Abstract:
A fireplace configured for reducing the heating, and hence the temperature, of the surface above the front face of the fireplace. The fireplace includes an air management system for separating one or more relatively warm air stream from one or more relatively cool air stream. The relatively cooler air stream exiting the fireplace may be drawn by the relatively warmer air exiting the fireplace into flowing upwards along a surface above the front face of the fireplace. An insulating layer of relatively cooler air may form between said surface and the relatively warmer air exiting the fireplace.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates to a fireplace. More specifically, the invention relates to a fireplace used for heating the conditioned space wherein it is located. In particular, the invention pertains to a fireplace design for reducing the temperature of a surface above the front face of the fireplace.  
       BACKGROUND  
       [0002]     Fireplaces have typically been used for decorative purposes, heating a conditioned space, or both. Most fireplaces, and in particular the ones used for heating, typically include a combustion chamber enclosure positioned within and space apart from an outer enclosure. Such configurations inherently include an air space between the combustion chamber enclosure and the outer enclosure. The space between the combustion chamber enclosure and the outer enclosure further provides openings at the top and bottom of the front face of the fireplace. Air may enter and/or exit the air space through these top and bottom openings.  
         [0003]     In one instance, air may be drawn into the air space through the bottom opening and exit the air space through the top opening. Air entering the air space may be from one or more sources and/or a combination of sources. For instance, air entering the air space may be from the conditioned space wherein the fireplace is located, and/or it may be from a source outside the conditioned space wherein the fireplace is located such as from outdoors. Air entering the air space may be drawn in by natural convection or by forced convection such as with an air blower.  
         [0004]     When the fireplace is in operation, relatively cooler air is drawn into the air space wherein it gets heated by the heat of combustion transferred through the combustion chamber enclosure, and the heated air exits the air space through the top opening. The relatively warmer air may flow up along the surface, such as a wall, above the top opening in the front face of the fireplace. The warm air heats the surface, and in some instances, depending upon the intensity of the combustion process, the surface may become untouchable by having been heated to a relatively high temperature. To one skilled in the art, it will be obvious that the surface above the fireplace will most likely be the hottest in instances when natural convection drives the flow of air through the air space.  
         [0005]     Accordingly, there is a need in the art for a fireplace designed to reduce the heating of the surface above the front face of the fireplace, and thereby reduce the temperature of the surface.  
       SUMMARY  
       [0006]     The instant invention provides a fireplace designed to reduce the heating, and hence reduce the temperature, of a surface above the front face of the fireplace.  
         [0007]     In one embodiment of the present invention, a flow divider placed in the air space at the top of the fireplace, i.e., in the air space between the top surface of the combustion chamber enclosure and the top surface of the outer enclosure, may define two distinctly separate air flow paths. The flow divider may further define two separate ports for the air exiting the top opening. A relatively cooler air stream may flow through a first flow path defined between the top wall of the outer enclosure and the flow divider, and exit through a first port in the top opening; and a relatively warmer air stream may flow through a second flow path defined between the flow divider and the top wall of the combustion chamber enclosure, and exit through a second port in the top opening.  
         [0008]     In an embodiment of the invention, the relatively cooler air exiting the first port may be drawn by the relatively warmer air exiting the second port into develop into an air film traversing up along the surface above the fireplace. This air film of relatively cooler air may function as an insulating layer separating the surface above the fireplace from the relatively warmer air exiting the second port.  
         [0009]     In one embodiment of the present invention, air entering the first flow path may be a portion of the air entering the air space between the outer enclosure and the combustion chamber enclosure, through an opening at the bottom of the front face of the fireplace. In another embodiment, air entering the flow path may be the air directly from the conditioned space wherein the fireplace is located. In a further embodiment, air entering the flow path may be from a source outside the conditioned space wherein the fireplace is located. One example of such source for air may be the outdoors.  
         [0010]     Another embodiment of the instant invention may include a continuous flow path defined by a channel along the surfaces of the outer enclosure wherein the channel may be spaced apart from the combustion chamber enclosure. In one such embodiment, the channel may traverse the depth between the front and the back of the bottom surface of the outer enclosure, continuing to traverse the height between the top and bottom of the back surface of the outer enclosure, and further continuing to traverse the depth between the front and the back of the top surface of the outer enclosure. Air from the conditioned space wherein the fireplace is located may be drawn into the flow channel along the bottom surface of the outer enclosure, and exit at the top front face of the fireplace. The relatively cooler air may be drawn by the relatively warmer air exiting from the top front face of the fireplace into develop into an air film traversing up along the surface above the fireplace. This air film of relatively cooler air may function as an insulating layer separating the surface above the fireplace from the relatively warmer air also exiting from the top front face of the fireplace.  
         [0011]     In an alternate embodiment, the flow channel may be along the back and top surfaces of the outer enclosure. In another embodiment, the flow channel may be in the top surface of the outer enclosure. In yet another embodiment, air drawn into the flow channel may be from a source of air outside the conditioned space wherein the fireplace is located. In one such instance, the source of air may be the outdoors.  
         [0012]     In one embodiment of the present invention, air may be drawn into and exit from the air space due to natural convection. In another embodiment, an air blower may be employed to induce air flow through the air space. In yet another embodiment of the present invention, air may be drawn into and exit from the air channel due to natural convection. In a further embodiment, an air blower may be employed to induce air flow through the air channel.  
         [0013]     While multiple embodiments of the instant invention are disclosed, still other embodiments may become apparent to those skilled in the art. The following detailed description shows and describes illustrative embodiments of the present invention. As will be realized, the embodiment are capable of modifications in various aspects, all without departing from the spirit and scope of the instant invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a side view of a conventional fireplace.  
         [0015]      FIG. 2  is a side view of a fireplace according to an embodiment of the present invention.  
         [0016]      FIG. 3  is a front view of an embodiment of a fireplace of the present invention.  
         [0017]      FIG. 4  is a front view of another embodiment of a fireplace of the present invention.  
         [0018]      FIG. 5  is a side view of a fireplace according to a further embodiment of the present invention.  
         [0019]      FIG. 6  is a side view of yet another embodiment of a fireplace of the present invention.  
         [0020]      FIG. 7  shows an embodiment of a flow channel associated with a fireplace of the present invention.  
         [0021]      FIG. 8  shows another embodiment of a flow channel for a fireplace of the instant invention.  
         [0022]      FIG. 9  is a side view of an embodiment of a fireplace of the present invention.  
         [0023]      FIG. 10A  illustrates an alternate embodiment of a flow divider.  
         [0024]      FIG. 10B  illustrates a further embodiment of a flow divider.  
         [0025]      FIG. 11  is a plan view showing an embodiment of a flow divider.  
         [0026]      FIG. 12  is a front view of another embodiment of a fireplace comprising more than one flow divider.  
         [0027]      FIG. 13  is a front view of yet another embodiment of a fireplace comprising more than one flow divider. 
     
    
     DETAILED DESCRIPTION  
       [0028]     A conventional fireplace  10 , shown in  FIG. 1 , may include combustion chamber enclosure  14  positioned within and spaced apart from outer enclosure  12 . Fireplace  10  may also include air space  16  defined by the space between enclosures  12  and  14 . Air stream  20  may be drawn into air space  16  and exit fireplace  10  as air stream  22 . Upon exiting from fireplace  10 , a portion of air stream  22  may flow upwards and along surface  24  above the front face of fireplace  10 . Entering air stream  20  and exiting air stream  22  may be induced either by natural convection or by an air blower (not shown) located within air space  16 . During operation of fireplace  10 , air stream  20  may be drawn into air space  16  wherein it may be heated by the heat of combustion transferred through the surfaces of combustion chamber enclosure  14 , and exit fireplace  10  as a relatively warm air stream  22 . The temperature of air stream  22  may be a function of the intensity of the combustion process within combustion chamber enclosure  14 . As previously stated, a portion of the relatively warm air stream  22  may flow upwards and along surface  24  above the front face of fireplace  10 , and thereby heat surface  24  causing an increase in the temperature of surface  24 . In some instances, and under certain operating conditions, the temperature of surface  24  may increase to substantially significant levels.  
         [0029]     A fireplace  50  in accordance with an embodiment of the present invention is illustrated in  FIG. 2 . As shown, fireplace  50  may include combustion chamber enclosure  14  disposed within and spaced apart from outer enclosure  12 . Fireplace  50  may also include air space  16  defined by the space between enclosures  12  and  14 . Fireplace  50  may further include flow divider  52  positioned within the space between top surface  56  of combustion chamber enclosure  14  and top surface  54  of outer enclosure  12 . Flow divider  52  may provide a first flow path  58  defined by the space between top surface  54  of outer enclosure  12  and flow divider  52 , and a second flow path  66  defined by the space between flow divider  52  and top surface  56  of combustion chamber enclosure  14 .  
         [0030]     During operation, air stream  20  may be drawn into air space  16 , heated, and divided into a first air stream  60  and a second air stream  64 . First air stream  60  may flow through first flow path  58  and exit fireplace  50  as air stream  62 . Second air stream  64  may flow through second flow path  66  wherein it may be further heated by the heat of combustion transferred through top surface  56  of combustion chamber enclosure  14 . Second air stream  64  exiting fireplace  50  as air streams  68  and  70  may be relatively warmer than air stream  62  and may draw the relatively cooler air stream  62  to flow upwards and along surface  24  above the front face of fireplace  50  and function as an insulating layer of relatively cooler air separating surface  24  from the relatively warmer air stream  70  which may also be flowing in a generally upward direction. The relative temperatures of the air streams exiting fireplace  50  may dictate the flow dynamics at the exit. In one embodiment of the present invention, the air streams may mix upon exiting fireplace  50 . One skilled in the art will appreciate that the temperature of surface  24  associated with fireplace  50  may be less than the temperature of surface  24  associated with fireplace  10 .  
         [0031]     In an embodiment of the present invention, flow divider  52  may include a heat insulating material for minimizing heat transfer between flow paths  58  and  66 . In an alternate embodiment, flow divider  52  itself may be formed from a heat insulating material.  
         [0032]      FIG. 3  is a front view of an embodiment of a fireplace such as fireplace  50  illustrated in  FIG. 2 . As shown in  FIG. 3 , flow divider  52  may span the entire width of the opening between top surfaces  54  and  56 . In one such instance, first air stream  60  may exit first flow path  58  across a substantial width of the opening between top surface  54  and flow divider  52 . Similarly second air stream  64  may exit second flow path  66  across a substantial width of the opening between flow divider  52  and top surface  56 .  
         [0033]      FIG. 4  is a front view of another embodiment of a fireplace wherein flow divider  80  may not span the entire width of the opening between top surfaces  54  and  56 . As shown, flow divider  80  may span a portion of the width of the fireplace, and provide for a first flow path  82  defined between a portion of top surface  54  and flow divider  80 . The remainder of the opening between top surfaces  54  and  56  may define a second flow path  84 . In one embodiment, flow divider  80  may be centered proximate the center of the front width of top surface  54 . In one such instance, relatively cooler first air stream  60  may exit first flow path  82  across a portion of the width of top surface  54  while relatively warmer second air stream  64  may exit second flow path  84  across a substantial width of the opening between top surfaces  54  and  56 . The relatively cooler air stream exiting first flow path  82  may be drawn by the relatively warmer air exiting the second port into flowing upwards and along surface  24  above the front face of fireplace  50  and function as an insulating layer of relatively cooler air separating surface  24  from the relatively warmer air stream exiting second flow path  84 . The relative temperatures of the air streams exiting fireplace  50  may dictate the flow dynamics at the exit. In one embodiment of the present invention, the air streams may mix upon exiting fireplace  50 .  
         [0034]     In accordance with another embodiment of the present invention, a side view of fireplace  90  is illustrated in  FIG. 5 . Fireplace  90  may include combustion chamber enclosure  14  disposed within and spaced apart from outer enclosure  92 . Fireplace  90  may also include air space  16  defined by the space between enclosures  92  and  14 . Fireplace  90  may further include flow divider  94  positioned within the space between top surface  56  of combustion chamber enclosure  14  and top surface  108  of outer enclosure  92 . As shown, flow divider  94  may extend to the rear surface of outer enclosure  92 . Flow divider  94  may provide a first flow path  96  defined by the space between top surface  108  of outer enclosure  92  and flow divider  94 , and a second flow path  112  defined by the space between flow divider  94  and top surface  56  of combustion chamber enclosure  14 . Outer enclosure  92 , as shown, may include port  98  through which air stream  100  may enter first flow path  96 .  
         [0035]     In one embodiment of the present invention, port  98  may include a flow damper  110  for regulating the flow of air stream  100 . Damper  110  may be one of several different designs and operational characteristics as is well known in the art. In one instance, damper  110  may be a motorized damper. In another instance, damper  110  may be gravity operated such that port  98  may be closed when damper  110  is in its normal position, and port  98  may be opened when inducement by a draft of air stream  100 .  
         [0036]     During operation, air stream  100  may be drawn into first flow path  96  and exit fireplace  90  as air stream  102 . Also, air stream  20  may be drawn into air space  16 , heated, flow through second flow path  112  wherein it may be further heated by the heat of combustion transferred through top surface  56  of combustion chamber enclosure  14 , and then exit fireplace  90  as air streams  104  and  106 . In one such embodiment, air streams  104  and  106  may be relatively warmer than air stream  102  and may draw the relatively cooler air stream  102  into flowing upwards and along surface  24  above the front face of fireplace  90  and function as an insulating layer of relatively cooler air separating surface  24  from the relatively warmer air stream  106  which may also be flowing in a generally upward direction. The relative temperatures of the air streams exiting fireplace  90  may dictate the flow dynamics at the exit. In one embodiment of the present invention, the air streams may mix upon exiting fireplace  90 .  
         [0037]     Air stream  100  entering first flow path  96  may be drawn from one or more sources of air, either singularly or in combination. In one embodiment, the source of air stream  100  may be the conditioned space wherein the fireplace is located. In another embodiment, air stream  100  may be from a source of air other than the conditioned space wherein the fireplace is located. An example of one such source of air may be the outdoors. Another example of such source of air may be the fireplace chase. Alternately, the source of air may be a conditioned space other than the conditioned space wherein the fireplace is located. In a further embodiment, the source of air may be an unconditioned space. In some instance, the source of air may be a space such as a basement of the structure wherein the fireplace is located. In an alternate embodiment, air stream  100  may be a combination of air from more than one source. An example of one such combination may be the outdoor and the conditioned space wherein the fireplace is located.  
         [0038]     In yet another embodiment of the present invention, such as that shown in  FIG. 6 , fireplace  120  may include combustion chamber enclosure  14  disposed within and spaced apart from outer enclosure  122 . Fireplace  120  may also include flow channel  126  spaced apart from combustion chamber enclosure  14 , and defined as the space between the surfaces of outer enclosure  122  and the surfaces of flow channel enclosure  124 .  
         [0039]     As illustrated in  FIG. 7 , flow channel  126  may span a portion of the width of the surfaces of outer enclosure  122 . In one such instance, fireplace  120  of  FIG. 6  may include air space  130  defined by the space between the surfaces of combustion chamber enclosure  14  and the surfaces of outer enclosure  122 , not occupied by flow channel  126 . In alternative embodiments of the present invention, a flow channel such as flow channel  126  of  FIG. 7  may be formed at any location on the surfaces of outer enclosure  122 . For instance, flow channel  126  may be formed along one or more corners of outer enclosure  122 . Alternately, flow channel  126  may be formed along a center portion of the surfaces of outer enclosure  122 . Several other arrangements are possible, and all such embodiments are considered as falling within the scope of the instant invention.  
         [0040]     In a further embodiment shown in  FIG. 8 , flow channel  140  may traverse across the entire surfaces of outer enclosure  122 , and spaced apart from combustion chamber enclosure  14 . In one such instance, fireplace  120  of  FIG. 6  may include air space  130  defined as the space between the surfaces of combustion chamber enclosure  14  and surfaces  142  of flow channel  140 .  
         [0041]     During operation, air stream  128  may be drawn into flow channel  126  and exit fireplace  120  as air stream  128 . Also, air stream  20  may be drawn into air space  130 , heated, and exit fireplace  120  as air streams  132  and  134 . In one such embodiment, air streams  132  and  134  may be relatively warmer than air stream  128  and may draw the relatively cooler air stream  128  into flowing upwards and along surface  24  above the front face of fireplace  120  and function as an insulating layer of relatively cooler air separating surface  24  from the relatively warmer air stream  134  which may also be flowing in a generally upward direction. The relative temperatures of the air streams exiting fireplace  120  may dictate the flow dynamics at the exit. In one embodiment of the present invention, the air streams may mix upon exiting fireplace  120 .  
         [0042]     Air stream  128  entering flow channel  126  may be drawn from one or more sources of air, either singularly or in combination. In one embodiment, the source of air stream  128  may be the conditioned space wherein the fireplace is located. In another embodiment, air stream  128  may be from a source of air other than the conditioned space wherein the fireplace is located. An example of one such source of air may be the outdoors. Another example of such source of air may be the fireplace chase. Alternately, the source of air may be a conditioned space other than the conditioned space wherein the fireplace is located. In a further embodiment, the source of air may be an unconditioned space. In some instance, the source of air may be a space such as a basement of the structure wherein the fireplace is located. In an alternate embodiment, air stream  128  may be a combination of air from more than one source. An example of one such combination may be the outdoor and the conditioned space wherein the fireplace is located.  
         [0043]      FIG. 9  illustrates a further embodiment of the instant invention wherein fireplace  150  may include combustion chamber enclosure  14  disposed within and spaced apart from outer enclosure  152 . In many respects, fireplace  150  may be substantially similar to fireplace  120  of  FIG. 6 . One primary difference between fireplace  120  and fireplace  150  may be that fireplace  150  may not have a flow channel on the bottom surface of outer enclosure  152 . As shown in  FIG. 9 , flow channel  156  associated with fireplace  150  may traverse the back and top surfaces of outer enclosure  152 . Also as shown in  FIG. 9 , a portion of air stream  20  may flow through flow channel  156 . In one instance, the air stream entering flow channel  156  may be drawn from one or more sources of air, either singularly or in combination. In one embodiment, the source of air stream for flow channel  156  may be the conditioned space wherein the fireplace is located. In another embodiment, the air stream entering flow channel  156  may be from a source of air other than the conditioned space wherein the fireplace is located. An example of one such source of air may be the outdoors. In an alternate embodiment, the air stream entering flow channel  156  may be a combination of air from more than one source. An example of one such combination may be the outdoor and the conditioned space wherein the fireplace is located.  
         [0044]     During operation, an air stream may be drawn into flow channel  156  and exit fireplace  150  as air stream  158 . Also, air stream  20  may be drawn into air space  130 , heated, and exit fireplace  150  as air streams  160  and  162 . In one such embodiment, air streams  160  and  162  may be relatively warmer than air stream  158  and may draw the relatively cooler air stream  158  into flowing upwards and along surface  24  above the front face of fireplace  150  and function as an insulating layer of relatively cooler air separating surface  24  from the relatively warmer air stream  162  which may also be flowing in a generally upward direction. The relative temperatures of the air streams exiting fireplace  150  may dictate the flow dynamics at the exit. In one embodiment of the present invention, the air streams may mix upon exiting fireplace  150 . FIG. 10A  shows an alternate embodiment of flow divider  170 . Flow divider  170  may include flow diverter  172  in a generally upward direction at the front edge proximate the front face of a fireplace. The generally upward direction of flow diverter  172  may further assist flow stream  174  to flow in an upward direction. Flow divider  170  may further include flow diverter  176  in a generally downward direction at the back edge proximate the back surface of outer enclosure  12 . The embodiment of flow divider  170  shown in  FIG. 10A  may have both a front flow diverter  172  and a rear flow diverter  176 . Alternate embodiments of flow divider  170  may include only one of the two flow diverters  172  and  176 , and not both. In an embodiment of a fireplace of the present invention, flow diverter  172  may, in addition to the relative temperatures of the air streams exiting the fireplace, dictate the flow dynamics at the exit. In one embodiment of the present invention, the air streams may mix upon exiting the fireplace. One skilled in the art will appreciate the influence of such a flow diverter in the mixing of the air streams exiting the fireplace.  
         [0045]      FIG. 10B  shows a further embodiment of flow divider  180 . Flow divider  180  may include flow diverter  182  in a generally downward direction at the front edge proximate the front face of a fireplace. Top surface  54  of the fireplace may include flow diverter  184  in a generally downward direction proximate the front face of the fireplace. The generally downward directions of flow diverters  182  and  184  may direct flow stream  186  to flow in a downward direction. Flow divider  180  may further include another flow diverter in a generally downward direction, such as flow diverter  176  of  FIG. 10A , at the back edge proximate the back surface of outer enclosure  12 . The embodiment of  FIG. 10B  may include flow diverter  184  in a generally downward direction, however flow diverter  184  may alternatively have a generally upward direction. One skilled in the art will appreciate the influence of the direction of a flow diverter in the mixing of the air streams exiting the fireplace.  
         [0046]     A plan view of fireplace  300  including flow divider  190  positioned therein is illustrated in  FIG. 11 . Outer enclosure  12  of fireplace  300  may include left surface  210 , rear surface  212 , and right surface  214 . As shown, flow divider  190  may include left side  192 , left angled side  194 , rear side  196 , right angled side  198 , and right side  200 . Left flow path  202  and right flow path  204  may be provided proximate the rear of fireplace  300 . As shown, left flow path  202  may be defined by the space between left surface  210  and rear surface  212  of outer enclosure  12 , and left angled side  194  of flow divider  190 . Similarly, right flow path  204  may be defined by the space between right surface  214  and rear surface  212  of outer enclosure  12 , and right angled side  198  of flow divider  190 . In one such embodiment of a fireplace, air such as air stream  60  of fireplace  50  ( FIG. 2 ) may enter a flow path such as first flow path  58  of fireplace  50  ( FIG. 2 ) through left flow path  202  and right flow path  204 . While  FIG. 11  may imply one or more gaps between left surface  210  and left side  192 , between rear surface  212  and rear side  196 , and between right surface  214  and right side  200 , it should be understood that such one or more gaps may or may not exist in alternate embodiments of the present invention. Accordingly, left surface  210  and left side  192  may be fixedly attached to one another. Or, left surface  210  may be spaced apart from left side  192  thereby forming a flow path. Alternately, the gap may be closed by means such as a channel on the inside surface of left surface  210  wherein the channel is configured to receive left side  192 . Similar arrangements may be provided for the rear and the right side of outer enclosure  12 . Further embodiments of fireplace  300  may include only left flow path  202 , or it may include only right flow path  204 . In still further embodiments, left flow path  202  and right flow path  204  may be defined differently than the embodiment of  FIG. 11 . In one such instance, one or more flow paths may be defined along left surface  210  of outer enclosure  12 . In another instance, one or more flow paths may be defined along right surface  214  of outer enclosure  12 . In yet another instance one or more flow paths may be defined along rear surface  212  of outer enclosure  12 . In a further embodiment, fireplace  300  may include flow paths along more than just one surface of outer enclosure  12 .  
         [0047]      FIG. 12  illustrates an embodiment of a fireplace  400  including one or more flow dividers. In one such embodiment, fireplace  400  may include several flow dividers, such as flow dividers  402 ,  404 ,  406 ,  408 ,  410 ,  412  and  414 , within the space between the one or more surfaces of outer enclosure  12  and the one or more surfaces of combustion chamber enclosure  14 .  
         [0048]      FIG. 13  shows another embodiment of a fireplace  500  including one or more flow dividers. In one such embodiment, fireplace  500  may include several flow dividers, such as flow dividers  502 ,  504 ,  506 ,  508 ,  510  and  512 , within the space between the one or more surfaces of outer enclosure  12  and the one or more surfaces of combustion chamber enclosure  14 .  
         [0049]     Further embodiments of a fireplace with one or more flow dividers may be envisioned. In one such instance, the fireplace may include one or more flow dividers arranged in a manner which is all and/or part of a combination of the embodiments of  FIGS. 12 and 13 . All such embodiments are considered as being within the scope and intent of the present invention.  
         [0050]     Various modifications and additions may be made to the exemplary embodiments presented hereinabove without departing from the scope and intent of the present invention. For example, while the disclosed embodiments refer to particular features, the scope of the instant invention is considered to also include embodiments having different combinations of features that do not include all of the features described herein. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as falling within the scope and intent of the appended claims, including all equivalents thereof.