FURNACE

Abstract

A furnace which receives input information of various sources, distinct from a thermostat, and can vary heat output based on the input information. Examples of input information include without limitation exhaust temperature, temperature near the heat exchanger compartment, temperature sensors within the housing, air pressure, motor RPM, and/or motor amperage. Heat output may be varied by one or more of combustion fan output, fuel flow to burners, combinations or other ways.

Claims

1. A furnace, comprising: a housing having a plurality of walls, said plurality of walls having one or more knock-out blanks disposed in one or more of said plurality of walls; a combustion blower and a motor, said combustion blower providing air to a burner; a heat exchanger arranged within said housing and receiving a flame from said burner; a fuel supply in flow communication with a first valve and a second valve; a first orifice in flow communication with said first valve, and a second orifice in flow communication with said second valve; and one or more sensors which provide a characteristic to a controller in order to vary heat output of the furnace, independent of a thermostat control.

2. The furnace of claim 1, said one or more sensors measuring one or more of temperature, pressure, amperage, or blower motor RPM.

3. The furnace of claim 1, said first orifice having a first output value and said second orifice having a second output value.

4. The furnace of claim 3, said first output value and said second output value being different values.

5. The furnace of claim 1 said first and second orifices having in combination at least three output options.

6. The furnace of claim 1, said controller configured to varying output speed of said combustion blower and said motor.

7. The furnace of claim 6, said controller configured to vary the heat output of said furnace.

8. The furnace of claim 1 further comprising a second blower to supply air across said heat exchanger and output to at least one duct connected to the housing at at least one of said one or more knock-out blanks.

9. The furnace of claim 1, said controller comprising at least one circuit board.

10. The furnace of claim 9, said controller comprising at least one second circuit board.

11. The furnace of claim 1 wherein said motor rotates a house blower, or a second motor rotates said house blower.

12. The furnace of claim 1, further comprising a Hall Effect sensor to verify said combustion blower is rotating before igniting said burner.

13. A furnace, comprising: a housing having a plurality of walls, one or more knock-out blanks configured to be connected to one or more ducts, respectively; a combustion blower and a motor which rotates said combustion blower, said motor being a variable speed motor to vary output of said combustion blower; a fuel supply in flow communication with a valve; said valve being adjustable to provide varying output to a burner; and, one or more sensors which provide input to a controller, said controller configured to vary an output of the furnace independent of a thermostat; wherein said one or more sensors measure one or more of temperature, pressure, amperage or motor RPM.

14. The furnace of claim 13, said one or more sensors disposed within said housing.

15. The furnace of claim 13, said valve being two valves wherein said varying output comprises operating either one or both said two valves.

16. The furnace of claim 15, wherein one or both of said two valves having on-off capability or alternatively adjustable output capability.

17. The furnace of claim 13 further comprising a second blower.

18. The furnace of claim 17, said second blower operated by said motor or by a second motor.

19. A method of operating a furnace, comprising the steps of: sensing within a housing of said furnace at least one of temperature, pressure, blower fan motor RPM, or blower fan motor amperage; adjusting a heat output based on said sensing by: varying a combustion fan output; and/or varying a fuel flow to one or more burners.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0029] In order that the embodiments may be better understood, embodiments of a furnace will now be described by way of examples. These embodiments are not to limit the scope of the claims as other embodiments of a furnace will become apparent to one having ordinary skill in the art upon reading the instant description. Non-limiting examples of the present embodiments are shown in figures wherein:

[0030] FIG. 1 is a perspective view of an example recreational vehicle (RV), according to one or more embodiments;

[0031] FIG. 2 is a first schematic perspective view of a furnace with a portion of the housing removed and the heat exchanger removed, according to one or more embodiments;

[0032] FIG. 3 is a second schematic perspective view of the furnace of FIG. 2 depicted from an alternate angle, according to one or more embodiments;

[0033] FIG. 4 is a schematic view of various sensors that may be utilized within the example furnace, according to one or more embodiments;

[0034] FIG. 5 is a schematic view of an example controller, according to one or more embodiments; and,

[0035] FIG. 6 is a schematic view of a burner configuration, according to one or more embodiments.

DETAILED DESCRIPTION

[0036] It is to be understood that a furnace is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The described embodiments are capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of including, comprising, or having and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms connected, supported, coupled, and mounted, and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms connected and coupled and variations thereof are not restricted to physical or mechanical connections or couplings.

[0037] Reference throughout this specification to one embodiment, some embodiments or an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present teaching. Thus, appearances of the phrases in one embodiment, in some embodiments or in an embodiment in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0038] In addition, it should be understood that embodiments may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic-based aspects may be implemented in software (for example, stored on non-transitory computer-readable medium, executable by one or more processing units, such as a microprocessor and/or application specific integrated circuits (ASICs)). As such, it should be noted that a plurality of hardware and software-based devices, as well as a plurality of different structural components, may be utilized to implement the embodiments. For example, servers, computing devices, controllers, processors, etc., described in the specification can include one or more processing units, one or more computer-readable medium modules, one or more input/output interfaces, and various connections (for example, a system bus) connecting the components.

[0039] Relative terminology, such as, for example, about, approximately, substantially, etc., used in connection with a quantity or condition would be understood by those of ordinary skill to be inclusive of the stated value and has the meaning dictated by the context, for example, the term includes at least the degree of error associated with the measurement accuracy, tolerances (for example, manufacturing, assembly, use, etc. associated with the particular value. Such terminology should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression from about 2 to about 4 also discloses the range from 2 to 4. The relative terminology may refer to plus or minus a percentage (for example, 1%, 5%, 10%) or more, of an indicated value.

[0040] It should be understood that although certain drawings illustrate hardware and software located within particular devices, these depictions are for illustrative purposes only. Functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. In some embodiments, the illustrated components may be combined or divided into separate software, firmware and/or hardware. For example, instead of being located within and performed by a single electronic processor, logic and processing may be distributed among multiple electronic processors. Regardless of how they are combined or divided, hardware and software components may be located on the same computing device or may be distributed among different computing devices connected by one or more networks or other suitable communication links. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is configured in a certain way is configured in at least that way but may also be configured in ways that are not explicitly listed.

[0041] Referring now in detail to the figures, wherein like numerals indicate like elements throughout several views, there are shown in FIGS. 1-6, embodiments of a furnace, which may receive inputs other than a thermostat, and which allow the ability to vary the output of the furnace. A furnace is provided which may receive a temperature input, a pressure input, and/or an amperage input, all from sensors within the furnace housing in order to allow for adjustment of furnace output.

[0042] Referring now to FIG. 1, a vehicle 100 is shown in perspective view. The vehicle 100, in the depicted embodiment, is a recreational vehicle. However, various vehicle types may be utilized within the spirit of the present embodiments. For example, although a coach-type recreational vehicle 100 is illustrated, it should be appreciated that climate control systems may be used in or with any suitable recreational vehicle, including tow-behind RVs. Likewise, other recreational vehicles may include marine vehicles, such as numerous boats that have enclosed spaces requiring some climate control. Any of numerous types of RVs may utilize a furnace of the type described herein. People may employ recreational vehicles 100 for a variety of purposes, including transportation, cooking, eating, sleeping, entertaining, and the like. As such, the recreational vehicle 100 defines a passenger compartment 102, which may further comprise a bed, stove, table, restroom, or multiple compartments for storing items that passengers wish to take with them on their travels. Since people often spend significant time within the recreational vehicle 100, climate control of the passenger compartment 102 is desirable.

[0043] For heated climate control, heat may be provided by a gas-powered furnace (e.g., propane, natural gas, etc.), an electric heater, a water boiler heater, or the like. Present embodiments relate to gas-powered furnaces. One or more thermostats 60 are provided in the recreational vehicle 100 for inputting temperature settings, as well as other user interface for control of one or more furnaces, and/or air conditioning systems within the recreational vehicle 100. For example, one thermostat 60 may be located in the passenger compartment 102 which comprises a furnace 10, so as to provide heat only in the area or zone where needed.

[0044] In the figure, one example furnace 10 is shown having one or more ducts 19 connected to and extending from the furnace 10.

[0045] Referring now to FIG. 2, a schematic perspective view of a furnace 10 is provided. The furnace 10 may be installed in any of various locations within the recreational vehicle 100 (FIG. 1) and may be connected to ducts or ductwork 19 that move heated air through the recreational vehicle 100. In this view, the furnace 10 comprises a furnace housing 12 comprising a plurality of sides 14 defined by walls 15. Some of the sides 14 are removed in the depicted view, so that components of the furnace 10 may be seen.

[0046] The furnace housing 12 may comprise a plurality of sides 14 wherein one or more of the sides 14 may have one or more knock-out blanks 16. The knock-out blanks 16 provide for connection with one or more ducts 19 (FIG. 1) that move heat through the walls 15 of the building or the recreational vehicle 100 to desired registers.

[0047] The furnace 10 comprises a house blower 20 which is powered by a house blower motor 24 (FIG. 4). As the house blower motor 24 rotates, a blower wheel 26 of the house blower 20 rotates and moves air across a heat exchanger 70 (FIG. 4). The house blower 20 is represented by a housing 22 which may house both the blower wheel 26 and the motor 24. In some embodiments, the motor 24 may be a brushed DC motor, or in other embodiments the motor 24 may be a brushless DC (BLDC) motor which may also allow for the variable speed operation. In some examples, the brushed DC motor may comprise pulse width modulation control to provide variable speed operation.

[0048] The furnace 10 also may comprise a combustion blower 30 which provides combustion air. The combustion blower 30 may be separate from the house blower 20 and may comprise a separate motor. In other embodiments, the combustion blower 30 may be on the same axis as the house blower 20 so that a single house blower motor 24 may be used to drive operation of both the house blower 20 and the combustion blower 30. For example, in some embodiments a single motor may be used for both blowers 20, 30 where a lower cost product is desirable. In other embodiments, two motors may be use to provide independent control of the house blower 20 and the combustion blower 30. The combustion blower 30 may comprise a blower wheel 32 to move air for combustion. With additional reference to FIG. 6, a schematic view is shown for example explanation. According to some embodiments, the combustion blower 30 may provide air in two ways. The combustion blower 30 may provide primary air A.sub.p to the burner 50. This primary air A.sub.p is mixed with fuel before burning. Additionally, a second air flowsecondary air A.sub.sis provided to the flame at or after the burner 50. Together, the two air forms improve the combustion process.

[0049] The combustion blower 30 provides air to a burner 50 (FIG. 3) which mixes with a fuel supply to provide air-fuel mixture for combustion and push combustion heat through a heat exchanger 70 (FIG. 4), for example a heat exchanger tube.

[0050] The combustion blower 30 may move air through a manifold toward a burner 50 (FIG. 3), where the combustion flame is forced into the heat exchanger 70.

[0051] A fuel supply line 36 is also shown. The fuel supply may be, for example, propane, natural gas, kerosene, or diesel fuel. The fuel supply line 36 may move to a gas manifold 40 which may be in the form of a valve in some embodiments. In some embodiments, the gas manifold 40 splits the supply of fuel into two flows which go to two corresponding orifices 46, 48, wherein each valve 42a, 42b controls flow to the orifices 46, 48 respectively. The orifices 46, 48 may be of the same or differing fuel flows for differing combustion rates. In some examples, the orifices 46, 48 may be of first and second, different flow rates, so that each of the orifices 46, 48 may provide differing heat output values. Additionally, it should be clear that the valves 42a, 42b may be fully open or may be less than fully open to vary the heat output for each orifice 46, 48, respectively. Thus by changing the amount of fuel flow from each valve, the heat output may be within a range and is not limited to one heat output range. The orifices 46, 48 however provide an upper limit on the heat output value of the burner 50. Since the gas manifold 40 may include valves, the one or more orifices 46, 48 may be supplied fuel individually or in combination. Thus, in the example, there may be a first heat output from one orifice 46, a second heat output from a second orifice 48, and a third heat output from a sum combination of both of the orifices 46, 48. This configuration thus allows for three distinct heat outputs. However, other amounts of variation of output are within the scope of this teaching. The furnace 10 may also comprise a cut-off switch to cut electrical power to the furnace 10, so that the blower(s) and electric for the ignitor(s) are cutoff and cannot operate.

[0052] In one example, and with additional reference to the table below, one orifice 46 may provide a heat output of 10 k BTU, and the second orifice 48 may provide a heat output of 20 k BTU. Thus the heat output for the furnace 10 may be 10 k BTU, 20 k BTU, or 30 k BTU if both orifices 46, 48 are in operation together. While two orifices 46, 48 are shown, in some embodiments 3 or more may be used. Further, one or more gas valves 42 (42a, 42b, FIG. 6) may be used which may vary the fuel flow to each orifice 46, 48 so that heat output may be adjusted by merely adjusting the gas valve 42 and flow rate of fuel. The gas valve 42 may be an adjustable flow gas valve for example. In some embodiments, gas valve 42 may be a two-stage gas valve having a low flow rate and a high flow rate. In other embodiments, gas valve 42 may be a multi-stage or variable-stage (e.g., continuously variable) gas valve. In still further embodiments, a fixed value orifice (with on-off valve) and a variable value orifice (with adjustable valve) may be used together.

TABLE-US-00001 Valve (On/Off) A B BTU Rate On Off 10k BTU Off On 20k BTU On On 30k BTU (Sum of A + B) Orifice: A = 10k BTU B = 20k BTU

[0053] Depending on which orifice 46, 48 is used, or if both are used, the combustion blower 30 speed may also be adjusted. For example, a lower speed may be used for the orifice 46 with a smaller heat output, a medium speed may be used for a larger orifice 48 with a large heat output, and a highest blower speed may be used where both orifices 46, 48 are supplied fuel.

[0054] In another embodiment, the system may comprise an additional limiting orifice 49 may be positioned just prior to the burner 50, and is shown in broken line in FIG. 6. In such example, the limiting orifice 49 may be less than the combined output for the two orifices 46, 48. This allows for a limited maximum output, but which may be retrofitted to a higher maximum output at a later date if desirable, for example if the furnace is going to be installed in a larger sized RV.

TABLE-US-00002 Valve (On/Off) A B BTU Rate On Off 16k BTU Off On 30k BTU On On 35k BTU (limited by orifice) Orifice: A = 16k BTU B = 30k BTU C = 35k BTU

[0055] Referring now to FIG. 3, a second schematic view of the furnace 10 is shown. The view is depicted from an opposite side of the FIG. 1 view. The fuel supply line 36 provides fuel to a burner 50 where a flame is ignited by fuel from the first orifice 46, second orifice 48, or both orifices 46, 48.

[0056] In this view, a heat exchange chamber 35 is shown adjacent to the house blower 20. The heat exchanger 70 (FIG. 4) is shown in broken line in the chamber 35 for clarity but one skilled in the art will recognize that the heat exchanger 70 is a device which is warmed by the combustion flame and over which the house blower 20 moves air before the warmed air moves out of the furnace 10 through ducts 19. The heat exchanger 70 may be, for non-limiting example, a serpentine tube through which a flame passes.

[0057] A burner 50 is depicted in the heat exchange chamber 35 and may be located within the heat exchanger 70 when the heat exchanger 70 is installed. The burner 50 may include one or more igniters 56 which provide a spark or combustion ignition source to the mixture of air and fuel. For example, the igniter(s) 56 may provide a repetitive spark until the fuel/air mixture ignites. Once ignited, the flame is housed within the heat exchanger 70 and the heat exchange chamber 35 warms from the flame within the heat exchanger 70. The house blower 20 moves air through the heat exchange chamber 35 and out of the furnace 10 through one or more ducts 19 (FIG. 1).

[0058] The heat exchanger 70 may have a second end which extends from the heat exchange chamber 35 and allows for exhaust at a combustion exhaust outlet 74 (FIG. 2). While the first and second ends of the heat exchanger 70 are adjacent to one another in the heat exchange chamber 35, alternatively in some embodiments, the first and second ends of the heat exchanger 70 may be located at locations more spaced apart than shown. Further, the heat exchanger 70 may comprise a thermocouple 71 or other temperature sensor located near the exhaust end so that an exhaust temperature may be provided to the controller 80.

[0059] As noted previously, during normal operation of a furnace 10, the thermostat 60 (FIG. 1) has a user input set temperature. When the actual measured temperature is below the set temperature, the furnace 10 is activated to heat the climate controlled passenger compartment 102. When activated, fuel supply line 36 is opened to provide fuel. The combustion blower 30 and the house blower 20 are started to move air to mix with the fuel and the burner 50 is ignited to begin warming the heat exchanger 70 and the heat exchange chamber 35. As the warming starts, the actual temperature changes and the furnace 10 operates until actual temperature of the passenger compartment 102 of the recreational vehicle 100, for example, reaches the set temperature.

[0060] Present embodiments provide one or more additional inputs to control output of the furnace 10, independent of the thermostat 60 temperature and set temperature. In some embodiments, the inputs may be, without limitation, amperage, temperature, pressure, and/or house blower 20 RPM. Any of these inputs may be measured by sensors 28, 29, 31, 34 (FIG. 4) which are located in the envelope or footprint of the furnace 10. This generally means within or connected to the furnace housing 12. By placing the sensors 28, 29, 31, 34 within the furnace housing 12, the sensors 28 are not subject to or dependent upon outside influences such as installation variations, discrepancies, differences in size and layout of the passenger compartment 102 being warmed.

[0061] Referring now to FIG. 4, a further schematic view of the furnace 10 is shown which depicts various sensors 28, 29, 31, and 34 that provide inputs to control the furnace 10 operation, independent of the thermostat 60 which controls set temperature. The furnace 10 is represented by an outline depicting an envelope or footprint of the furnace housing 12.

[0062] Within the furnace housing 12 is a house blower 20, including a schematic representation of the blower wheel 26 and the motor 24. The motor 24 is shown with a representative air flow moving air into a heat exchange chamber 35. Within the heat exchange chamber 35 is the heat exchanger 70, so that heat from the burner 50 is transferred to the air within the heat exchange chamber 35. Extending from the heat exchange chamber 35, and the furnace 10 more generally are one or more ducts 19 which move the warm air throughout the recreational vehicle 100.

[0063] Also depicted are various sensors 28, 29, 31, 34 that are located within the furnace 10. Any of these example sensors 28, 29, 31, 34 may be utilized to provide further input to a controller 80 (FIG. 5). The sensor inputs, 28, 29, 31, 34 may provide operating conditions within the furnace 10, for example at the heat exchanger chamber 35. For example, within the furnace 10, and for example the heat exchange chamber 35, a thermometer 28 is depicted. The thermometer 28 is a temperature sensor that may measure temperature within the heat exchange chamber 35 so that the controller 80 may make a determination, based on conditions within the heat exchange chamber 35. In some embodiments, the thermometer 28 may be located at an exit from the heat exchange chamber 35, such as a duct 19 inlet. For example, if the temperature is above a preselected value this may represent that there is a restriction downstream in the one or more ducts 19 or alternatively in the intake between the room and the house blower 20.

[0064] Also shown within the heat exchange chamber 35 may be a pressure measuring sensor 34. The pressure sensor 34 may provide a pressure measure within the heat exchange chamber 35. Increased air pressure may also indicate a blockage of air flow downstream of the furnace 10, within the one or more ducts 19 (FIG. 1) for example.

[0065] Likewise, a further sensor 29 is shown at the house blower motor 24. The sensor 29 measures current of the house blower 20, which may be reported to the controller 80. With data from any of these example sensors 28, 29, 31, 34 the controller 80 may make determinations about the amount of heat output by the furnace 10, and make adjustments which are independent of the thermostat 60 settings. When there is a restriction, the blower may spin easier, resulting on reduced current even though the RPMs increase.

[0066] An additional sensor 31 may be utilized to measure house blower motor 24 revolutions per minute (RPM). The RPM may also increase as a result of a restriction in a duct 19 or at a connection between the duct 19 and the heat exchange chamber 35.

[0067] Further, the instant furnace may comprise an air proving switch in the blower housing 22. It is desirable to provide a safety feature such that combustion blower 30 must be operating if furnace gas is directed to the burner 50. Accordingly, to some embodiments, a switch 66 may be located in the housing 22 wherein the combustion blower 30 is located, or at a location close to such blower where air flow from such blower 30 may be detected. In some embodiments, the switch may be a sail switch and in some embodiments, the switch may be a hall effect sensor. These switches 66 may be used to prove or satisfy to the furnace controller 80 that the combustion blower 30 is on and moving air before allowing the gas burner 50 is turned on. Likewise, if the combustion blower 30 fails, the controller 80 will recognize by the switch of the change in air flow from the combustion fan and the gas burner 50 can be cut off.

[0068] In some embodiments, the sail switch may form two contacts of a microswitch and sail that moves between an open position, when the combustion blower 30 is not running, and a closed position, when the combustion blower 30 is operating causing air flow to close the sail switch.

[0069] In some embodiments, the switch 66 may be a Hall Effect sensor 67. As opposed to a sail arrangement that responds to air movement, the Hall Effect sensor 67 may comprise a sensor 67 and two magnets on the combustion blower 30 or motor 24 which passes the sensor 67. When the moving magnet passes the fixed magnet, a signal is created. The Hall Effect switch may measure the RPM of the combustion blower 30 or a motor driving such blower 30. Measuring the RPM directly relates air flow to the burner, such that when the blower 30 is rotating, the air flow has to move to the burner 50. As between the two switch types, the Hall Effect 67 has no moving parts and is solid state, so it has a lower likelihood of failure. On the other hand, dust, dirt, or debris could stay on the sail switch and result in the switch being closed inappropriately. The Hall Effect sensor 67 is also designed to work in specific ranges of RPMs. It will not make electrical contact below a minimum RPM and will open contacts above a maximum RPM. This could be relevant if the house blower 20 wheel is damaged, and the RPM of the motor 24 can increase. A sail switch would continue to be engaged, whereas the Hall Effect sensor 67 would open and shut off the burner 50.

[0070] Additionally, it should be understood that physical restrictions are not the sole cause of sensor readings or measurements which may be out of desired or expected specification. Various operating conditions may result in sensor readings that further result in a change in operating condition of the furnace 10. For example, the furnace 10 may be installed with excessive duct 19 length that creates inherent restriction due to the excessive duct length, rather than a physical restriction. In another situation, the furnace 10 may be installed with too few ducts 19 to operate properly. This creates a restriction due to insufficient ducting. Still further, a register may be blocked by a box or a pet. In still another example, a duct 19 may be collapsed defining a physical restriction, either by installation or some other action that creates the damage.

[0071] Below the furnace 10, a thermostat 60 is shown that represents a user interface and which comprises a display temperature. Thermostat 60 may display either or both of the actual temperature and the set temperature of the furnace 10. The thermostat 60 may be wirelessly connected or connected by one or more wires to a controller 80 for the furnace 10. The thermostat 60 may also include a display, buttons, a microphone, a speaker, or other components to communicate with the user. Additionally, the thermostat 60 may include a processor 84 and memory 86 configured to receive user-determined parameters such as, for example, a relative humidity of the passenger compartment 102 and to calculate operational parameters of furnace 10 or other HVAC system of the RV 100 as disclosed herein.

[0072] Referring now to FIG. 5, the furnace 10 comprises a controller 80. The controller 80 may be mounted on the furnace 10, on the thermostat 60, or at an alternate location remote from either. The controller 80 (computing device) may be an electronic control unit (ECU), a central processing unit (CPU), and/or the like and may be defined by one or more controllers. The controller 80 may comprise a printed circuit board (PCB) 82, at least one processor 84, at least one memory 86, and/or other component(s) of computing device(s). In some embodiments, the controller 80 may comprise one or more circuit boards 82, which may be individually connected to individual furnace components or which may be connected to two or more of the furnace components. The controller 80 may comprise a primary board and a daughter board for control of certain features. Each circuit board 82 may comprise one or more modules for control. The controller 80 may be configured to control operation of the various components of the furnace 10 such as, for example, house blower 20, combustion blower 30, gas valves 42, burner igniter 56, and sensors 28, 29, 31, 34 to regulate the environment of the passenger compartment 102 in the recreational vehicle 100.

[0073] The controller 80 may also receive inputs from the thermostat 60 and one or more of the sensors 28, 29, 31, 34. The controller 80 may be provided at any suitable location within recreational vehicle 100, and may be operably coupled (e.g., electrically or wirelessly coupled) to the furnace 10. Further, controller 80 may be operably coupled to thermostat 60 (FIG. 4), which provides a user interface for the furnace 10, as well as advises the users of the temperature and other characteristics of the climate controlled passenger compartment 102 within the recreational vehicle 100.

[0074] The controller 80 may include a combination of hardware and software components. Although illustrated as one controller, the single controller 80 may comprise more than one controller to control the components of the furnace 10. Each controller 80 may include a printed circuit board (PCB) 82 that is populated with a plurality of electrical and electronic components that provide power, operational control, and/or protection to the furnace, or fluid heating system, 10.

[0075] The PCB 82 may for example comprise an electronic processor 84 (for example, a microprocessor, a microcontroller, or another suitable programmable device or combination of programmable devices), a memory 86, and a bus 88, such as a controller-area network bus (CAN bus). In some embodiments, the circuit board 82 may comprise a second circuit board. For example, the first board may control some functions and the second board may control other functions.

[0076] The bus 88 connects various components of the PCB 82, such as the memory 86 to the electronic processor 84. The memory 86 includes, for example, a read-only memory (ROM), a random access memory (RAM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a hard disk, or another suitable magnetic, optical, physical, or electronic memory device. The electronic processor 84 may be connected to the memory 86 and executes software instructions that are capable of being stored in the RAM 86 (for example, during execution), the ROM (for example, on a permanent basis), or another non-transitory computer readable medium such as another memory or disc. Additionally, or alternatively, the memory 86 is included in the electronic processor 84. In some embodiments the memory 86 may comprise one or more non-transitory computer readable storage media storing computer instructions executable by one or more processors 84 to perform any of the aforementioned methods. Some embodiments also include a computer program product including instructions executable by one or more processors 84 to perform any of the aforementioned methods. Software included in the implementation of the furnace or fluid heating system 10 is stored in the memory 86 of the respective controller 80 that it pertains to. The software includes, for example, firmware, one or more applications, program data, one or more program modules, and other executable instructions. The controllers 80 are configured to retrieve from the memory 86 and execute, among other things, instructions related to the control processes and methods described herein. In some embodiments, reference to encoded software may encompass one or more applications, bytecode, one or more computer programs, one or more executables, one or more instructions, logic, machine code, one or more scripts, or source code, and vice versa, where appropriate, that have been stored or encoded in a computer-readable storage medium. In particular embodiments, encoded software includes one or more application programming interfaces (APIs) stored or encoded in a computer-readable storage medium. Particular embodiments may use any suitable encoded software written or otherwise expressed in any suitable programming language or combination of programming languages stored or encoded in any suitable type or number of computer-readable storage media. In particular embodiments, encoded software may be expressed as source code or object code. In particular embodiments, encoded software is expressed in a higher-level programming language, such as, for example, C, Python, Java, or a suitable extension thereof. In particular embodiments, encoded software is expressed in a lower-level programming language, such as assembly language (or machine code). In particular embodiments, encoded software is expressed in JAVA. In particular embodiments, encoded software is expressed in Hyper Text Markup Language (HTML), Extensible Markup Language (XML), or other suitable markup language.

[0077] In some embodiments, controller 80 includes one or more memory devices 86 and one or more processors 84. The processors 84 can be any combination of general or special purpose processors, CPUs, or the like that can execute programming instructions or control code associated with operation of recreational vehicle 100. The memory devices 86 (i.e., memory) may represent random access memory such as DRAM or read only memory such as ROM or FLASH. In one embodiment, the processor 84 executes programming instructions stored in memory. The memory 86 may be a separate component from the processor 84 or may be included onboard within the processor 84. The one or more memory devices 86 may be store data, for example lookup table(s) relating to any or all of fuel supply, valves, orifices, burner, which may be used to make determinations of which valve and orifice will be selected. Alternatively, controller 80 may be constructed without using a processor, for example, using a combination of discrete analog or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

[0078] In certain embodiments, controller 80 includes a network interface 88 such that controller 80 can connect to and communicate over one or more wireless networks with one or more network nodes. Controller 80 can also include one or more transmitting, receiving, or transceiving components for transmitting/receiving communications with other devices communicatively coupled with the recreational vehicle 100. Additionally, or alternatively, one or more transmitting, receiving, or transceiving components can be located off board the controller 80.

[0079] The PCB 82 of each controller 80 may also comprise, among other things, a plurality of additional passive and active components such as resistors, capacitors, inductors, integrated circuits, converters, and amplifiers. These components are arranged and connected to provide a plurality of electrical functions to the PCB 82 including, among other things, filtering, signal conditioning, signal converter, and voltage regulation.

[0080] Each controller 80 may also include an input/output (I/O) system 90 that includes routines for transferring information between components within the controller 80 and/or other components of the furnace 10. The I/O system 90 may include a wireless receiver/transmitter for wireless communicating with other controllers and/or an external device. In some embodiments, each controller 80 receives power from a power supply (for example, an input power). The input power may be, for example, a main power supply, a battery source, for example, AA batteries, AAA batteries, etc., solar panels, thermo-electric generators (TEG), or a wall power adapter.

[0081] The controller 80 may be an integrated controller or a distributed controller that directs operation of HVAC system 10 of RV 100. The controller 80 includes an interface to receive, for example, thermostat calls, temperature setpoints, blower control signals, environmental conditions, and operating mode status for various zones of the RV 100. The environmental conditions may include indoor temperature and relative humidity of the passenger compartment 102. In a typical embodiment, the controller 80 also includes a processor 84 and a memory 86 to direct operation of the HVAC system 10 of RV 100 including, for example, a speed of the house blower 20.

[0082] Still referring to FIG. 5, in some embodiments, the plurality of sensors 28, 29, 31 34 are associated with controller 80 (FIG. 5). The plurality of sensors 28, 29, 31, 34 provide environmental information within the envelope or footprint of the furnace 10. The plurality of sensors 28, 29, 31, 34 may also send the environmental information to the controller 80 for determinations by the controller 80 of furnace 10 operating conditions. These determinations may be independent of thermostat 60 which may sense a temperature in the recreational vehicle 100. In some embodiments, the thermostat 60 provides additional functions such as, for example, operational, diagnostic, status message display, and a visual interface that allows at least one of an installer, a user, a support entity, and/or a service provider to perform actions with respect to the furnace 10 of RV 100. In some embodiments, the controller 80 may for example be located in the housing of the thermostat 60 so that the plurality of sensors report information to the controller 80 at such location. In such embodiments, the thermostat 60 may receive input from at least one sensor of the plurality of environment sensors 28, 29, 31, 34 to determine the environmental condition information and communicate that information to the user, for example for troubleshooting or during normal operating conditions.

[0083] Whether on-board the furnace or on-board the thermostat, the controller 80 may also receive input from the thermostat 60.

[0084] The controller 80 may be electrically connected to the various components of the furnace 10. For example, the controller 80 may be connected to: a valve which controls fuel flow to the one or more orifices 46, 48, the house blower 20 and the combustion blower 30, the igniter 56 for the burner 50, the thermostat 60, and the one or more sensors 28, 29, 34.

[0085] Depending on the embodiment, certain acts, events, or functions of any of the algorithms described herein can be performed in a different sequence, can be added, merged, or left out altogether (e.g., not all described acts or events are necessary for the practice of the algorithms). Moreover, in certain embodiments, acts or events can be performed concurrently, e.g., through multi-threaded processing, interrupt processing, or multiple processors or processor cores or on other parallel architectures, rather than sequentially. Although certain computer-implemented tasks are described as being performed by a particular entity, other embodiments are possible in which these tasks are performed by a different entity.

[0086] In some embodiments, a communication device 94 (FIG. 1) may be provided for communication with the controller 80, directly or indirectly, for input to the furnace 10. For example, such communication device 94 include mobile-computing devices configured to interact with the furnace 10 to monitor and modify at least some of operating parameters of the furnace 10. Mobile computing devices may be, for example, a personal computer (e.g., desktop or laptop), a tablet computer, a mobile device (e.g., smart phone), and the like. In a typical embodiment, communication device 94 includes at least one processor, memory, and a user interface such as a display. One skilled in the art will also understand that communication device 94 disclosed herein includes other components that are typically included in such devices including, for example, a power supply, a communications interface, and the like.

[0087] In some embodiments, the sensors 28, 29, 31, 34 may comprise one or more temperature sensors. The temperature may be taken in the heat exchanger 70, or in the heat exchange chamber 35 by temperature sensor, or thermometer, 28. By taking a temperature in this area, when a furnace 10 is operating, if the temperature is too high, the determination may be made to reduce the output of the fuel orifices 46, 48. Alternatively, if the temperature is consistently low, the determination may be made to use a second or both orifices 46, 48, or otherwise increase fuel supply to increased output. In some embodiments, the temperature may be taken near an exit to the chamber 35, such as at a duct 19 inlet.

[0088] Likewise, combustion blower 30 and house blower 20 changes may be made dependent upon the temperature changes. With increased heat, the combustion fan speed may be increased, and alternately, with decreased heat, the combustion fan speed may be decreased.

[0089] In another embodiment, pressure may be measured by a pressure sensor 34 in the heat exchange chamber 35. Increased pressure may indicate a restriction in a duct 19. Therefore, it may be desirable to decrease heat output of the furnace 10. Alternatively, the pressure may be low which indicates that heat output may be increased or that there is a leak in the system.

[0090] Still further, another input may be amperage of the house blower 20. Generally, when the amperage of the house blower motor 24 decreases, this may indicate a restriction of a duct 19 (FIG. 1). Likewise, when there is a duct restriction, the fan RPMs may increase. Alternately, when the RPMs are within a specific range, this may be indicative of a good heating condition.

[0091] Based on the sensor readings and independent of the temperature reading of the thermostat 60 associated with the furnace 10, operating conditions may be varied. In some embodiments, a self-adjusting method of adjustment may be developed that utilizes data from previous heating events and the current heating event. This method may sense a restriction and lower the heat output, but also sense a reduction in restriction and increase the heat output. Effectively, this method may be considered an actively learning system.

[0092] In another method of operation, for a given number of starts, start the furnace at High output, monitor the sensors, reduce to Medium or Low as needed. The controller 80 collect data from these first starts to determine the level that the furnace 10 will start in the future and compare the start data to subsequent starts to determine if there is a restriction. If a restriction determination is made, this option would require a reset back to a factory state once a restriction in the system is resolved.

[0093] In still a further embodiment, and most simply, the furnace may always start at High heat output and monitor sensors to reduce to Medium or Low heat output as needed.

[0094] Additionally, the thermostat 60 may cause change in operation via the controller 80. For example, as the room temperature approaches the set temperature, as detected by the thermostat, changes in operation may be made. In some embodiments, the rate of temperature change during warming may be altered to slow or feather the rate of temperature increase. This may be done by changing the valve or combination of valves, or the fan speed, or a combination of these components to slow the temperature climb as the actual temperature approaches the set temperature.

[0095] While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the invent of embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

[0096] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. The indefinite articles a and an, as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean at least one. The phrase and/or, as used herein in the specification and in the claims, should be understood to mean either or both of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases.

[0097] Multiple elements listed with and/or should be construed in the same fashion, i.e., one or more of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the and/or clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to A and/or B, when used in conjunction with open-ended language such as comprising can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0098] As used herein in the specification and in the claims, or should be understood to have the same meaning as and/or as defined above. For example, when separating items in a list, or or and/or shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as only one of or exactly one of, or, when used in the claims, consisting of, will refer to the inclusion of exactly one element of a number or list of elements. In general, the term or as used herein shall only be interpreted as indicating exclusive alternatives (i.e. one or the other but not both) when preceded by terms of exclusivity, such as either, one of, only one of, or exactly one of. Consisting essentially of, when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0099] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term about. Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently-disclosed subject matter.

[0100] As used herein, the term about, when referring to a value or to an amount of mass, weight, time, volume, concentration or percentage is meant to encompass variations of in some embodiments 20%, in some embodiments 10%, in some embodiments 5%, in some embodiments 1%, in some embodiments 0.5%, and in some embodiments 0.1% from the specified amount, as such variations are appropriate to perform the disclosed method.

[0101] As used herein, ranges can be expressed as from about one particular value, and/or to about another particular value. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as about that particular value in addition to the value itself. For example, if the value 10 is disclosed, then about 10 is also disclosed. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0102] As used herein in the specification and in the claims, the phrase at least one, in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase at least one refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, at least one of A and B (or, equivalently, at least one of A or B, or, equivalently at least one of A and/or B) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0103] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0104] In the claims, as well as in the specification above, all transitional phrases such as comprising, including, carrying, having, containing, involving, holding, composed of, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases consisting of and consisting essentially of shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures.

[0105] Certain terminology is used in the following description for convenience only and is not limiting. The words right, left, top, and bottom designate directions in the drawings to which reference is made. The words a and one are defined as including one or more of the referenced item unless specifically stated otherwise. This terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. The phrase at least one followed by a list of two or more items, such as A, B, or C, means any individual one of A, B or C as well as any combination thereof.

[0106] The foregoing description of methods and embodiments has been presented for purposes of illustration. It is not intended to be exhaustive or to limit the invention to the precise steps and/or forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention and all equivalents be defined by the claims appended hereto.