Fireplace front panel assembly for reducing temperature

A heating appliance includes an outer enclosure including a transparent front panel, a combustion chamber enclosure, and a variable speed blower. The combustion chamber enclosure is positioned within the outer enclosure and defines a combustion chamber wherein radiant heat is generated. The combustion chamber enclosure also includes a transparent front panel. The blower is configured to generate an adjustable airflow between the outer enclosure front panel and the combustion chamber enclosure front panel and to exhaust the airflow to a remote location. The airflow absorbs at least some of the radiant heat and varying a speed of the blower controls an amount of radiant heat transferred from the combustion chamber to a living space in which the heating appliance is exposed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to heat generating appliances, and more specifically relates to systems and methods of cooling exposed surfaces of a heat-generating appliance.

2. Related Art

Heating appliances such as fireplaces, stoves and fireplace inserts have become increasingly commonplace in homes, businesses, and other buildings. These and other types of heating appliances provide benefits an aesthetically pleasing arrangement of, for example, flames, sounds, and smells in addition to the generation of heat. Such heating appliances is typically mounted in a wall of a structure or directly adjacent to a wall structure and may include one or more exposed surfaces.

The exposed surfaces of the heating appliance can create safety issues. For example, because the heating appliance produces heat, it is possible for one or more of the exposed surfaces to become heated. Surfaces of a heating appliance that are typically exposed are the viewing surface or surfaces through which the interior of the fireplace is viewed and the surround which surrounds the fireplace.

The exposed surfaces may become hot and pose a risk of burns to individuals or damage to objects that come into contact with the surfaces. Current fireplace design fails to adequately provide means of maintaining the exposed surfaces of the heating appliance at a temperature that is safe.

Thus, there is a need for a system and method for cooling an exposed surface of a heating appliance.

SUMMARY OF THE INVENTION

The present invention relates to heating appliances having a reduced temperature exposed surface. One aspect of the invention relates to a heating appliance such as a fireplace, stove, or stove insert that includes an outer enclosure having a transparent front panel, a combustion chamber enclosure, and a variable speed blower. The combustion chamber enclosure is positioned within the outer enclosure and defines a combustion chamber wherein radiant heat is generated. The combustion chamber enclosure also includes a transparent front panel. The blower is configured to generate an adjustable airflow between the outer enclosure front panel and the combustion chamber enclosure front panel and to exhaust the airflow to a remote location. The airflow absorbs at least some of the radiant heat and varying a speed of the blower controls an amount of radiant heat transferred from the combustion chamber to a living space in which the heating appliance is exposed.

The heating appliance may also include an interior panel that is positioned between the front panels of the outer and combustion chamber enclosures. The interior panels defines a first air space between the interior panel and the combustion chamber enclosure front panel, and a second air space between the interior panel and the combustion chamber enclosure front panel. A first airflow passes through the first air space and a second airflow, separate from the first airflow, passes through the second air space. The first and second airflows can help reduce a temperature of the outer enclosure front panel as well as transfer radiant heat away from the heating appliance.

Another aspect of the invention relates to a method of controlling radiant heat output from a heating appliance. The heating appliance includes an outer enclosure having a transparent front panel, a combustion chamber enclosure having a transparent front panel and defining a combustion chamber, and a variable speed blower. The method includes positioning the combustion chamber enclosure within the outer enclosure, generating radiant heat in the combustion chamber enclosure, generating an airflow into and out of the outer enclosure with the blower, moving the airflow between the front panels of the outer enclosure and the combustion chamber enclosure, and varying a speed of the blower to control the amount of radiant heat transferred from the combustion chamber through the front panel of the outer enclosure.

Another method of the invention relates to a method of removing heated air from a heating appliance. The heating appliance includes an outer enclosure having a front panel, a combustion chamber enclosure having a front panel and defining a combustion chamber wherein heat is generated, an inner panel, a direct vent assembly coupled to the combustion chamber, and first and second exhaust assemblies. The method includes positioning the inner panel between the front panels of the outer enclosure and the combustion chamber enclosure, the inner panel defining first and second air chambers. The method also includes coupling the first and second exhaust assemblies to respective first and second air chambers and providing a source of fresh air to the combustion chamber and exhausting combustion gases from the combustion chamber with the direct vent assembly. The method may further include removing heated air from the first air chamber with the first vent assembly and removing heated air from the second air chamber with the second vent assembly.

A still further aspect of the invention relates to a panel assembly suited for use with a heating appliance. The panel assembly includes a pair of panels spaced apart in parallel orientation to define an air plenum, wherein one of the panels provides an exposed surface of the heating appliance and the air plenum is fluidly separated from a combustion chamber of the heating appliance and a living space in which the heating appliance is exposed. The panel assembly also includes a variable speed blower configured to remove heat from the air plenum and exhaust the removed heat to a location remote from the heating appliance.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. In particular, the example embodiments described below in relation to the Figures are the application of the present invention in a fireplace, whereas many other fields may be applicable to fulfill the purposes and intents of the present invention. Figures in the detailed description that follow more particularly exemplify certain embodiments of the invention. While certain embodiments will be illustrated and describe embodiments of the invention, the invention is not limited to use in such embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention generally relates to heating appliances, and more specifically relates to systems and methods of cooling exposed surfaces of a heating appliance and directing heat generated by the heating appliance away from the appliance. The heating appliance may include a double air wash assembly that provides at least two layers of circulating air between the exposed front panel of the appliance outer enclosure and the front panel of a combustion chamber enclosure positioned within the outer enclosure. These layers of air may be heated by heat generated in the combustion chamber. The heated air is then exhausted from the outer enclosure. The appliance includes blowers or other air moving devices that circulate the layers of air at a selected rate to optimize the amount of heat transfer for a given amount of heat generated in the combustion chamber in order to maintain a certain temperature for the appliance exposed surface. The heating appliance may also include a separate venting assembly for providing fresh combustion air to the combustion chamber and exhausting combustion gases from the combustion chamber.

A central aspect of the invention relates to controlling the amount of radiant heat provided to a living space by the heating appliance. This type of radiant heat control is possible by varying a blower speed thereby altering the rate of air moving between the front panels of the heating appliance and the combustion chamber of the heating appliance. This radiant heat control is possible without altering the amount of radiant heat being produced by the heating appliance. As a result, it is possible to provide a whatever fire display desired within the heating appliance while separately controlling the amount of radiant heat (and other heat) that enters the living space wherein the heating appliance is exposed.

As used herein, the term “combustion chamber enclosure” may be any structure that at least partially surrounds that portion of the heating appliance in which combustion or heat generation occurs. A combustion chamber enclosure typically includes a plurality of panels that define a combustion chamber for the combustion of fuel or generation of heat using other means. The phrase “living space” will be understood to mean the interior or inner portion of any dwelling structure, such as a house or office building that at least partially protects from the elements. The term “room” is defined as an area of the living space in which the heating appliance resides. The phrase “outside of a living space” will be understood to mean the exterior or outer portion of a dwelling structure, which is typically exposed to various weather elements such as rain, snow, wind, etc.

While the example embodiments of the present invention provided below are described in conjunction with direct vent fireplaces, the present invention is equally applicable to other heating appliances such as, for example, a universal vent, a B-vent, a horizontal/vertical-vent, a dual direct vent, and a multisided heating appliance having two or three glass panels as combustion chamber side panels. Although the present invention may be particularly useful for a fireplace, as described below, many principles of the present invention may be applied to closed front fireplaces, stoves, furnaces, fireplace inserts and similar heat generating appliances that include an otherwise heated exposed surface.

Referring now toFIGS. 1-6, an example fireplace assembly10that illustrates principles of the present invention is shown and described. Fireplace10includes an outer enclosure12, a combustion chamber enclosure14, an interior panel16, first and second vent assemblies18,20, first and second doors22,24, and a direct vent assembly26. The interior panel16is positioned between a front panel of the combustion chamber enclosure14and a front panel of the outer enclosure12, thereby defining first and second air chambers40,42. Fireplace10also includes a burner assembly28positioned within the combustion chamber enclosure, and first and second side interior panel supports30,32, a bottom interior panel support34, a baffle36, and a top support member38all positioned within the outer enclosure12. The supports30,32,34,38and baffle36function to separate, isolate, and direct air through the first and second air chambers40,42.

The outer enclosure12includes top and bottom panels50,52, front and first and second rear panels54,56A,56B, and first and second side panels58,60that define an enclosure within which the combustion chamber enclosure14and other features of fireplace10may be positioned. First and second intake openings62,64and a second exhaust opening72may be formed in the front panel54to provide for airflow through the first air chamber40. A direct vent opening66may be formed in the top panel52to provide access for the direct vent assembly26to engage the combustion chamber enclosure14. A first exhaust opening68that is also formed in the top panel50provides airflow between the second air chamber42and the first vent assembly18. A third intake opening70defined by the first and second rear panels56A,56B provides for airflow between the second air chamber42and the second vent assembly20.

The outer enclosure12is shown in the Figures as being constructed of several independent panels that are secured together in the shape of a rectangular box. Other embodiments may include different shaped outer enclosures or outer enclosures with multiple panels formed together as a unitary piece. Further, the outer enclosure may have intake and exhaust openings formed in different panels than those shown in the Figures. For example, the direct vent opening may be positioned on one of the side or rear panels, or the fireplace may include a co-linear exhaust system rather than a direct vent opening such that two separate openings are required for providing fresh combustion air and removal of combustion gases from the fireplace combustion chamber enclosure14.

The combustion chamber enclosure14may include top and bottom panels72,74, front and rear panels76,78, and first and second side panels80,82that together define a combustion chamber84. Combustion chamber enclosure14may also include an exhaust opening86formed in the top panel72. The bottom panel74may include a plurality of combustion air intake openings (not shown) for communication of combustion air from the direct vent assembly26into the combustion chamber84for the combustion of fuel at the burner assembly28.

The combustion chamber enclosure14is shown in the Figures as a generally rectangular shaped box defined by the plurality of panels72,74,76,78,80,82. Other embodiments may include different shapes, sizes and configurations for the combustion chamber enclosure. Some embodiments may include a combustion chamber enclosure that is formed as a single unitary body (with exception of the removable front panel) using, for example, a molded material such as a ceramic fiber and a binder. Such molded materials may be used to form the combustion chamber enclosure using such molding techniques as compression molding, vacuum molding, or casting as described in U.S. Publication No. 2003/0049575 A1, which is incorporated herein by reference.

The first vent assembly18includes an air collection enclosure90and a first duct92. The air collection enclosure90is positioned over the first exhaust openings68thereby providing fluid communication with the first air chamber40. The enclosure90may be shaped to cover any configuration for openings68. In other embodiments, the first duct92may be coupled individually to the openings68.

The second vent assembly20includes a second duct100, a second duct support102positioned beneath the combustion chamber enclosure14, an aperture106formed in the second duct support102, and a blower104. The blower104may be configured to force a source of fresh air through the second duct100into the second air chamber42and then out of the first vent assembly18. In other embodiments, the blower104may be configured to create a vacuum force that draws air into the second air chamber42through the first vent assembly and back out of the second duct100. The blower104may be positioned at a remote location from the outer enclosure12, or may be positioned within the outer enclosure12. Advantages of positioning the blower at a remote location include a reduction in blower noise heard by a user positioned at the front panel54, and a reduced size requirement for the fireplace outer enclosure that is otherwise required if the blower is positioned therein.

The blower104may be coupled to a source of fresh, outside air or any other source of air that has a temperature lower than the temperature of air within the outer enclosure12. Using air that is relatively cool compared to the temperature of air in the air chambers40,42and panels of the combustion chamber enclosure14improves the heat transfer away from the combustion chamber enclosure14.

In the illustrated embodiment, the second duct100extends underneath the combustion chamber enclosure14and through the aperture106in the second duct support102so as to provide fluid communication directly with the isolated second air chamber42. The second air chamber42extends along the front surface of the combustion chamber enclosure14and is not in fluid communication with the first air chamber40, or the air plenum defined between the outer enclosure12and the top, sides, and rear surfaces of the combustion chamber enclosure14. In other embodiments, the second air chamber42may have different shapes and sizes and may extend around other surfaces of the combustion chamber enclosure besides the front panel surface only. In such embodiments, the second duct100may be repositioned to be coupled to an outer surface of the outer enclosure12such as, for example, the top, sides, or rear panels of the outer enclosure12rather than extending under the combustion chamber enclosure14.

The baffle36positioned in the second air chamber42may assist in directing air in the second air chamber42into or out of the second duct100. The first and second side interior panel supports30,32and the bottom interior panel support34along with the second duct support102may be used to further define the second air chamber42between the outer enclosure panels, the interior panel16, and the combustion chamber enclosure panels. These various supports may be positioned in alternative locations within the outer enclosure12to redefine the shape and size of the first and second air chambers40,42.

The first air chamber40is defined between the interior panel16and the front panel54and doors22,24positioned at the front of the outer enclosure12. Access to the first air chamber40is provided through the first and second intake openings62,64positioned along a bottom side of the doors22,24, an outlet or a second exhaust opening72positioned above the doors22,24, and through the doors22,24themselves. One way in which heat generated in the combustion chamber enclosure14can be further removed from the outer enclosure12to maintain a reduced temperature of the exposed front surfaces of the outer enclosure (e.g., the front panel54and doors22,24) is to operate a pair of first and second blowers94,96that circulates air through the first air chamber40. The blowers94,96are shown positioned along the bottom panel52of the outer enclosure in alignment with the first and second intake openings62,64. The blowers94,96, draw air into the first air chamber40through the intake openings62,64, and force air out of the second exhaust opening72. The flow of air through the first air chamber is heated and then forced out of the fireplace10in a direction away from the exposed surfaces of the fireplace10. Even when the blowers94,96are not in operation, a natural convection occurs within first air chamber40as heated air exits the second exhaust opening72creating a draft that draws in relatively cool air through the first and second intake openings62,64. Directing blown air from blowers94,96onto the doors22,24and front panel54may enhance transfer of heat from those surfaces into the flow of air and improve heat transfer efficiency.

Another way of transferring heated air out of the first air chamber40is to open the doors22,24. Opening the doors22,24may further enhance the transfer of radiant, infrared, ultraviolet, and other types of heat generated by the burner assembly28and the combustion chamber enclosure14directly out into the living space rather than heating the doors22,24and the front panel54.

Opening and closing of the doors may be automated or mechanically operated using a motor or other automated means. An example automated system of opening doors is disclosed in U.S. patent application Ser. No. 10/794,424 entitled AUTOMATIC DOORS FOR A FIREPLACE and filed on Mar. 5, 2004, which is incorporated herein by reference. Opening or closing the doors22,24may affect the amount of radiant heat being passed into the living space. The extent to which the doors are open or closed may also affect how the radiant heat is directed into the living space. For example, for two persons sitting side-by-side in front of the fireplace, opening or closing the doors22,24can customize the amount of radiant heat felt by each person.

The fireplace10may further include and on/off switch130associated with one or more of the doors22,24that controls operation of the first and second blowers94,96upon opening or closing the doors22,24. In some embodiments, opening one or more of the doors22,24eliminates the need to operate the blowers94,96for transferring heat out of the first air chamber40. In some embodiments, opening one or more of the doors22,24while the blowers94,96are operating may provide for undesired amounts of blower noise to the user or may provide excessive airflow out of the doors22,24. The on/off switch130may automatically turn the blowers94,96on or off depending on an open or closed position of the doors22,24.

The direct vent assembly26may include a fresh air chamber110, exhaust vent112, a fresh air vent114and a combustion air opening116. The fresh air chamber110extends from the top of the combustion chamber enclosure14where the fresh air vent114engages to around the rear panel78to a location where a combustion air opening is provided into the combustion chamber84adjacent to the burner assembly28. The rear or bottom panel78,74or the side panels80,82may include the air openings into the combustion chamber84depending of the configuration of the fresh air chamber110and other features of the fireplace10.

The exhaust vent112extends coaxially with the fresh air vent114and passes through the exhaust opening86formed in the top panel72to provide an exhaust path for combustion gases and heated air within the combustion chamber84. Preferably, a direct vent duct is coupled to the exhaust and fresh air vents112,114and extends out of the direct air vent opening66in the top panel50of the outer enclosure12. An auxiliary exhaust vent112A and an auxiliary fresh air vent114A may be provided along the rear panel78of the combustion chamber enclosure for coupling of a direct vent duct through a rear panel of the outer enclosure12for horizontal direct venting rather than vertical direct venting. As noted above, alternative venting structures may be used such as B-vents, co-linear venting, and other venting arrangements to provide exhaustion of combustion gases and provide a source of fresh combustion air for the combustion chamber84.

The burner assembly28may include a burner plate120and an ignition assembly122. The ignition assembly122provides a pilot light and other ignition features that light the burner plate for the production of heat within the combustion chamber84.

The illustrated embodiment provides for first and second air chambers40,42that are sealed from each other. Such separate air chambers permits individualized control of venting from each of these air chambers. Thus, different rates of airflow may be possible in each air chamber to optimize the heat transfer to meet predetermined temperatures of the exposed features of the fireplace (e.g., the doors22,24and front panel54of the outer enclosure12). Optimizing the heat transfer may be dependent on the temperature of the cool air provided to the first and second air chambers40,42. For example, if the second vent assembly20is coupled to a source of cool air outside of the building structure, that source of air may vary widely in temperature depending on the time of day or the day of the year. Depending on the temperature of that source of outside air, the blower may be adjusted to provide a reduced or an increased airflow rate to alter the amount of heat transfer provided by the second air chamber42. Likewise, the blowers94,96may be adjusted in rate depending on the room temperature in the room from which they draw air into the first air chamber40.

In still further embodiments, an adjustable opening may be provided between the first and second air chambers so as to alter where the first and second air chambers exhaust heated air and/or from what source of cool air is air drawn into the first and second air chambers. In one example, it may be possible to close one or more of the intake openings62,64and provide cool fresh air into the first air chamber from a remote location such as, for example, cool air provided by the second vent assembly20. In other embodiments, the second exhaust opening72may be restricted or covered and the heated air in first air chamber40may be exhausted to a different location such as, for example, through the first vent assembly18, or into the direct vent exhaust vent112. Any number of variations for the intake of cool fresh air and exhaust of heated air from the first and second air chambers40,42is possible to provide a desired heat transfer effect to reduce the temperature of an exposed surface of the fireplace10.

Using different sources for the intake and exhaust of heated air related to the first and second air chamber40,42can also influence a pressure condition in the living structure towards a positive or a negative pressure. A recommended pressure condition for a living structure relates to the amount of air entering or leaving the living structure. In one example, about 50 to 100 cubic feet per minute (cfm) either entering or leaving a living structure at any given time is preferred. The fireplace10may help to optimized the pressure condition in the living structure by altering the intake and exhaust sources for the airflow in the chambers40,42.

Another way in which the fireplace10may be modified to further increase heat transfer so as to maintain a reduced temperature of exposed surfaces of the fireplace10is to exhaust heated air out of the fireplace that is positioned within the plenum defined between the outer enclosure12and the combustion chamber enclosure14. This plenum (not numbered) includes air that is not in communication with one of the first and second air chambers40,42. In one example, the heated air within that plenum may be exhausted into the exhaust vent112. In another example, the heated air within that plenum may be exhausted into one of the first or second vent assemblies18,20. In a yet further embodiment, a separate exhaust duct may be coupled to a panel of the outer enclosure112to provide the flow of heated air out of the plenum. A blower may be associated with such an additional exhaust duct to force heated air out of the plenum and exhaust that heated air to a remote location.

Referring now toFIGS. 7-13, another example fireplace assembly that illustrates the principles of the present invention is shown and described. Fireplace200includes an outer enclosure212, a combustion chamber enclosure214, and an airflow assembly216. A top or a rear direct vent assembly220,222may be used to provide combustion air and remove exhaust and exhaust gases from the fireplace200. A combustion air channel224couples the combustion air provided by the direct vent assemblies220,222to a combustion chamber291defined by a combustion chamber enclosure214.

Referring to theFIG. 8, the airflow assembly216includes a blower218, a top panel236having a vent opening237, a bottom panel238having a side wall240, a divider242, and an exhaust panel244having an airflow exhaust opening246. The airflow assembly216provides an airflow through a series of top, bottom and front airflow plenums226,228,230defined between the outer enclosure212and the combustion chamber enclosure214. The intake source of air for the airflow may be at a remote location or may be from within the living space within which the fireplace200resides. Likewise, the exhaust outflow for the airflow may be a remote destination or may be the living space in which the fireplace200resides.

The outer enclosure212includes top and bottom panels250,252, front and rear panels254,256and first and second side panels258,260. The outer enclosure212also includes a top vent opening262associated with the top direct vent assembly220, a rear vent opening264associated with the rear direct vent assembly222, an airflow intake opening266, an airflow exhaust opening268and a front frame member270. While the airflow intake and exhaust openings266,268are shown formed in the second side panel260, these openings266,268may be positioned on opposing side panels or any combination of the top and bottom, rear, and first and second side panels250,252,256,258,260. Likewise, the top and rear vent openings262,264may also be formed in either of the side panels258,260.

The combustion chamber enclosure214includes top and bottom panels272,274, front and rear panels276,278, and first and second side panels280,282that together define the combustion chamber291. The front panel276and the front panel254of the outer enclosure212preferably include a transparent panel that provides viewing from outside of the fireplace200into the combustion chamber291. Typically, a heat generating source such as a burner or electric heating element is positioned within the combustion chamber291along with an artificial or actual flame display. The combustion chamber enclosure214also includes top and rear vent openings280,282associated with respective top and rear direct vent assemblies220,222, a combustion air opening284in fluid communication with the combustion air channel224, a blower access opening286, a blower opening panel288, and a top vent shield290.

As shown inFIGS. 12 and 13, the combustion chamber enclosure214is positioned within the outer enclosure and spaced apart from the outer enclosure a sufficient distance to help define the bottom, top and front airflow plenums226,228,230. For example, the combustion chamber enclosure214is spaced rearward in the outer enclosure212a distance sufficient for a space or front airflow plenum230to be defined between the front panel254of the outer enclosure212and the front panel276of the combustion chamber enclosure214. In another example, the combustion chamber enclosure214is spaced vertically lower from the top panel250of the outer enclosure212so that the top panel236of the airflow assembly216can be positioned there between and define the top airflow plenum228between the top panel236and the top panel272of the combustion chamber enclosure214. In a third example, the combustion chamber enclosure214is spaced vertically above the bottom panel252of the outer enclosure212so that the bottom panel238of the airflow assembly216can be positioned there between. The bottom airflow plenum226is defined between the bottom panel274of the combustion chamber enclosure214and the bottom panel238of the airflow assembly216.

The blower218of the airflow assembly216is shown in further detail inFIGS. 10 and 11. The blower218includes a top panel292, an outer panel294, an inner panel296, a blower wheel298, and an airflow intake opening300. The airflow intake opening300provides an inlet air opening for intake airflow A (seeFIG. 12), wherein the airflow is accelerated by the blower wheel298and forced into the bottom airflow panel226(seeFIGS. 12 and 13). The bottom panel238of the airflow assembly216includes a side wall240that helps direct the airflow in the bottom airflow plenum226toward a front of the fireplace200where an opening to the front airflow plenum230is provided between the front panels254,280. As the airflow passes through the front airflow plenum230, the airflow absorbs radiant heat passing from the combustion chamber291through the front panel276of the combustion chamber enclosure214while at the same time removing heat from the front panel254, thereby cooling the front panel254. Thus, by passing the airflow through the front airflow plenum230, the front panel254, which is exposed within the living space in which the fireplace200resides, can be cooled while at the same time controlling the amount of radiant heat passing from the combustion chamber291through the front panels254,276to the living space.

The airflow moves from the front airflow plenum230into the top airflow plenum228. The top airflow plenum228is defined across a portion of the top panel272of the combustion chamber enclosure214and may also extend around a portion of the top direct vent assembly220and the combustion air channel224. In some embodiments, the top airflow plenum228may extend around the combustion chamber enclosure214to the plenum space defined between the rear panel278of the combustion chamber enclosure214and the rear panel256of the outer enclosure212. The divider242and exhaust panel244define an airflow path from the top airflow plenum228towards the airflow exhaust opening246.

The airflow exhaust opening246may be coupled to any desired location via some type of exhaust or vent passage. For example, the heated airflow exiting the airflow exhaust opening246may be transferred to the living space in which the fireplace200resides, to another location within the living structure but outside of the living space within which the fireplace200directly resides, or to a location outside of the living structure altogether. In one example, the temperature of the living space can be closely controlled by varying the blower speed to control the amount of heat output from the fireplace200into the living space without altering the rate of heat generation in the combustion chamber. One example of this type of control is possible when the airflow intake opening300of the blower218is coupled to a source of outside fresh air (air outside of any living structure) and the airflow exhaust opening246is coupled to atmospheric air outside of the living structure as well.

One advantage of the example configuration shown inFIGS. 7-13is that the blower218can be automatically controlled to help maintain a predetermined temperature in the living space. For example, the controller232can control of the blower speed based on a user input. The user input may come via a thermostat setting or from a temperature input signal provided by a thermostat234that is positioned within the living space. The thermostat may be mounted within or otherwise associated directly with the fireplace200. In some embodiments, the thermostat may directly control the blower without the intervening controller232. The controller may be integrated into a thermostat in some embodiments.

The blower speed may be reduced in order to increase the temperature of the living space in order to meet a predetermined temperature set by the thermostat, or the blower speed may be increased in order to reduce a temperature in living space until it meets the predetermined temperature set with the thermostat234. In some embodiments, the blower maintains an on state when a predetermined temperature exists in the combustion chamber291. For example, the blower may automatically turn on after a predetermined time period after combustion (or other heat generation) is initiated in the combustion chamber291. Likewise, the blower may automatically turn off after a predetermined time period after combustion (or heat generation) ends in the combustion chamber291.

In still further embodiments, the temperature of the exposed front panel254is monitored and the blower is controlled (e.g., on/off or increase/decrease blower speed) based on the monitored temperature. In one example, the blower is turned on after a threshold temperature of the panel254is reached and is incrementally increased in speed as the temperature continues to increase. Likewise, the blower may be decreased in speed as the monitored temperature of the panel254is reduced in temperature and eventually turned off when the panel temperature drops below a threshold temperature.

The airflow through the plenums226,228,230may also help cool the combustion air channel224and thus help maintain a cooler temperature of the incoming combustion air. In many situations, it is preferred to have relatively cool combustion air entering the combustion chamber291for improved combustion efficiency. A still further advantage of fireplace200is that the intake airflow and exhaust airflow B can be coupled to any desired source or location. This provides improved adaptability of the fireplace200for the user to provide certain airflow and heating scenarios within the living structure.

In some embodiments, the blower218may be positioned outside of the outer enclosure212and still provide the same or similar function of forcing the airflow through (pushing force) the fireplace200or for drawing the airflow through (pulling force) the fireplace200. In one example embodiment, the blower is positioned at the termination point of either the intake or exhaust line that is fed to the fireplace200. Positioning the blower at a remote location may be advantageous for reducing noise output of the fireplace200. In other embodiments, more than one blower may be used to move the airflow. In still further embodiments, other blowers may be used to move fluids into or out of the combustion chamber291or to move air through plenum spaces defined between the outer enclosure212and the vent panels236,238.

Another advantage of fireplace200is that it provides cooling of front panel254of the outer enclosure. Cooling of the front panel254improves the safety of fireplace200and reduces the likelihood of harm caused to persons in close proximity to the fireplace200while the fireplace is in use.

The airflows A, B (seeFIG. 12) that pass through the fireplace200may be part of a closed ventilation system that is fluidly separated from air within the living structure wherein the fireplace200resides. This closed system can be maintained if the source for the airflow A is atmosphere outside the living structure and the exhaust location for the airflow B is also atmosphere outside the living structure. In some circumstances, it is advantageous to maintain separation of the airflows A, B so that the pressure condition of the living structure is not affected by the fireplace200.

In an alternative embodiment (not shown), the fireplace200may include at least one door in place of front panel254that provides access to the front plenum230. The door may be automated according to principles discussed in U.S. patent application Ser. No. 10/794,424 discussed above. In other embodiments, the fireplace200may include damper or other variable position members that provide variable flow control of room air into the airflows A, B.