , that functions similar to that of the master control panel  54 , but is a remote controller, and is shown in  FIG. 9  below. 
   The outlets  24   a – 24   o , are shown, for example, in use with various apparatus (devices) in various rooms of the house  20 . The air warming and blowing unit  23  is typically located in the basement  31  of the house, where the furnace unit is typically located. A conduit  48   a  extends from this air warming and blowing unit  23 , and branches into conduits  48   b  and  48   c . Conduit  48   d , extends from conduit  48   c , and conduit  48   e  extends from conduit  48   d . The aforementioned conduits  48   a – 48   d  allow for the transport of the warmed air form the air warming and blowing unit  23  to the respective outlets  24   a – 24   o  (in the direction of the arrows  49 ). 
   Outlets  24   a  and  24   b , located in the laundry room  32 , receive warmed air through the conduit  48   b . These outlets  24   a  and  24   b  are shown supporting a shoe dryer or shoe warmer  60 , that connects (attaches) directly to the outlets  24   a ,  24   b , as the apparatus, the shoe warmer  60 , includes tubular structures for receipt in the outlets  24   a ,  24   b . Alternately, the shoe dryer or shoe warmer  60 , as well as other apparatus described herein, that are “directly connected” to their respective outlet(s), can be connected through connector hoses, detailed below. Also in this room  32 , outlet  24   c , that receives warmed air from the conduit  48   d , connects, typically by a line  62 , to a drying/warming closet  64 . 
   Outlet  24   d , located in the garage  33 , receives warmed air through the conduit  48   b . This outlet  24   d  supports a line  66 , that is used to warm the interior of an automobile  68 . The line  66 , or a different line (when connected to the outlet  24   d ), can be used as a pet bed warmer, refrigerator/freezer defroster, pipe warmer/defroster for frozen pipes, and, if of sufficient length, can be used outside of the garage  33  to melt snow, ice and the like. Also in the garage  33 , outlets  24   e  and  24   f , receive warmed air through the conduit  48   c , and a room warmer  70  connects (attaches) directly to these outlets  24   e ,  24   f.    
   Outlets  24   g ,  24   h , located in the kitchen  33 , receive warmed air through the conduit  48   c . Outlet  24   g , supports a line  72 , that connects to a food warmer  74 , while outlet  24   h , supports a line  76 , that connects directly into the outlet  24   h  and extends inside a dish warmer and dryer  78 . Conduit  48   c  terminates at outlet  24   i , in a closet  35 , that has a clothes warmer  80 , that connects to the outlet  24   i , through a line  82 . 
   Conduit  48   d , extends from conduit  48   c , and supports the outlet  24   j  in the bedroom  36 . The outlet  24   j , supports a line  84 , that connects directly into the outlet  24   j  and is placed under the bed  86  to server as a bed warmer. Also in the bedroom  36  is an outlet  24   k , from the conduit  48   e  (that extends from conduit  48   d ), that attaches to a line  88  for a hair dryer  90  or other similar appliance. The hair dryer  90 , can be such that it sits on a dressing table or vanity  91 . The hair dryer  90 , for example, may be controlled by the remote controller  50 , exemplary of remote controllers suitable for controlling any of the outlets (here, for example, single or paired depending on the apparatus being supported) described herein. 
   Conduit  48   d  supports the outlets  24   l  and  24   m , in the master bedroom bathroom  37 . A tub/shower floor warming unit  94  attaches directly to the outlet  24   l , for warming a tub/shower  95 . A towel warming rack  96  attaches directly to the outlet  24   m , for warming towels  97  and the like. Outlet  24   n , that receives warmed air from conduit  48   e , connects to a line  88   a  for a hair dryer  90   a , or other similar appliance. The hair dryer  90   a  may be a wall mounted hair dryer. The hair dryer  90   a , for example, may be controlled by a fixed control panel  52   a , exemplary of fixed controllers suitable for controlling one or more outlets (here, for example, single, paired or otherwise grouped, depending on the apparatus being supported) described herein. 
   While outlets  24   a – 24   o  are shown throughout the house  20 , any number of outlets in any number of rooms, including the attic  38 , controllable by any of the control devices detailed above, is also permissible. Additionally, the master control panel  54  can be linked to a network, such as the Internet or a local area network (LAN), as well as a cellular network, to be controlled by computers, on site or remote, or by a cellular telephone or other device capable of accessing the cellular network, the Internet, or the LAN. The master control panel  54  can also be such that it is linked (electronically) and coordinated with other house functionalities, such as alarm systems, electrical system controllers, and the like. 
   Conduit  48   d  terminates in one or more external outlets  24   o  (only one shown), at locations on the exterior of the house  20 . For example, lines (not shown) may be connected to the outlet(s)  24   o  to bring warmed air to desired locations, for applications such as ice and snow melting. The external outlet(s)  24   o , are shown, for example, as controlled by the fixed control panel  52   b.    
   As stated above, the conduits  48   a – 48   d  are all interconnected and they are, for example, within the areas between the walls, floors and ceilings, under the floors or above the ceilings. The conduits  48   a – 48   e  are of piping suitable for carrying warmed air. For example, the majority of the piping may be approximately three inches (approximately 7.6 cm) in diameter with piping extending between the walls of the closet  35  and the bedroom  36 , the bedroom  36  and the bathroom  37 , and the utility room  30  and the garage  33 , may be approximately two inches (approximately 5.1 cm) in diameter. This piping may be, for example, Chlorinated Poly (Vinyl Chloride) (CPVC) or galvanized metal piping, able to withstand temperatures up to approximately 210° Fahrenheit (approximately 98.9° Celsius). The piping is such that pipes that form it, and accordingly, the conduits  48   a – 48   e , are joined together by conventional pipe fitting and joining techniques, including the use of expansion joints where necessary (depending on the particular structure). 
   The piping is typically insulated on its outside. Insulation may be, for example, polyethylene foam, approximately two inches (approximately 5.1 cm) thick, that “snaps on” to the respective pipes. 
   Turning also to  FIGS. 2–4 , an outlet  24   k , exemplary of all of the outlets  24   a – 24   o , is now shown in detail. The outlet  24   k  includes a box  110 , that terminates in a rim  112 , for example, forming a port  113 , for example, a circular shaped opening  114 , configured to receive a correspondingly shaped ring  115  on a line, for example, line  88 , formed of a hose or the like, for connecting to an apparatus (hair dryer  90  in the bedroom  36 ), as detailed above, or portion of an apparatus (as detailed above) in a frictional engagement. Alternately, the connection may be a mechanical locking connection, either alone or coupled with the frictional engagement. There may also be a mechanism in the rim  112 , that when moved, for example, when the ring  115  of the hose  88  is received therein, activates a switch (not shown), for example, a low voltage switch, that activates the air warming and blowing unit  23  (either directly or through the controller  152 ), as detailed below. Other connections between the rim  112  and the ring  115  are suitable, provided the ring  115  will remain at least temporarily retained in the rim  112 . 
   The box  110  receives an elbow tube  118  that couples the rim  112  with the conduit for delivering the warmed air, for example, the conduit  48   e . The box  110  is anchored in the walls, for example walls  36   w  and  37   w , by conventional fastening devices or systems. A cover  120  extends from the front of the box  110 , and is hingedly attached to the box  110 , by spring-biased hinges  122  (only one shown). The hinges  122  are spring biased, such that the cover  120  is normally in a closed position, covering the opening  114  of the rim  112 . 
   When operation is desired, the cover  120  is lifted and the line  88  (or other tubular structure) is attached such that the ring  115  of the line  88  frictionally engages the rim  112  if the box  110 . This engagement may also be a locking engagement (for example, a mechanical engagement). 
   The control device, for example, the remote controller  50 , controlling the outlet, here, outlet  24   k , may now be used to control the air temperature and air flow rate from the air warming and blowing unit  23 . The cover  120 , now in the open position, rests on the line  88 , as shown in  FIG. 2 . Air flows through elbow tube  118  and out of the port  113  into the requisite line, for example, line  88 , or other tubular carrier in the direction of the arrows  49 ′. 
   Alternately, the engagement of the ring  115  in the rim  112  may activate the low voltage switch (not shown), that will activate the air warming and blowing unit  23 . The now activated air warming and blowing unit  23  will have the air temperature and air flow rate from it controlled by the control device for the particular outlet. 
   Still alternately, the engagement of the ring  115  in the rim  112  may activate the low voltage switch, that will activate the air warming and blowing unit  23 . The air warming and blowing unit  23  delivers warmed air at a preset temperature and preset flow rate for the particular outlet. This can be either through a default setting or programmed into the controller  152  by the user, through any of the control devices. 
   The outlet  24   k , as well as all other outlets  24   a – 24   j  and  24   l – 24   o , typically include sensors (not shown), such as frictional (spring biased), light, or the like to detect whether the outlet is open or closed (the cover  120  is lifted or in an “up” position, or closed over the outlet opening in a “down” position). These sensors are typically electronically linked (wired, wireless or combinations thereof) to a control device, for example, the master remote controller  56 , as detailed below, on which the open status for each of the outlets is typically indicated by an active light  222 , for example, an illuminated light emitting diode (LED) ( FIG. 9 ), detailed below. These sensors can also be connected to one or more switches, for example, low voltage switch(es), that function similarly to the switch (low voltage switch) for the frictional connection between the ring  115  and the rim  112 , for activating the air warming and blowing unit  23 , as detailed above. 
   Hoses are typically used in directly connecting various apparatus, detailed above, to the respective outlets. Similarly, hoses can be used to form the transport lines, over which the warmed air is transported, such as lines  62 ,  66 ,  82 ,  84 ,  88 , and  88   a . For example, hoses for connecting the respective apparatus to outlets, such as for the “direct connections” detailed above, may be 1.25 inch internal diameter hoses of thermoplastic rubber, such as medium weight Santoprene® thermoplastic rubber, reinforced with a spring steel wire helix rated to 275° F. These connector hoses are, for example, not more than approximately six feet (1.8 m) in length. Hoses used in the transport lines, such as lines  62 ,  66 ,  82 ,  84 ,  88 , and  88   a , for example, may be constructed similarly. 
   Turning also to  FIGS. 5–7 , there is detailed the air warming and blowing unit  23 . This unit  23  includes a cabinet  140 , that houses the components that produce and drive the warmed air, to deliver it to the desired outlet  24   a – 24   o  (at the desired temperature and flow rates). The components include a blower motor unit  142 , having a motor and a fan (blower), whose air intake (where ambient air is taken into the blower motor unit  142 ) is coupled to an air filter unit  144 , and blows air through an output duct  145  into a duct hose  146 . The duct hose  146  is received by a heating element  148 , whose neck  150  is coupled to the conduit  48   a  ( FIG. 1 ). 
   The unit  23  also includes a controller  152 , that is typically processor based (including one or more microprocessors, for example, Pentium® microprocessors, capable of running software programs). The controller  152 , typically also includes control circuitry. 
   The controller  152  controls the blower motor unit  142  and the heating element  148 , to produce the requisite warmed air for delivery to the requisite outlet  24   a – 24   o , at the desired temperature and the desired flow rate. The controller  152  is electronically linked, by wired, wireless, or combinations of wired or wireless links, or combinations thereof, to the aforementioned control devices, to control air delivery, flow rate and temperature, to the outlets controlled by the specific control device or devices. The controller  152  can also perform timed shut off at the outlets  24   a – 24   o.    
   The controller  152  is also electronically linked (by links that are wired, wireless or combinations thereof) to sensors (not shown) in the air warming and blowing unit  23 , that detect air flow irregularities and clogged filters in the air warming and blowing unit  23 . These sensors are monitored by the controller  152 , that sends signals to the blower motor unit  142  (the blower motor) to shut down if a clog or other irregularity in the airflow is detected. 
   The cabinet  140  is typically made of stainless steel or the like, and is, for example, approximately 36 inches (approximately 91 cm) tall. The filter unit  144  includes at least one filter, similar to that found in residential furnace units. The filter unit  144  may be placed anywhere in the air flow path in or external to the cabinet  140 . 
   The blower motor unit  142  includes a motor, that is, for example, a three speed motor, that coupled with the fan, produces output air flows (flow rates) ranging from approximately 40 to 80 cubic feet per minute (CFM), through a 2.047 inch (5.199 cm) internal diameter output duct. The blower motor unit  142  is such that it includes a pressure switch (not shown) that will shut down the blower motor unit  142  if all of the outlets  24   a – 24   o  are closed. Each outlet  24   a – 24   o , typically has a sensor for detecting whether the outlet is open or closed and for reporting this condition to the controller  152 , as detailed above. The controller  152  controls the pressure switch, based on the open/closed status of the outlet. 
   The heating element  148  provides tempered, typically warmed (heated) air, typically to approximately 180° F., with a preferred range for the heated air being approximately 90° F. to approximately 170° F. and approximately ±10° F. The blower motor unit  142  typically also includes an over temperature switch (not shown), either directly coupled to the heating element  148 , or coupled to the heating element  148  through the controller  152 . Power to the heating element  148  is deactivated when the temperature in the blower motor unit  142  reaches a predetermined threshold. This predetermined threshold may be, for example, at least 190° F. 
   As stated above, the controller  152  is electronically coupled to the blower motor unit  142  and the heating element  148 . The controller  152  is also linked wirelessly to the remote controllers, such as the remote controller  50  or a master remote controller  56  ( FIG. 9 ), and linked wired and/or wirelessly to fixed panel controllers, such as control panels  52   a ,  52   b  and master control panel  54 . The controller  152  can run programs and perform functions for the air warming and blowing unit  23 , in software, hardware or combinations thereof. 
     FIG. 8  shows an exemplary remote controller, for example, the remote controller  50 , electronically linked (wireless) to the controller  152 . This remote controller  50  includes a key panel  202 , with numerals and letters on each key, like those on a standard push button telephone, a screen  204 , an ON/OFF buttons  206   a ,  206   b , fan speed control buttons  208   a  (increase)  208   b  (decrease) and temperature control buttons  210   a  (increase)  210   b  (decrease). The screen  204  also includes sections for ON/OFF Status of the outlet  206   c  (air flowing through the outlet as controlled by the remote controller  50 ), fan speed  208   c , and air temperature  210   c . The fixed control panel, for example, control panels  52   a ,  52   b , for controlling a single outlet, are similar to the remote controller  50 , but may be wired to the controller  152 . 
   Master control panel  54  is similar to the remote controller  50  of  FIG. 8 , but includes additional features, such as a buttons to activate specific outlets, master shut offs for components of the warm air blowing unit  23 , interfaces with Transmission Control Protocol/Internet Protocol (TCP/IP) and other telephone, cable and network connections. As stated above, the master controller  54  is also electronically linked to the controller  152  by wired or wireless links, or combinations thereof. The screen is also such that the specific outlet or outlets being controlled appear on screen and there may be buttons or screen indicators, for example, LEDs, for the status (open-LED active or closed-LED inactive) of each individual outlet. 
   A master remote controller  56 , as shown in  FIG. 9 , is similar to the remote controller  50 , but includes the features of the master controller  54 , including a screen position  220  for outlet number(s) being controlled at the present time, and lights (LEDs) or other visible indicia  222 , indicating outlet status (open/closed). The master remote controller  56  is wirelessly linked to the controller  152 , as well as wirelessly linked to networks, cellular, local and wide area networks, including the Internet. The remote controllers  50 ,  56  are typically battery powered and, for example, can measure approximately 2.5 inches (6.4 cm) by approximately 5 inches (12.7 cm) by approximately 0.75 inches (1.9 cm) deep, so as to be hand-held. 
   The above described air delivery system is exemplary only. As described above, the system  22  is particularly suitable for a 3000–8000 square foot house (residence) that is preferably new construction. While numerous outlets  24   a – 24   k  are shown, these are exemplary of the various outlets and apparatus that can be supported by the system  22 . For example, the system  22  is such that it supports approximately ten outlets in the aforementioned house, with, for example, a maximum of two outlets open and being delivered air at any single time, and with the outlets preferably being not more than approximately 60 feet (approximately 18.3 meters) from the air warming and blowing unit  23 , as through the respective conduits  48   a – 48   e.    
   Alternately, the system  22  may be configured for blowing ambient temperature or cooled air. Still alternately, the air warming and blowing unit  23 , although shown as a single unit, can be divided into two or more separate units. 
   While preferred embodiments of the present invention have been described, so as to enable one of skill in the art to practice the present invention, the preceding description is intended to be exemplary only. It should not be used to limit the scope of the invention, which should be determined by reference to the following claims.