HEAT PUMP SYSTEM WITH COMBUSTION HEATING

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to U.S. patent application Ser. No. 18/965,871, entitled “HYBRID HEATING SYSTEM WITH HUMIDITY CONTROL,” filed on Dec. 2, 2024, which is hereby incorporated by reference herein in its entirety for all purposes.

BACKGROUND

This disclosure generally relates to hybrid heating systems and, not by way of limitation, controlling two independent heating modalities for a building.

Hybrid heating system may include two heat sources, where a gas furnace is used to preheat for a heat pump. Heat pumps become inefficient at freezing temperatures. A heat pump can both heat and cool a building very efficiently but have a flaw with heating in cold temperatures. Hybrid heating is mostly used at places where heating with one heat source does not work through all temperatures efficiently.

SUMMARY

Embodiments described herein are generally related to systems and methods for operating a hybrid heating system for the heating of a building is disclosed using two independent heaters. A heat pump transfers heat to the input airstream upstream from a furnace that is controlled to add supplemental heat. A bypass mechanism directs airflow to avoid the furnace when it is not in operation to rely on the heat pump alone. The indoor coil of the heat pump is upstream of the furnace. Controlling both modes of heating for the building allows both to contribute in heating the airstream through the hybrid heating system.

In one embodiment, a heating system with hybrid heating to control the heating of a building is disclosed. The heating system comprises a heat pump, a furnace and a diverter. The heat pump comprising an indoor coil for exchanging heat with an airstream. The furnace is positioned downstream to the indoor coil, and transfers heat to the airstream when operating. The diverter selectively redirects the airstream away from the furnace when the furnace is not operating.

In another embodiment, a heating apparatus for hybrid heating to control the heating of a building is disclosed. The heating apparatus comprises an air intake, a heat pump, a furnace, a plurality of temperature sensors, and a control unit. The heat pump includes an indoor coil for exchanging heat downstream from the air intake. The furnace is downstream to the indoor coil in air communication with the indoor coil. The plurality of temperature sensors measures temperature both upstream and downstream of the indoor coil. The control unit modulates heating from the heat pump and the furnace.

In yet another embodiment, a heating method using hybrid heating system for controlling heating of a building is disclosed. A plurality of temperatures of the hybrid heating system are monitored using a plurality of temperature sensors. An indoor coil that is part of a heat pump is used to exchange heat. The plurality of temperature sensors include a first temperature sensor upstream of the indoor coil, and a second temperature sensor downstream of the indoor coil. Air is warmed during a heating operation with a furnace that is positioned downstream to the indoor coil, and in fluidic communication with the indoor coil. The furnace heating is modulated with a control unit.

Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating various embodiments, are intended for purposes of illustration only and are not intended to necessarily limit the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is described in conjunction with the appended figures:

FIG. 1A shows indoor and outdoor units with their placement for a building;

FIGS. 1B-1C illustrate schematic views of the hybrid heating system;

FIG. 2A illustrates top view of a hybrid heating system;

FIGS. 2B-2C illustrate side views of a hybrid heating system;

FIGS. 3A-E illustrate schematic views of an indoor unit with diversion capability;

FIGS. 4A-F illustrate charts of a breakdown of usage of the various modes of heating in the hybrid heating system;

FIG. 5 illustrates a method for controlling heat and comfort of a building with the hybrid heating system; and

FIG. 6 illustrates a method for controlling heat and comfort of a building with the hybrid heating system.

In the appended figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a second alphabetical label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

DETAILED DESCRIPTION

The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment. It is understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims.

Referring initially to FIG. 1A, a schematic view of a hybrid heating system 100 according to an embodiment is shown. The hybrid heating system 100 shows a building or house 103, and a heat pump & furnace divided between an indoor unit (IDU) 120 and an outdoor unit (ODU) 118. A thermostat 138 is connected to the IDU 120 to provide a control interface and remote sensors to allow control of the hybrid heating system 100 according to occupant preferences.

The hybrid heating system 100 provides two-source heating for the house 103 with humidity control. The outdoor temperature and humidity levels play an important role in determining the operation of the hybrid heating. When these conditions are not favorable, the hybrid heating system 100 may switch to combustion gas heat (or another secondary source) to maintain efficiency and comfort. The ODU 118 includes an ODU fan 102, a heat exchanger coil 106, and a compressor 104. The ODU fan 102 is configured to draw outside ambient air into the ODU 118. The ODU fan 102 ensures a continuous and regulated airflow over the heat exchanger coil 106, thereby facilitating heat exchange.

The heat exchanger coil 106 is disposed within an airflow path created by the ODU fan 102 in airflow communication with an ODU intake 124 of the ODU 118. In heating mode, the heat exchanger coil 106 functions to absorb heat from the air drawn in by the ODU fan 102, thereby heating the refrigerant passing through the heat exchanger coil 106. The heat exchanger coil 106 is airflow connected to the compressor 104. The compressor 104 is configured to compress the refrigerant, thereby raising the temperature and pressure of the refrigerant. The high-pressure refrigerant is then directed to the IDU 120, specifically to a indoor coil 108.

The IDU 120 includes the indoor coil 108, a control unit 116, and an air exit 136 to condition the building 103. In heating mode for the hybrid heating system 100, the high-pressure refrigerant from the compressor 104 is directed to the indoor coil 108, where it releases its absorbed heat to the air passing over the indoor coil 108. A fan (not shown) is positioned downstream of the indoor coil 108. The air exit 136 circulates the heated air throughout the building 103, ensuring even distribution of warm air to maintain consistent indoor comfort.

The control unit 116 is configured to receive data from temperature and humidity sensors in the ODU 118, IDU 120 and any thermostat(s) in the building 103 or thermostat 138 to control operation of the hybrid heating system 100 to achieve a desired comfort programmed by occupants. Furthermore, the control unit 116 also executes a control algorithm to switch amongst multiple heaters of the hybrid heating system 100 through activation of diversion baffles in the air flow of the IDU 120.

A coefficient of performance (COP) is a measure of a heat pump's efficiency. It is the ratio of heating or cooling provided to the energy consumed. The COP of a heat pump is influenced by the outdoor temperature and humidity. When the outdoor temperature drops, the heat pump works harder to extract heat from the colder air, which lowers its COP. Conversely, when the outdoor temperature is higher, the heat pump operates more efficiently, resulting in a higher COP.

Similarly, high humidity levels can also affect the efficiency of the heat pump. Moist air requires more energy to heat or cool, which can reduce the COP. These changes in COP directly impact the decision-making process for the IDU 120. When the COP of the heat pump drops below a certain threshold (due to low outdoor temperatures and/or high humidity), it becomes less efficient to use the heat pump. At this point, the hybrid heating system 100 may decide to switch to gas heat, which can be more efficient under these conditions. The hybrid heating system 100 continuously monitors the outdoor conditions and adjusts the operation of the heat pump and gas heat accordingly. This ensures efficiency and comfort inside the house 103.

Referring initially to FIG. 1B, a schematic view of a hybrid heating system 100-1 according to an embodiment of the present disclosure is illustrated. The hybrid heating system 100-1 has a heat pump and an auxiliary heat source such as a furnace 128 that work together to provide efficient heating solutions for various environmental conditions. Furnace 128 can boost the heating beyond the heat pump or be inactive with the airflow diverted around the furnace 128. In this embodiment, furnace 128 is boosting the heating with a diverter 150 sending airflow to furnace 128.

Typically, the heat pump has components divided between the ODU 118 and the IDU 120-1. Heat pumps can cool or heat building 103, but for the purposes of this disclosure we describe operation in heating mode. For the hybrid heating system 100, IDU 120 includes a heater, for example, a gas furnace 128 as a separate assembly or integrated into a unitary enclosure. In the ODU 118, the heat pump uses an ODU fan 102 for circulating ambient air, the compressor 104 increases refrigerant pressure, the heat exchanger coil 106 absorbs heat, an expansion valve 110 regulating refrigerant flow and reducing pressure, and a four way valve 115 for switching between heating mode and cooling mode of the heat pump. The IDU 120 includes a indoor coil 108 to release heat, an IDU fan 114 or blower fan for air circulation, a control unit 116 for operational management of both the IDU 120 and ODU 118.

The various components of the heat pump work in concert with furnace 128 to transfer and manage heat between an ODU 118 and an IDU 120 of the hybrid heating system 100-1. Multiple sensors monitor temperature and humidity in various locations of the hybrid heating system 100 to allow determining indoor temperature/humidity, outdoor temperature/humidity. Through analysis of sensor information things such as dew point can be determined to avoid condensation in furnace 128, or modulating heating from the heat pump and/or furnace according to efficiency, cost, and other factors.

The ODU 118 comprises an outdoor sensor block 122, the ODU fan 102, the heat exchanger coil 106, the compressor 104, the expansion valve 110, and the four-way valve 115. The outdoor sensor block 122 is positioned at an ODU intake 124 of the ODU 118. The outdoor sensor block 122 comprises an outdoor temperature sensor 122a and an outdoor humidity sensor 122b in air communication with the outdoor ambient air from the ODU intake 124. The outdoor temperature sensor 122a is configured to measure temperature of outdoor air while the outdoor humidity sensor 122b is configured to measure humidity of the outdoor air.

The data collected by the outdoor temperature sensor 122a and the outdoor humidity sensor 122b are transmitted to control unit 116 to facilitate the efficient operation of the hybrid heating system 100-1. The ODU fan 102 is positioned to force outside air over the outdoor sensor block 122 and h coil 106. The ODU fan 102 draws outside air into the ODU 118 to ensure a continuous and regulated airflow over the heat exchanger coil 106, thereby facilitating heat exchange with the outside air. Knowing the outdoor temperature and humidity allows efficiently modulating heat pump and furnace heating modalities in the IDU 120.

The heat exchanger coil 106 is placed within an airflow path created by the ODU fan 102 in airflow communication with the ODU intake 124. In heating mode, the heat exchanger coil 106 functions to absorb heat from the air drawn in by the ODU fan 102, thereby heating the refrigerant passing through the heat exchanger coil 106. The heat exchanger coil 106 is fluidly connected to the compressor 104 via a refrigerant line 112 running through the four-way valve 115.

Compressor 104 is coupled with the expansion valve 110 and the heat exchanger coil 106 through the four-way valve 115. The compressor 104 is configured to compress the refrigerant, thereby raising the temperature and pressure of the refrigerant. The high-pressure refrigerant is then directed through the refrigerant line 112 to the IDU 120 by way of the four-way valve 115, specifically to the indoor coil 108.

The expansion valve 110 is coupled with the indoor coil 108 in a refrigerant circuit through a refrigerant line 112 from the IDU 120 within building 103. The expansion valve 110 is configured to reduce the pressure of the refrigerant before it re-enters the heat exchanger coil 106. This pressure reduction causes the refrigerant to cool, enabling it to absorb heat from the intake airflow 124 passing over the heat exchanger coil 106.

The IDU 120-1 includes furnace 128, an upstream sensor block 123, a midstream sensor block 125, the indoor coil 108, the IDU fan 114, the control unit 116, and a downstream sensor block 130. In this embodiment, furnace 128 is integrated into the same enclosure of the IDU 120 as the heat pump and diverter 150, but in other embodiments, the furnace 128 can be a separate unit air coupled with the remainder of the IDU 120. The downstream sensor block 130 includes a downstream temperature sensor 130a and a downstream humidity sensor 130b.

The upstream sensor block 123 measures the temperature and humidity of the return air 135 entering the IDU 120-1. Furnace 128 is in upstream air communication with indoor coil 108 of the heat pump. In other words, furnace 128 is located downstream of the return air inlet 135 and is upstream of the indoor coil 108 within the IDU 120-1 in this embodiment. Furnace 128 serves as an auxiliary heat source, configured to activate when the heat pump alone cannot achieve the desired temperature efficiently, or to modify humidity levels for the desired comfort. Furnace 128 includes a combustion chamber 134 and a heat exchanger 132 that transfers heat to the airflow when activated. The midstream sensor block 125 includes a midstream temperature sensor 125a and a midstream humidity sensor 125b. Measuring temperature and humidity after any changes introduced by the furnace 128 is done by the midstream sensor block 125.

In this embodiment, furnace 128 is used in addition to the heat pump to pre-heat the airflow in a boost mode enabled by the diverter 150. Other embodiments can divert airflow around the furnace 128 partially or fully to rely more on the heat pump for heating in the bypass mode. When the heat pump is cooling, the diverter 150 can take the furnace out of the air path.

The indoor coil 108 is positioned downstream of the furnace 128 in this embodiment. In heating mode for the hybrid heating system 100-1, the high-pressure refrigerant from the compressor 104 is directed to the indoor coil 108, where it releases its absorbed heat to airflow passing over the indoor coil 108. The indoor coil 108 is fluidly connected to the expansion valve 110 and four-way valve 115 in the ODU 118 via refrigerant lines 112.

Control unit 116 is located within the IDU 120-1, but could be in the ODU 118 in other embodiments. The control unit 116 is electronically coupled to the outdoor sensor block 122, the upstream sensor block 123, the downstream sensor block 130, the midstream sensor block 125, the furnace 128, the diverter 150, the four way valve 115, the compressor 104, and other components in the hybrid heating system 100. Control unit 116 is configured to receive data from the upstream and downstream temperature and humidity sensors and controls operation of the heat pump and the furnace 128 to achieve a desired temperature and humidity downstream in the building 103. The control unit 116 further determines if the downstream humidity sensor 130b is reading outside of a desired humidity downstream to modulates heating operation of the heat pump and/or the furnace 126, the diverter 150, and the IDU fan 114 to achieve the desired humidity downstream for the desired temperature for the supply air 136 or as measured by the thermostat 138.

In an example, the control unit 116 monitors the readings from the outdoor, upstream, midstream, and/or downstream sensor blocks 122, 123, 125, 130. For instance, during a particularly cold winter day, the outdoor sensor block 122 detects ambient air at a temperature of 23° F. (−5° C.) and humidity level of 70%. The indoor coil 108 of the heat pump, situated downstream of the furnace 128, initially operates to transfer heat from the outdoor air to the indoor environment. However, as the outdoor temperature remains extremely low, the control unit 116 determines that the heat pump alone may not suffice to maintain the desired indoor temperature of 72° F. (22° C.).

The downstream temperature sensor 130a measures the temperature of the supply air 136 exiting the hybrid heating system 100-1, which initially reads 64° F. (18° C.). The downstream humidity sensor 130b, meanwhile, indicates a relative humidity level of 55%, which is outside the desired range of 40-50% for as set at the thermostat 138. Upon detecting these conditions, the control unit 116 enters a boost mode by activating the furnace 128 and moving the baffle(s) 160 or dampers in the diverter 150 to supplement the heating provided by the heat pump while optionally reducing the power to the heat pump. The furnace 128 preheats the incoming air, which is subsequently further heated by the heat pump so long as the indoor comfort is kept in the desired range set at the thermostat 138. Control unit 116 also controls the fuel feed to the furnace 128 and the flu fan to exhaust the combustion exhaust.

As the hybrid heating system 100-1 continues to operate, the downstream temperature sensor 130a records a gradual increase in the temperature of the supply air 136 exiting the hybrid heating system 100-1, approaching the desired 72° F. (22° C.). However, the downstream humidity sensor 130b still reports a humidity level of 55% in this example. Recognizing that the humidity is still outside the optimal range, the control unit 116 modulates the operation of the heat pump and furnace 128 relative to each other while optionally moving the baffles 160 to maintain the desired temperature, but modulate the humidity. The control unit 116 may also adjust the speed of the IDU fan 114 to change over the air in the building 103 faster or slower. In an alternative embodiment, baffles are not used to divert around the furnace such that the airflow passes always passes through the furnace 128 and heat exchanger.

Eventually, the downstream humidity sensor 130b records a decrease in the relative humidity to 47%, which falls within the desired range. The control unit 116 ensures that the furnace 128 and heat pump operate in concert to maintain both the target temperature of 72° F. (22° C.) and the desired humidity level. By continuously adjusting the operations based on real-time sensor data, the control unit 116 effectively maintains a comfortable indoor environment while optimizing energy efficiency. This dynamic modulation showcases the advanced capabilities of the hybrid heating system 100-1 in managing varying climatic conditions measured at the IDU intake 124 and in return air 135 to maintain desired indoor comfort levels.

The thermostat 138 can be used to set the desired temperature and humidity by an occupant. By modulating the heating sources against ambient and intake conditions, there are some changes that can be made to humidity too. Some embodiments may also include a humidifier or dehumidifier that can also be controlled by thermostat 138. The control unit 116 and/or thermostat 138 could control the humidifier/dehumidifier in concert with the heating sources and baffles 160 of the hybrid heating system 100. The baffles are used to switch between heating and cooling modes for the hybrid heating system 100.

In some embodiments, the control unit 116 is configured to modulate the heating operation of the heat pump by varying speeds of the compressor 104 and/or the ODU fan. For instance, during milder winter conditions where moderate heating is required, control unit 116 may reduce the speed of the compressor 104 and/or ODU fan 102. This adjustment decreases the heating capacity of the heat pump, allowing it to operate at lower energy consumption levels if still maintaining indoor comfort set at the thermostat 138. By slowing down these components, the hybrid heating system 100 effectively matches heating output to the current demand.

Conversely, in colder weather scenarios when greater heating capacity is necessary, the control unit 116 can increase the speed of both the compressor 104 and ODU fan 102. This higher speed moves more heat with the heat pump enabling move more warmth to effectively counteract the colder temperature in the building 103. By dynamically adjusting these parameters based on real-time temperature and humidity readings from sensors, the hybrid heating system 100-1 maintains control over indoor climate conditions. The adaptive modulation of heating operations with the heat pump exemplifies the hybrid heating system's 100-1 capability to respond intelligently to varying environmental conditions while the furnace 128 is disabled.

In some embodiments, the control unit 116 is further configured to execute a control algorithm to switch amongst multiple heaters of the hybrid heating system 100-1. Selection of the heaters and the mix of them considers various factors such as grid pricing, grid power availability, speed to target temperature, and time-of-day cost of electricity versus combustion fuels. The hybrid heating system 100 allows user-selectable modes including, but not limited to: electric only, combustion only, cheapest fuel, and/or humidity comfort. Internal and external temperature and humidity sensors are utilized to manage and optimize these modes. Different combustible fuels include, natural gas, methane, propane, diesel, kerosine, heating oil, coal, wood, wood pellets, etc.

For example, in the “electric only” mode, the hybrid heating system 100 uses the heat pump alone relying on electricity to provide heating. This mode is particularly useful when electricity rates are low or when renewable energy sources, such as solar panels, are available.

Conversely, the “combustion only” mode activates only the furnace 128, making it ideal for situations where combustibles such as natural gas is more economical or in instances where electricity supply might be limited due to grid constraints or power outages.

By giving users, the ability to choose a cost effective fuel mode, the hybrid heating system 100 can dynamically switch between electric only and combustion only based on real-time cost data, ensuring that heating is provided at the lowest possible cost. Real time cost data can be provided by the local utilities to the control unit 116.

The “humidity comfort” mode leverages indoor and outdoor humidity sensors 122b,123b,125b,130b to maintain optimal indoor humidity levels in addition to temperature. This mode is beneficial in climates with fluctuating or uncomfortable ambient humidity, as it ensures a comfortable indoor environment by adjusting the operation of the heat pump and furnace accordingly. Different heating sources have unique affect on humidity levels. Models of each heating source would allow mixing between the them to have the desired humidity levels.

The various algorithms are managed by the control unit 116 also includes a “speed to target temp” mode, which adjusts heating operations to reach the desired temperature as quickly as possible, balancing efficiency and speed. This versatile control system enables users to tailor their heating preferences to their specific needs, providing a customizable and efficient solution for maintaining indoor comfort. The control unit 116 has software to support different configurations and modes with models to allow proper control.

The IDU fan 114 is positioned downstream of the indoor coil 108 and furnace in this embodiment. The IDU fan 114 is configured to circulate the heated air throughout the building 103, ensuring even distribution of warm air to maintain consistent indoor comfort. Other embodiments could have the IDU fan 114 before or after the furnace 128 or indoor coil 108.

The downstream sensor block 130 is located at an exit where the supply air 136 leaves the IDU 120 of the hybrid heating system 100-1. The downstream temperature sensor 130a is configured to measure the temperature of the supply air 136 exiting the hybrid heating system 100-1, while the downstream humidity sensor 130b is configured to measure the humidity of the air exiting the hybrid heating system 100-1. The data collected by the downstream temperature sensor 130a and the downstream humidity sensor 130b sensor is transmitted to the control unit 116 to facilitate the efficient operation of the hybrid heating system 100-1.

In some embodiments, the furnace 128 is activated upon operating the heat pump at a maximum heating capacity. For instance, during extremely cold weather conditions where the heat pump 108 alone may struggle to meet the heating demand efficiently, the hybrid heating system 100-1 automatically engages the furnace 128 to supplement heating output. This activation occurs based on real-time data received from various sensors monitoring both indoor and outdoor temperature and humidity. When the outdoor temperature drops below a certain threshold, the control unit 116 initiates the operation of the furnace alongside the heat pump to ensure that the indoor temperature remains consistent and the humidity comfortable. This integrated approach not only enhances heating performance but also optimizes energy usage by leveraging the strengths of both heating components.

In some embodiments, the hybrid heating system 100-1 comprises a hydronic heat exchanger, geothermal, wood pellet, and/or other heat source to supplement the heat pump. For example, the hydronic heat exchanger operates by circulating heated fluid through a network of pipes, radiators, or underfloor heating systems could distribute heat throughout the building 103. The hydronic heat exchanger could replace the furnace or be added to the heat pump and furnace to allow three heating modalities that can be modulated to control both temperature and humidity.

Referring next to FIG. 1C, a schematic view of the hybrid heating system 100-2 is illustrated according to another embodiment. In the hybrid heating system 100-2, the furnace 128 is in downstream air communication with the indoor coil 108 that is part of a heat pump. A diverter 150 can bypass the furnace 128 in whole or part by moving the baffles 160. The indoor coil 108 preheats incoming air before it reaches the furnace 128 when in boost mode. Such an arrangement allows for an efficient preheating process, which shares the heating load between the heat pump and/or furnace 128 and enhances the overall performance and energy efficiency of the hybrid heating system 100-2. As depicted, diverter 150 is bypassing airflow around the furnace. By moving the baffles 160, the diverter 150 could operate in a boost mode where some or all of the airflow also goes through the furnace 128.

In this alternate configuration, the ODU 118 has the same basic configuration as the embodiment of FIG. 1B. The control unit 116 may operate the ODU 118 differently with appropriate control algorithms and models for operation.

For the IDU 120-2, the return air 135 first encounters the upstream sensor block 123, comprising the upstream temperature sensor 123a and the upstream humidity sensor 123b. These sensors measure the temperature and humidity of the return air and provide real-time data to control unit 116. The air received by the IDU 120-2 first passes through indoor coil 108 where preheating can be performed before optionally receiving additional heating from the furnace 128. A bypass path around furnace 128 is used in some embodiments as depicted.

A mid-stream sensor block 125 between the indoor coil 108 and the furnace 128 measures temperature and humidity. The control unit 116 uses the sensor information determine dew point for the airstream. Depending on the temperature of the furnace 128 condensation is possible for airflow through the furnace depending on the dew point.

The furnace 128 acts as an auxiliary heat source, ensuring that the air is warmed to augment the heat pump when needed, for example, if the outside ambient temperature is too low. The preheated air from the indoor coil 108 of the heat pump is then directed towards the furnace 128 when the diverter 150 is in boost mode, where it is further heated by the heat exchanger 132. The airflow, now heated by both furnace 128 and the heat pump, is circulated throughout the building 103 by the IDU fan 114. The downstream sensor block 130, comprising the downstream temperature sensor 130a and the downstream humidity sensor 130b, monitors the temperature and humidity of the exiting supply air 136. In other embodiments, the upstream temperature sensor 130a and the upstream humidity sensor 130b are located at an exit port of the furnace 128 prior to the IDU fan 114.

Control unit 116 receives data from the upstream, midstream and downstream sensor blocks 123, 125, 130, enabling it to modulate the operation of the furnace 128 and the heat pump to maintain the desired indoor temperature and/or humidity levels. If required, the control unit 116 may deactivate operation of the furnace 128 and ensure that air is heated by the heat pump alone. For example, during moderate weather conditions, the heat pump alone may be sufficient to meet heating demands, while furnace 128 is activated during colder conditions to provide supplementary heating.

Referring to FIG. 2A, a top view of the IDU 120-2 for a hybrid heating system 100 is illustrated with the indoor coil 108 upstream of the furnace 128 like the embodiment of FIG. 1C showing a different physical layout. A furnace zone 206 includes the combustion chamber 134 and a heat exchanger 132. Air flow through the heat exchanger collects heat produced by combustion chamber 134. Furnace 128 is a central heating unit that heats air and distributes it throughout a building 103 via a network of ducts (not shown) as supply air 136 moves by the IDU fan 114.

With reference to FIG. 2B, a side sectional view of the IDU 120-2 is shown operating in a bypass mode. Prior to any diversion, a indoor coil 108 can heat the return air 135. The furnace zone 206 is optionally gated with a baffle 160 that can block airflow to bypass the furnace zone. The baffle 160 of the furnace zone 206 opens and closes to regulate airflow so that it bypasses around the gas furnace 128 or passes through the heat exchanger to further heat the airflow. Baffle 160 rotates to a vertical position to prevent the entry of airflow into the furnace zone. Airflow bypasses around furnace 128 when the damper is in the vertical position.

Moving to FIG. 2C, the IDU 120-2 is shown in a boost mode where both the heat pump and furnace 128 are used to heat the return air. The baffle 160 is rotated to a horizontal position to block the bypass pathway. Airflow through the heat exchanger 132 is opened up in this embodiment so that furnace 128 is now in the airflow to supplement the heat pump.

Referring to FIG. 3A, a schematic view of the IDU 120-1 is shown with a diverter 150 is shown, according to an embodiment of the present disclosure. With the diverter closed, the IDU 120-1 is in shutdown permitting no airflow. The diverter 150 is positioned to optionally bypass furnace 128 in favor of heating with the heat pump alone under certain circumstances within the hybrid heating system 100. The diverter 150 receives air from a return air inlet 135 boosted by the IDU fan 114 that is in air communication with the outside air or recirculated from within building 103. The diverter 150 includes a first outlet 304 directing airflow from the return air inlet 135 to bypass around a furnace zone 206 of the furnace 128, and a second outlet 308 to divert the airflow to the furnace zone 206 of the furnace 128. As depicted, the diverter 150 has blocked both the bypass and the heating path where no conditioning of the airflow is being performed when the IDU 120-1 is inactive. In this embodiment, indoor coil 108 is downstream from furnace 128.

Control unit 116 is configured to manage the operation of the heat pump and the furnace 128 along with airflow within the same by selectively opening and closing the first outlet 304 and the second outlet 308. The first outlet 304 is gated by a first baffle 160-1, and the second outlet 308 gated by a second baffle 160-2. Both the first baffle 160-1 and the second baffle 160-2 are installed at predefined angles with respect to a side of the IDU 120-1. The predefined angles can be either acute or obtuse angles direct air circulation inside the IDU 120-1. This angling of the baffles 160 serves to efficiently redirected the air from the return air inlet 135 based on the heating and comfort requirements. The first and second baffles 160 can be both open partially or completely according to the mix of furnace or heat pump heating under the direction of the control unit 116. When the second baffle 160-2 is closed, air flow is diverted around furnace zone 206 to the indoor coil 108 of the heat pump for electric heating.

The IDU 120-1 includes the IDU fan 114 located at the return air inlet 135 in airflow communication with the diverter 150 in this embodiment. The combustion chamber 134 is in airflow communication with the return air inlet 135 when the second baffle 160-2 is at least partially open. The combustion chamber 134 includes a heating element 318 and a flue fan 320. Furthermore, the heat exchanger 132 is in airflow communication with the combustion chamber 134. The control unit 116 is further configured to operate the flue fan 320 in an inactive mode of the furnace 128, ensuring that the flue fan 320 remains operational to handle residual combustion gases even when the furnace 128 is not actively heating. In addition to adjustment of the dampers 160, control of the combustible fuel fed to the combustion chamber 132 allows modulation of the heating of the furnace 128. Some embodiments could use airflow sensors to measure air movement through the return air inlet 135, furnace zone 206, and/or a first outlet 304.

FIG. 3B depicts the configuration of the IDU 120-1 where the first baffle 160-1 is opened, bypassing the airflow from furnace zone 206 of furnace 128. In this mode, the airflow is directed to the indoor coil 108 of the heat pump to bypass the combustion chamber 134 and the heat exchanger 132, preventing any unneeded heating from the furnace 128 components. This configuration is used during conditions where the heat pump alone is sufficient to meet the heating/cooling requirements or the gas fuel is uneconomical. The bypass damper 160-1 is also used when the heat pump is in cooling mode where heating is not desired. The bypass damper is in airflow communication with the combustion chamber 134.

The bypass damper 160-1 prevents the entry of cold air into the furnace 128 during the cooling operation of the hybrid heating system 100. By sensing the temperature and humidity corresponding to the return air inlet 135 with the upstream sensor block 123 and the temperature of the furnace coils, a dew point can be determined to optimize control of hybrid heating system 100 to avoid condensation in the furnace 128. Depending on the dew point, condensation can form in the furnace. Keeping the furnace coils of the heating element 318 above dew point for air coming in from return air inlet 135, prevents condensation in the furnace coils.

The furnace 128, when eliminating condensation uses the IDU fan 114, the diverter 150, flue fan 320, and/or heating element 318 in various modes. There are three modes listed here to manage furnace condensation under direction from the control unit 116, which may be used in the alternative or overlapping in time in various embodiments. In a first mode, the flue fan 320 of the furnace 128 is activated without any combustion fuel input. This means that the flue fan 320 utilizes existing electromechanical components of the hybrid heating system 100 and operates under a no combustion mode. Indoor, outdoor and coil temperature and humidity are monitored to regulate the flue fan 320 to keep the furnace coils above the dew point. The flue fan 320 evaporates moisture that might condensate with the high velocity airflow into the furnace coils 318 to avoid moisture condensate. The second mode adds radiant electric heat for the inlet to the furnace combustion chamber 134 to increase temperature in addition to airflow induced by the flue fan 320. Gas heat could be used instead of radiant heat in some embodiments. In a third mode, cross-flow dampers could circulate air around the furnace zone 206 using radiant or gas heating to heat the combustion chamber 134 and heat exchanger 132 above the dew point or higher to evaporate moisture.

FIG. 3C illustrates the configuration of the IDU 120-1 where the second baffle 160-2 is opened and the first baffle 160-1 is closed, directing the airflow towards furnace zone 206 of furnace 128. In this mode, the incoming return air 135 from the IDU fan 114 passes the combustion chamber 134, where it is heated by the heating element 318, and then through the heat exchanger 132. The heated air from the furnace 128 is then optionally further heated by the indoor coil 108 prior to being distributed throughout the indoor space of the building 103.

The control unit 116 dynamically adjusts the operation by controlling the flue fan 320, ensuring proper ventilation and preventing the buildup of combustion gases. Additionally, the control unit 116 can modulate the speed of the IDU fan 114 and the heating intensity of the heating element 318 and heat pump to achieve the desired heating level efficiently and maintain optimal indoor comfort. Precise control of the first and second baffles 160 to be partially or fully opened by the control unit 116 allows selection of the heat pump or furnace 128 in greater or lesser degrees to provide precise modulation of the two heat sources.

Referring next to FIG. 3D, another embodiment of the IDU 120-3 is shown that uses the diverter 150 heat with both the furnace 128 and heat pump simultaneously or in the alternative with parallel paths. The indoor coil 108 for the heat pump receives airflow when the first baffle 160-1 of the diverter 150 is opened through a heat pump path that bypasses the furnace heating path. The heating can be modulated independently for the heat pump and the furnace 128 to control each of their contribution to the building temperature. Some embodiments could use two blower fans for each path to control airflow additionally to the regulation provided by the diverter 150.

With reference to FIG. 3E, an embodiment of the IDU 120-2 is shown. In this embodiment, the indoor coil 108 is upstream from the furnace 128 before the diverter 150. The IDU fan 114 takes return air and removes or adds heat using the heat pump. When the first baffle 160-1 is closed as shown, the furnace heating path can be activated to divert airflow to the furnace 128 for additional heating. Where furnace 128 is not needed, the first baffle 160-1 can be opened and the second baffle 160-2 can be closed to bypass airflow around the furnace 128.

Referring next to FIG. 4A, a heat graph shows the furnace 128 and heat pump contributions to heating the building 103 in an embodiment. This hybrid heating system 100 can operate a 36,000 BTU heat pump and/or a 36,000 BTU furnace 128 independently or simultaneously to provide 60,000 BTU per specification of the building 103 in this embodiment. If both heat pump and furnace 128 are operated at maximum output, there is 72,000 BTU and beyond the needs for the building 103. On the left side of the graph, the heat pump is operating alone with precise adjustment of the heating, but once more than 36,000 BTU is requested, a single stage furnace 128 is activated. The heat pump output is controllable, but the furnace 128 is either active or not to provide the heat requested by the thermostat 138 of the building 103. The furnace 128 can be smaller than what could heat the building alone with the heat pump being available all the time.

With reference to FIG. 4B, a heat graph shows a two-stage heat pump being used with neither the furnace 128 nor the heat pump able to provide the 60,000 BTU heating alone. Working in concert, the furnace 128 and heat pump can meet the heating need of the building 103.

Referring next to FIG. 4C, a heat graph is shown using undersized heat pump and furnace 128 where neither can provide the heating for the building 103 alone. High efficiency heat pumps and furnaces 128 provide control of their output precisely. On the left of the heat graph, the heat pump operates alone to meet the heating requirements. On the right of the heat graph, both the gas furnace 128 and heat pump are used in a high efficiency mode to provide the heating to the building according to desired humidity, relative fuel costs, etc. Here, the gas furnace is run at maximum once the heat pump is maxed out with the heat pump slowly ramped up to meet further demand.

With reference to FIG. 4D, a heat graph is shown with a high efficiency heat pump with the furnace 128 filling in the rest. The furnace 128 has a modulating gas regulator to augment heating with the furnace 128 with the additional heating specified by the thermostat 138.

Referring next to FIG. 4E, a heat graph is shown with a modulated furnace and high efficiency heat pump. The furnace 128 is active the entire time depicted to dry out the humidity inside the building. Measuring outside humidity and the humidity after heating, the diverter, fans, relative mix from heating sources can be modulated to achieve the desired humidity.

With reference to FIG. 4F, a heat graph is shown where the division between heat pump and furnace heating varies based upon many factors. Humidity, IoT sensing, coefficient of performance (COP), air quality, etc. can be measured to affect what portion of the heating is from the furnace 128 and what portion is from the heat pump at any given moment. IoT sensors in the thermostats and other IoT devices can measure temperature, humidity, VOCs, etc. with the hybrid heating system 100 to vary the mix between heat pump and furnace heating. Modes such as: electric heat only, gas heat only, humidity range, predictive scheduling, etc., can be selected to vary the mix of heating sources. Machine learning models could be used to more accurately meet the specified goals. Things such as grid pricing of electricity or gas, time of day utility tariffs, localized weather forecasts, etc. can be used to adjust the mix between heating sources in various embodiments

Referring to FIG. 5, a method 500 for controlling heat and comfort of a building by a hybrid heating system 100 is shown according to an embodiment of the present disclosure. Some steps of method 500 are performed by the hybrid heating systems 100 in various embodiments by utilizing the control unit 116.

At block 502, the outdoor temperature and humidity sensors 122a, 122b are read by the control unit 116. The temperature sensors and humidity sensors 122a, 122b provide real-time readings of the environmental conditions outside the building 103. For instance, an outdoor temperature sensor 122a might indicate that the outdoor temperature is 50° F. (10° C.), while a outdoor humidity sensor 122b reports 60% relative humidity. The readings are inputs for the control algorithm, enabling the hybrid heating system 100 to determine the most efficient heating strategy based on current weather conditions and desired comfort.

At block 504, the operation of the heat pump is controlled based on the received outdoor temperature and humidity data. The control unit 116 analyzes the inputs to determine the operation mode for the heat pump. For example, if the outdoor temperature is relatively mild and within a range suitable for efficient heat pump operation, the control unit 116 may activate the heat pump in heating mode. The heat pump's compressor and intake fan speed may be adjusted dynamically to maintain efficient heating while minimizing energy consumption. This adaptive control strategy operates the heat pump effectively in varying weather conditions to control comfort indoors while adjusting energy efficiency.

At block 506, the downstream temperature is read by a downstream temperature sensor 130A located within the hybrid heating system 100 or at an exit of the IDU 120 of the hybrid heating system 100. The downstream temperature sensor 130A, typically positioned in the vicinity where heated air exits the hybrid heating system 100 or could be in the building's conditioned space, monitors the temperature of the air supplied to the indoor space. For instance, if the desired indoor temperature is set to 72° F. (22° C.), the downstream temperature sensor 130A measures that the air leaving the hybrid heating system 100 is currently 68° F. (20° C.). This feedback enables the control unit 116 to assess whether the heating output needs adjustment to achieve the desired indoor temperature effectively.

At block 508, the control unit 116 compares the downstream temperature measured at block 506 with the desired indoor temperature setpoint entered with a thermostat interface. If the downstream temperature deviates from the desired temperature range, the control unit 116 proceeds to adjust the heating operation accordingly. For example, if the measured downstream temperature is below the desired setpoint, indicating insufficient heating, the control unit 116 initiates corrective actions to increase heating output. Conversely, if the downstream temperature exceeds the desired setpoint, the control unit 116 may reduce heating output to avoid overheating the indoor space, to adjust comfort and energy efficiency.

At block 510, if the downstream temperature does not match the desired setpoint, the control unit 116 verifies whether adjustments to the heat pump operation are necessary. For instance, if the heat pump is operating efficiently and maintaining the desired indoor temperature within acceptable limits, the control unit 116 continues monitoring the hybrid heating system 100 for any changes in environmental conditions. If adjustments are not deemed necessary due to external factors like fluctuating outdoor temperatures or occupancy patterns, the control unit 116 transitions to block 520 to further evaluate humidity levels downstream.

At block 512, the control unit 116 assesses whether the heat pump is operating at or near its maximum heating capacity. This determination involves monitoring the performance metrics of the heat pump, such as compressor speed and heating output. For example, if the outdoor temperature drops significantly, requiring higher heating capacity, the control unit 116 checks whether the heat pump is already operating at or near its maximum heating capacity or if the outside temperature is outside of the range of the heat pump to work efficiently. If the heat pump is outside of its capabilities, the control unit 116 may consider activating supplementary heating sources, like the furnace 128, to meet increased heating demands. Where the heat pump is within normal operating parameters, processing loops back from block 512 to block 504 to continue control of the hybrid heating system 100 using the heat pump alone.

At block 514, if the control unit 116 determines that the heat pump is operating at its maximum capacity or operating with outside temperatures too cold, or if additional heating power is required to achieve the desired indoor temperature, it activates the furnace 128. The furnace 128, equipped with a IDU fan 114 and heating element 318, can provide supplemental heat to augment the heating output from the heat pump. For instance, during extremely cold weather conditions where the heat pump alone may not suffice to maintain indoor heat, activating the furnace 128 ensures consistent and adequate heating throughout the building.

At block 516, the control unit 116 re-evaluates the downstream temperature after activating the furnace 128 to ensure it aligns with the desired indoor temperature. If the downstream temperature remains outside the desired setpoint, indicating inadequate heating despite furnace 128 activation, the control unit 116 proceeds to adjust the furnace 128 operation accordingly. This iterative process allows the hybrid heating system 100 to fine-tune its performance dynamically, responding promptly to changes in indoor temperature requirements and external environmental conditions for optimal comfort and efficiency.

At block 518, if the downstream temperature deviates from the desired setpoint after furnace 128 activation, the control unit 116 adjusts the furnace 128 operation to achieve the desired indoor temperature and humidity. This adjustment may involve regulating the IDU fan 114 speed and adjusting the heating intensity of the heating element 318 within the furnace 128. For instance, if the indoor temperature is below the desired setpoint, the control unit 116 increases furnace 128 output to raise the temperature to the desired level, ensuring consistent comfort throughout the building. To change the humidity, the mix in production between the furnace 128 and the heat pump can be adjusted using the damper 160.

At block 520, if the control unit 116 determines that the downstream temperature matches the desired setpoint, it proceeds to read the downstream humidity using a humidity sensor integrated into the hybrid heating system 100. This sensor measures the relative humidity level of the air exiting the hybrid heating system 100, providing critical data on indoor air quality and comfort conditions. For example, if the desired indoor humidity level is 40% and the sensor detects 50% humidity, the control unit 116 evaluates whether humidity adjustment is necessary to maintain optimal indoor comfort.

At block 522, the control unit 116 compares the downstream humidity level measured at block 520 with the desired indoor humidity setpoint. If the measured humidity deviates from the desired range, indicating suboptimal indoor air comfort, the control unit 116 proceeds to implement humidity control strategies. For instance, if the downstream humidity exceeds the desired setpoint, the control unit 116 may activate dehumidification mechanisms within the hybrid heating system 100 to reduce humidity levels effectively, ensuring a comfortable and healthy indoor environment. For example, by looping back to block 518 the furnace can decrease humidity. Looping back to block 510 to use the heat pump to dehumidify the air provided to the building.

At block 524, if the control unit 116 determines that humidity levels and temperature downstream are within the desired range, it maintains the current heating mode without additional adjustments. This ensures that the hybrid heating system 100 continues to operate efficiently and effectively, providing consistent indoor comfort while optimizing energy consumption. For example, if both temperature and humidity conditions are optimal, the control unit 116 may maintain the current heating mode to prevent unnecessary cycling of heating components, thereby prolonging equipment lifespan and reducing operational costs.

Referring to FIG. 6, a comfort control method 600 for controlling heat and humidity of a building 103 with a hybrid heating system 100 is illustrated according to an embodiment of the present disclosure. At block 602, the outdoor temperature and humidity are received by a control unit 116 of the hybrid heating system 100. This involves gathering real-time data from sensors positioned in the ODU 118 outside the building to monitor environmental conditions. For instance, temperature sensors may report that the outdoor temperature is 41° F. (5° C.), while humidity sensors indicate a relative humidity of 70%. These inputs are used for the control unit 116 to assess the current weather conditions and adjust the heating strategy accordingly.

At block 604, the control unit 116 calculates the setpoint temperature based on user-defined preferences and/or automated algorithms. For example, if the desired indoor temperature is set to 72° F. (22° C.), the control unit 116 establishes this as the target to achieve within the building. This setpoint temperature serves as a reference point throughout the heating control process, guiding operation of the hybrid heating system 100 to maintain optimal comfort for occupants.

At block 606, the control unit 116 computes the temperature differential by comparing the setpoint temperature determined at block 604 with the current downstream temperature measured within the building. For instance, if the setpoint temperature is 72° F. (22° C.) and the downstream temperature reads 65° F. (18° C.), the control unit 116 calculates a differential of 7° F. (4° C.). This differential provides insight into the heating requirements necessary to achieve the desired indoor temperature effectively.

At block 608, the control unit 116 evaluates whether the temperature differential calculated at block 606 exceeds a predefined threshold. This threshold serves as a criterion to determine whether additional heating capacity beyond the heat pump's capability is required. For example, if the predefined threshold is set to 4° F. (2° C.) and the temperature differential is 7° F. (4° C.), the control unit 116 determines that supplemental heating, such as furnace 128 activation in block 612, to achieve the desired indoor temperature more quickly. Where the differential is less than the predefined threshold, the method progresses to block 610 to continue reliance on the heat pump for heating in the hybrid heating system 100.

At block 610, if the control unit 116 determines that the temperature differential does not exceed the predefined threshold, indicating that the heat pump alone can sufficiently meet the heating requirements, it operates the heat pump. This involves controlling the heat pump's compressor and intake fan to regulate heating output and maintain indoor comfort. For instance, during moderate outdoor temperatures where the heat pump operates efficiently, the control unit 116 adjusts its settings to ensure consistent and energy-efficient heating without activating the furnace 128.

At block 612, if the control unit 116 determines that the temperature differential exceeds the predefined threshold, indicating a need for additional heating power, it operates the furnace 128. This entails activating the furnace's IDU fan 114 and heating element 318 to supplement the heat pump's heating output. For example, during extreme cold spells where the heat pump alone may struggle to achieve the desired indoor temperature, activating the furnace ensures adequate heating capacity to maintain comfort indoors effectively. The furnace 128 may be upstream or downstream of the heat pump in different embodiments. Where the furnace 128 is before the heat pump, the furnace 128 may heat the air to be within the temperature ranges that the heat pump operates. Where the furnace is after the heat pump, it can supply supplemental heat when the heat pump cannot generate the desired indoor temperature. In some cases, the furnace may be used to more quickly provide heat or modulate the humidity according to algorithms in the control unit 116.

At block 614, the control unit 116 reads and evaluates the downstream temperature and humidity using sensors positioned within the building's hybrid heating system 100 regardless of which heating sub-systems are being used as determined in blocks 610 or 612. This data provides feedback on the actual conditions experienced by occupants. For instance, if the downstream temperature is measured at 70° F. (21° C.) and the humidity level is 45%, the control unit 116 uses this information to assess indoor comfort levels and determine if adjustments are necessary to maintain desired conditions.

At block 616, the control unit 116 compares the downstream temperature measured at block 614 with the desired indoor temperature setpoint established at block 604. If the downstream temperature deviates from the desired setpoint, indicating a need for heating adjustment, the control unit 116 proceeds to both blocks 618 and 622 to evaluate humidity conditions and monitor further adjustments. If the downstream temperature aligns with the desired setpoint, the control unit 116 directs the process to block 620 to consider additional heating adjustments if necessary. There may be an acceptable deviance allowed before correction of the temperature, for example, differences of less than 3% between the desired temperature and the downstream temperature.

At block 618, the control unit 116 compares the downstream humidity level measured at block 614 with the desired indoor humidity setpoint. If the humidity deviates from the desired range outside of the acceptable deviance, indicating suboptimal indoor air quality, the control unit 116 proceeds to implement humidity control strategies. For example, if the downstream humidity exceeds the desired setpoint, the control unit 116 may activate dehumidification mechanisms within the hybrid heating system 100 to reduce humidity levels effectively, ensuring a comfortable and healthy indoor environment.

At block 620, the control unit 116 adjusts the heating operation of the heat pump and/or furnace based on the feedback from blocks 616 and 618. This adjustment may involve fine-tuning the heat pump's compressor speed, activating/deactivating the furnace's heating element 318, and/or manipulating the dampers 160 to achieve the desired indoor temperature and humidity levels. For instance, if the downstream temperature is slightly below the setpoint, the control unit 116 may increase the heat pump's heating output or activate the furnace at a lower intensity to maintain consistent comfort levels without overshooting the setpoint. A modulating gas regulator for the furnace 128 can change the heating in the combustion chamber. A dehumidification or condensation cycle can be performed by modulating heat pump and furnace 128 heating relative to each other to aid in achieving the desired humidity.

At block 622, the control unit 116 continues to monitor the downstream temperature and humidity conditions following adjustments made at block 620. This ongoing monitoring ensures that the hybrid heating system 100 maintains optimal indoor comfort levels in response to changing environmental conditions and occupancy patterns. For example, if the downstream temperature increases after heating adjustments, the control unit 116 may regulate the furnace 128 operation to prevent overheating and maintain energy efficiency throughout building 103.

At block 624, the control unit 116 evaluates the activation conditions for furnace 128, dampers 160 and heat pump based on comprehensive environmental data, including temperature and humidity levels. This assessment checks that heating operations are optimized for both comfort and energy efficiency before looping back to blocks 610 and 612 for further analysis and adjustment. For instance, if the control unit 116 detects that the indoor humidity levels are higher than the desired setpoint, indicating a need for dehumidification, it may deactivate the heat pump temporarily. This action prevents additional moisture from entering the indoor space through the ventilation process, helping to maintain optimal humidity levels and comfort.

Alternatively, if the indoor humidity levels are within the desired range but the temperature differential indicates a need for increased heating capacity, the control unit 116 may activate both the heat pump and furnace simultaneously. This dual operation allows the heat pump to provide primary heating while the furnace 128 supplements with additional warmth, ensuring that the indoor environment remains comfortable and balanced.

In another scenario, during periods of low outdoor humidity coupled with cold temperatures, the control unit 116 may prioritize heat pump activation over the furnace 128. This decision maximizes energy efficiency by leveraging the heat pump's ability to extract heat from the outdoor air, maintaining comfortable indoor conditions without relying heavily on furnace-based heating. By continuously monitoring and adjusting the activation conditions of the furnace and heat pump based on real-time environmental factors, the control unit 116 optimizes heating performance while minimizing energy consumption and ensuring consistent indoor comfort levels.

Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.

Implementation of the techniques, blocks, steps and means described above may be done in various ways. For example, these techniques, blocks, steps and means may be implemented in hardware, software, or a combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described above, and/or a combination thereof.

Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a swim diagram, a data flow diagram, a structure diagram, or a block diagram. Although a depiction may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function.

Furthermore, embodiments may be implemented by hardware, software, scripting languages, firmware, middleware, microcode, hardware description languages, and/or any combination thereof. When implemented in software, firmware, middleware, scripting language, and/or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine-readable medium such as a storage medium. A code segment or machine-executable instruction may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a script, a class, or any combination of instructions, data structures, and/or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, and/or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

For a firmware and/or software implementation, the methodologies may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software codes may be stored in a memory. Memory may be implemented within the processor or external to the processor. As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other storage medium and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored.

Moreover, as disclosed herein, the term “storage medium” may represent one or more memories for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage mediums, optical storage mediums, flash memory devices and/or other machine-readable mediums for storing information. The term “machine-readable medium” includes but is not limited to portable or fixed storage devices, optical storage devices, and/or various other storage mediums capable of storing that contain or carry instruction(s) and/or data.

While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the disclosure.