Abstract:
A heating appliance having a housing which houses a water and air heating system. The water heating system includes a heat source and a first heat exchanger for transferring heat to a working fluid passing through the housing. The air heating system includes a water-to-air heat exchanger in communication with the working fluid and a source of air, for heating air using the working fluid. The housing defines an upper compartment for the heat source and first heat exchanger, and a lower compartment for the water-to-air heat exchanger.

Description:
PRIORITY 
       [0001]    This application claims priority to Great Britain Patent Application No. GB1307141.0, entitled “HEATING APPLIANCE,” filed on Apr. 19, 2013, also naming Dee et al. as inventors, the disclosure of which is hereby incorporated by reference in its entirety. 
       FIELD OF THE DISCLOSURE 
       [0002]    The present invention generally relates to heating appliances and, more particularly, to a heating appliance which incorporates a water heating device. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is common for a domestic dwelling to include a heating appliance, for providing a source of hot water for bathing and/or use in a central heating system. Such appliances are often referred to generically as ‘boilers’. 
         [0004]    There are numerous types of heaters available on the market. Recent years have seen a call for heaters with improved efficiency. A variety of developments have arisen, such as incorporating a power generation mechanism into a heater in order to provide a combined heat and power apparatus. Nevertheless, further advancements are needed. 
       SUMMARY OF THE INVENTION 
       [0005]    Illustrative embodiments of the current invention provide alternative heating appliances. According to one aspect of the invention, there is provided a heating appliance having a housing which houses both a water heating system and an air heating system. The water heating system includes a heat source and a first heat exchanger for transferring heat to a working fluid passing through the housing. The air heating system includes a water-to-air heat exchanger in communication with the working fluid and a source of air, for heating air using the working fluid. The housing defines an upper compartment for the heat source and first heat exchanger, and a lower compartment for the water-to-air heat exchanger. 
         [0006]    Other aspects and features of the invention will be readily apparent from the following description of one or more illustrative embodiments, made by way of example, with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0007]      FIG. 1  is a schematic view from the front of a heating appliance incorporating a water heating system and an air heating system, according to an illustrative embodiment of the present invention; 
           [0008]      FIG. 2  is a schematic view from one side of the heating unit of  FIG. 1 ; 
           [0009]      FIG. 3  is a schematic perspective view of the heating unit of  FIGS. 1 and 2 , with the filter cassette in an open position; 
           [0010]      FIG. 4  is similar to  FIG. 1  but shows the front cover removed; 
           [0011]      FIG. 5  is similar to  FIG. 2  but shows the side cover removed; 
           [0012]      FIG. 6  is a schematic perspective view showing principal components of the water and air heating systems of the heating unit of  FIGS. 1 to 5 ; 
           [0013]      FIG. 7  is an enlarged view from a region of  FIG. 6 ; 
           [0014]      FIG. 8  is a schematic view of the heating unit of  FIGS. 1 to 7 , showing the path of air flow in an air heating mode; 
           [0015]      FIG. 9  is a schematic showing the water and air heating circuits of the heating unit; and 
           [0016]      FIG. 10  is a schematic showing an illustrative application for the heating unit in a domestic environment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Illustrative embodiments and related methods of the present disclosure are described below as they might be employed in a heating appliance incorporating a water and air heating system. In the interest of clarity, not all features of an actual implementation or method are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. Further aspects and advantages of the various embodiments and related methodologies of the disclosure will become apparent from consideration of the following description and drawings. 
         [0018]    Referring to the illustrative embodiment of  FIGS. 1 and 2 , a heating appliance is indicated generally at  10 . As will be apparent from the following description, the appliance  10  is in the form of a combined air heater and water heater, and so incorporates an air heating system and a water heating system. 
         [0019]    The air heating and water heating systems are provided in a common housing  12 . As will be described in more detail below, in certain embodiments the primary components of the water heating system are mounted in an upper part of the housing, whereas primary components of the air heating system are provided in a lower part of the housing. 
         [0020]    The housing  12  has a top wall  14 , a bottom wall  16 , opposing side walls  18 , a rear wall  20  and a front wall  22 . The housing  12  is generally rectangular in cross section. The housing  12  is deeper than it is wide. The housing  12  is configured for floor mounting, e.g. mounting on a plenum on the floor of a building or a similar support structure. 
         [0021]    As will be described in more detail below, and as can be seen most clearly from  FIG. 3 , the top wall  14  includes an air inlet  24  for allowing air to enter the appliance, and a flue turret  26  to allow exhaust gases to exit the appliance. The flue turret  26  is configured for connection to concentric flue ducts. The air inlet  24  is positioned rearward of the flue turret  26 , proximal the rear wall  20  of the housing  12 . The air inlet  24  is arranged in communication with an air duct of the appliance (described below with reference to  FIGS. 4 to 7 ). In addition, water inflow/outflow pipes  28 ,  30  extend through the top  14  of the housing  12  (side by side one another, between the air inlet  24  and the flue turret  26 ), by means of which the appliance  10  can connected as part of a hot water system. 
         [0022]    The front wall  22  of the housing  12  is formed from an upper cover  32 , a lower cover  34  (located below the upper cover  32 ) and a central cover  36  (located between the upper cover  32  and the lower cover  34 ). As will be apparent from the following description, the upper cover  32  is associated with an upper compartment of the housing  12  (for primary components of the water heating system) and the lower cover  34  is associated with a lower compartment of the housing  12  (for primary components of the air heating system). 
         [0023]    The central cover  36  forms part of drawer or cassette  38  which is movable along a horizontal axis between a stowed position (shown in  FIGS. 1 and 2 ) and an extended position (e.g. shown in  FIG. 3 ). The cassette forms part of filter system, for filtering air passing from the air inlet  24  to the air heating system, as will be described in more detail below. Accordingly, a replaceable air filter  40  is provided in the cassette  38 . A handle  42  is provided for engagement by a user during movement of the cassette  38 . 
         [0024]    The appliance  10  includes a user interface  44  (i.e. including controls for the appliance  10 ). In this embodiment, the user interface  44  is mounted behind a movable panel  46 . The movable panel  46  is provided in the upper cover  32  of the housing  12 . The panel  46  is movable between a closed position (see  FIGS. 1 and 2 ), in which controls on the user interface are hidden from operation, and an open position (e.g. as shown in  FIG. 3 ), in which controls on the user interface  44  can be accessed by a user. 
         [0025]    Referring now to the illustrative embodiments of  FIGS. 4 and 5 , it can be seen that the housing  12  effectively defines two compartments: an upper compartment  48  in which primary components of the water heating system are mounted, and a lower compartment  50  in which primary components of the air heating system are mounted. 
         [0026]    Between the upper and lower compartments  48 ,  50 , the appliance  10  defines an intermediate compartment  52  into which the filter cassette  38  can be received. As can be seen most clearly in  FIGS. 6 and 7 , the intermediate compartment  52  includes running surfaces  54  on which the cassette  38  is slidably movable, i.e. between its stowed and open positions. 
         [0027]    An air duct  56  extends from the base of the upper compartment  48  to the air inlet  24 . The air duct  56  is used for directing air towards the lower compartment  50  after entering the appliance though the air inlet  24  at the top of the housing  12 . Although not visible in the drawings, the lower end of the air duct  56  defines an air outlet, for directing incoming air into the intermediate compartment  52 , i.e. so that the air passes through the air filter in the filter cassette  38  when the cassette is in its stowed position. This prevents unwanted particles from entering the lower compartment  50  via the air duct  56 . 
         [0028]    In general terms, the water heating system includes a heat source mounted in the upper compartment  48  and arranged so that operation of the heat source causes heating of a supply of water. In illustrative embodiments, the heat source takes the form of a gas boiler. In the illustrated embodiment, the heat source takes the form of a gas-fired condensing heat exchanger unit  60 , e.g. of known construction. However, other forms of heat source may be incorporated, e.g. other kinds of fuel-fired boilers or heat exchangers, or an engine (e.g. a sterling engine or ic-engine) having a heat exchanger in communication with an exhaust of the engine. 
         [0029]    In this illustrative embodiment, the heat exchanger unit  60  is mounted on an outer wall  72  of the air duct  56 , by opposing brackets  74 . As can be seen, the heat exchanger unit  60  is arranged in front of the air duct  56 , with respect to the rear wall  20  of the housing  12 . In use, incoming water is directed into the heat exchanger unit  60  via heat conductive pipe work (e.g. copper pipe), where it is heated by heat transfer to the pipe work, and then directed out of the heat exchanger unit  60 . This is described in more detail below with reference to  FIGS. 7 and 8 . 
         [0030]    The appliance  10  includes a condensate trap  66 . In the illustrated embodiment, the condensate trap  66  is located below the heat exchanger unit  60 , more particularly in the lower compartment  50 . Condensate is able to flow to the trap  66  under gravity via a condensate conduit  68  arranged between the heat exchanger unit  60  and the condensate trap  66 . 
         [0031]    In this illustrative embodiment, an external supply of gas is connectable to the appliance  10 , e.g. via a cock  69 , and the appliance  10  includes a gas valve  70  for controlling the supply of gas to the heat exchanger unit  60 . Exhaust gases from operation of the heat exchanger unit  60  are expelled through the roof of the appliance  10  via the flue turret  26  in the top wall  14  of the housing  12 . 
         [0032]    In general terms, the air heating system consists of a water to air heat exchanger  78  mounted in the lower compartment  50  of the housing  12 . In use, heated water from the water heating system is directed down to the lower compartment and through the water to air heat exchanger  78 . The air heating system also includes an air fan  76  for collecting air present within the lower compartment (i.e. having passed though the filter cassette  38  from the air duct  56 ), and an air transition guide  80  for directing air from the air fan  76  to the water to air heat exchanger  78 . The fan  76  and air transition guide  80  are mounted in the lower compartment  50 . 
         [0033]    The water-to-air heat exchanger  78  is mounted on the base wall  16  of the housing  12 . In general terms, the water to air heat exchanger  78  consists of a box  82  for receiving air from the transition guide. It also includes plurality of water conduits  84  extending within the box  82 . As will be described below, in an air heating mode of operation for the appliance  10 , heated water is conveyed through the conduits  84  in order to heat air within the box  82 . Although not visible in the drawings, one or more air outlets are provided for directing heated air out of the box  82  and the appliance. The air outlet(s) may, for example, be in the base wall  16  of the housing. One or more air ducts may be connected to the air outlet(s), for conveying the heated air to a demand location remote from the appliance. 
         [0034]      FIG. 8  illustrates an illustrative airflow path for the appliance  10  in an air heating mode. Other primary components of the appliance are illustrated schematically in  FIG. 9 . These include a pump  86 , and a diverter valve  88 . 
         [0035]    An illustrative method of operation for heating water via the appliance  10  will now be described with reference to  FIGS. 1 to 9 . Water is supplied to the appliance  10  via inlet pipe  28 . Pump  86  and diverter valve  88  are operated to cause water to be driven through the heat exchanger unit  60 . When the heat exchanger unit  60  is operating, the water is heated as it passes through the heat exchanger unit  60 . The user interface can be used to set the desired temperature. 
         [0036]    Condensate from operation of the heat exchanger unit  60  is collected in the condensate trap. Any exhaust gases from operation of the heat exchanger unit  60  expelled through the turret  26 . The heated water can be delivered to demand location, e.g. external to the appliance  10 . However, if air heating is required, at least a proportion of the heated water is diverted to the water-to-air heat exchanger  78 . The air circulation fan is operated to draw air into the unit via the inlet  24  and air duct. The air is delivered into the water-to-air heat exchanger  78  and heat is transferred to the air as it passes through the water-to-air heat exchanger  78 . 
         [0037]    Accordingly, it will be understood that the combined water and air heating appliance  10  is operable to heat water and provide a source of heated air. 
         [0038]    The user interface can be used to automate the air-heating and water heating modes of operation, e.g. on a timer. In addition, the unit can be utilized to provide ventilation, by operation of the air fan without the use of heated water in the water-to-air heat exchanger  78 . The appliance may be configured to override the warm air heating function if a heated water demand is made to the appliance. 
         [0039]    An illustrative use for the appliance  10  is illustrated in  FIG. 7 , where the appliance  10  forms part of a hot water system  100  in a domestic dwelling. The hot water system  100  includes a water heating circuit  102  and a hot water supply  104 . The appliance  10  is used to heat water in the water heating circuit  102 . The heated water is then conveyed away from the appliance  10  through a supply conduit  106 . The supply conduit  106  directs the heated water to a transfer conduit  108 , which extends inside a storage cylinder  110 . The transfer conduit  108  is connected between the supply conduit  106  and a return conduit  112 , such that the water is directed back to the appliance  10  after passing through the storage cylinder  110 , e.g. for reheating and recirculation within the water heating circuit  102 . 
         [0040]    The storage cylinder  110  receives a supply of water from a cold water storage tank  114 . The heated water from the appliance  10  is used to heat the water in the cylinder  110 . The heated water in the cylinder can then be used on demand via the hot water supply  104 . A feed tank  116  is arranged in communication between the supply conduit  106  and the return conduit  112 , in order to complete the water heating circuit  102 . 
         [0041]    Accordingly, illustrative embodiments of the present invention provide a combined warm air and water heating unit. Separation of the key components of the water heating and warm air heating systems between upper and lower parts of the housing, with incoming air ducted down through the upper part of the housing to the lower part of the housing has been found to optimize packaging of key components of the appliance for use as a floor-mounted heating unit. Mounting the condensing heat exchanger on the air duct has been found to contribute to reduced noise and vibration. Also, arranging the heat source in front of the air duct has allowed for simplified access for maintenance. The provision of a filter system between the two parts of the housing has also provided advantages in terms of packaging, assembly and maintenance. The use of a sliding filter cassette has provided further advantages in this regard. 
         [0042]    While certain features and embodiments of the disclosure have been described in detail herein, it will be readily understood that the disclosure encompasses all modifications and enhancements within the scope and spirit of the following claims. Furthermore, no limitations are intended in the details of construction or design herein shown, other than as described in the claims below. Moreover, those skilled in the art will appreciate that description of various components as being oriented vertically or horizontally are not intended as limitations, but are provided for the convenience of describing the disclosure. 
         [0043]    It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present disclosure. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined herein.