SYSTEM AND METHOD FOR CONTROLLING AN HVAC UNIT

Description

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims the benefit of U.S. Provisional Patent Application No. 63/669,451, filed on Jul. 10, 2024, which is incorporated by reference herein in its entirety.

BACKGROUND

Embodiments described herein relate to the field of heating, ventilation, and air conditioning (HVAC) units, and more particularly, to a system and a method for controlling an HVAC unit.

SUMMARY

Described herein is a system for controlling a heating, ventilation, and air conditioning (HVAC) unit. The system comprises the HVAC unit comprising an indoor coil, and one or more fans configured with the indoor coil, and a controller. The controller is configured to monitor temperature of air upstream and downstream of the indoor coil, and control, based on the monitored temperature, speed of the one or more fans to maintain a temperature difference across the indoor coil.

In one or more embodiments, during a cooling mode of operation of the HVAC unit, the temperature difference is selected based on an operating environment of an outdoor unit of the HVAC unit.

In one or more embodiments, the operating environment is selected from one of a humid condition, a semi-arid condition, and a desert condition, wherein the humid condition pertains to a first range of humidity, a semi-arid condition pertains to a second range of humidity, and a desert condition pertains to a third range of humidity, wherein the first range is greater than the second range and the second range is greater than the third range.

In one or more embodiments, during a cooling mode of operation of the HVAC unit, the temperature difference is selected based on a humidity level.

In one or more embodiments, the controller is further configured to monitor temperature and/or pressure of refrigerant vapor leaving the indoor coil during the cooling mode and correspondingly determine the operating environment of the HVAC unit.

In one or more embodiments, the controller is further configured to monitor superheat control characteristics of an expansion valve of the HVAC unit during the cooling mode and correspondingly determine the operating environment of the HVAC unit.

In one or more embodiments, the system further comprises a humidity sensor in communication with the controller, to monitor specific humidity or relative humidity around an outdoor coil of the HVAC unit, wherein the controller is further configured to determine the operating environment of the HVAC unit based on the monitored humidity.

In one or more embodiments, during a heating mode of operation of the HVAC unit, the controller is configured to control the speed of the one or more fans to maintain a temperature downstream of the indoor coil.

In one or more embodiments, the one or more fans are configured downstream and/or upstream of the indoor coil.

In one or more embodiments, the system further comprises a first temperature sensor and a second temperature sensor positioned upstream and downstream, respectively, of the indoor coil of the HVAC unit, to monitor temperature of the air upstream and downstream, respectively, of the indoor coil.

In one or more embodiments, the system further comprises a human-machine interface (HMI) device in communication with the controller, the HMI device configured to display and/or allow selection of the operating environment during the cooling mode, display and/or allow selection of the temperature difference to be maintained across the indoor coil during the cooling mode and/or the heating mode, and display and/or allow selection of the temperature to be maintained downstream of the indoor coil during the heating mode.

Also described herein is a method for controlling an HVAC unit, the HVAC unit comprising an indoor coil, and one or more fans configured with the indoor coil. The method comprises monitoring, by a controller, temperature of air upstream and downstream of the indoor coil, and controlling, by the controller, based on the monitored temperature, speed of the one or more fans to maintain a temperature difference across the indoor coil.

In one or more embodiments, during a cooling mode of operation of the HVAC unit, the method comprises the steps of selecting and maintaining, by the controller, the temperature difference based on an operating environment of an outdoor unit associated with the HVAC unit.

In one or more embodiments, the operating environment is selected from one of a humid condition, a semi-arid condition, and a desert condition, wherein the humid condition pertains to a first range of humidity, a semi-arid condition pertains to a second range of humidity, and a desert condition pertains to a third range of humidity, and wherein the first range is greater than the second range and the second range is greater than the third range.

In one or more embodiments, during a cooling mode of operation of the HVAC unit, the temperature difference is selected based on a humidity level.

In one or more embodiments, the method comprises the steps of monitoring temperature and/or pressure of refrigerant vapor leaving the indoor coil during the cooling mode and correspondingly determining the operating environment of the HVAC unit.

In one or more embodiments, the method comprises the steps of monitoring superheat control characteristics of an expansion valve of the HVAC unit during the cooling mode and correspondingly determining the operating environment of the HVAC unit.

In one or more embodiments, the method comprises the steps of monitoring, using a humidity sensor of the HVAC unit, specific humidity or relative humidity around an outdoor coil of the HVAC unit, and determining, by the controller, the operating environment of the HVAC unit based on the monitored humidity.

In one or more embodiments, during a heating mode of operation of the HVAC unit, the method comprises the step of controlling, by the controller, the speed of the one or more fans to maintain a temperature downstream of the indoor coil.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, features, and techniques of the subject disclosure will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the subject disclosure of this disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the subject disclosure and, together with the description, serve to explain the principles of the subject disclosure.

In the drawings, 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 with a second 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.

FIGS. 1A and 1B illustrate exemplary schematic representations of a system for controlling a heating, ventilation, and air conditioning (HVAC) unit, which allows an indoor unit in the HVAC unit to harmonize its operation with the capacity being produced by an outdoor unit in accordance with one or more embodiments of the subject disclosure.

FIG. 2 illustrates an exemplary block diagram of the system of FIGS. 1A and 1B, in accordance with one or more embodiments of the subject disclosure.

FIG. 3 illustrates exemplary steps involved in a method for controlling an HVAC unit, which allows the indoor unit in the HVAC unit to harmonize its operation with the capacity being produced by the outdoor unit in accordance with one or more embodiments of the subject disclosure.

DETAILED DESCRIPTION

The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject disclosure as defined by the appended claims.

Various terms are used herein. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the subject disclosure, the components of this disclosure described herein may be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower,” “first,” “second” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components.

Split heating, ventilation, and air conditioning (HVAC) systems are employed for maintaining indoor air quality and comfort in residential, commercial, and industrial buildings. In HVAC systems, improved efficiency may be achieved through the use of variable capacity systems that have the ability to adjust their output to match the current demand. Such systems may modulate their capacity to provide the necessary heating or cooling, thereby avoiding the energy waste associated with systems that operate at a constant capacity regardless of demand fluctuations.

An important aspect of achieving high efficiency in variable capacity systems is the coordination between the outdoor unit's capacity and indoor airflow. When the capacity of the outdoor unit increases or decreases, the indoor airflow may be adjusted proportionately. This may ensure that the system may operate at its optimum efficiency, maintaining comfort while optimizing energy consumption.

In systems equipped with communicating controls, this coordination may be easily managed. Communicating controls may allow the indoor and outdoor units to exchange information in real-time, enabling precise adjustments in airflow to match the varying capacity of the outdoor unit. However, systems with communicating controls may come with higher costs due to the complexity and additional components required for communication.

To address the above limitations associated with communicating controls, there is a need for variable speed systems that may utilize non-communicating controls to establish coordination between the outdoor and indoor units. This may reduce overall system costs and complexity by eliminating the need for communication protocols between the indoor and outdoor units.

Referring to FIGS. 1A to 2, a system 100 for controlling an HVAC unit 100A is disclosed. The HVAC unit 100A may include an indoor unit connected to an outdoor unit 124 (also referred to as outdoor equipment) via a refrigeration circuit. The indoor unit 102 may be in fluidic communication with an area of interest (AOI 104). The AOI 104 may be a space or room associated with a building. The AOI 104 may also be a storage space associated with a container or a cargo truck but is not limited to the like. The system 100 may further include one or more fans 106 configured with indoor coil (also designated as 102, herein) associated with the indoor unit, where the fans 106 may enable ambient air, return air from the AOI 104, or a combination thereof to flow into the AOI 104 while flowing through the indoor coil 102. The indoor unit 102 and the outdoor unit 124 may be heat exchangers that may function as a condenser as well as an evaporator, based on the mode of operation of the HVAC unit 100A. In one or more embodiments, the HVAC unit 100A or refrigeration circuit may include but is not limited to a compressor 126, an expansion valve 128, a reversing valve (not shown), an accumulator (not shown), a discharge muffler (not shown), and an oil separator (not shown).

In one or more embodiments, the indoor coil 102 and the fan(s) 106 may be configured in a duct system 112 that may fluidically connect the indoor unit to the AOI 104. The duct system 112 may include a supply air duct extending between the ambient and the AOI 104 to allow the flow of ambient air from the ambient into the AOI 104 while flowing the received air through the indoor coil 102. The duct system 112 may further include a return air duct that may be configured to receive return air from the AOI 104 and further supply the received return air into the AOI 104 while flowing the received return air through the indoor coil 102. Accordingly, the duct system 112 may enable the flow of air (ambient air and/or return air) (provided to the HVAC unit 100A) through the indoor coil 102 and then into the AOI 104.

In one or more embodiments, the fan(s) 106 may be a variable speed fan configured with the duct system 112 to enable circulation of the air between the ambient and the AOI 104 and further enable the flow of the air through the indoor coil 102 before being supplied to the AOI 104. However, in one or more embodiments, in a multi-fan configuration, at least one of the fans 106 may be a variable speed fan 106 and the remaining fans 106 may be a single speed fan 106, to enable circulation of the air between the ambient and the AOI 104. In one or more embodiments, the fan(s) 106 may be positioned before (upstream of) the indoor coil 102 as shown in FIG. 1A and/or after (downstream of) the indoor coil 102 as shown in FIG. 1B.

In some embodiments, the system 100 may include an air handling unit (AHU) associated with the AOI 104, which may include the fan(s) 106 and the indoor unit 102 configured in the duct system 112. The fan 106 of the AHU may enable circulation of the air between the ambient and the AOI 104 and also enable the flow of the air through the indoor coil 102. In one or more embodiments, the system 100 or AHU may also include a supplemental electric heater (not shown) of a fixed or variable capacity which may be configured upstream or downstream of the indoor coil 102 within the duct system 112. The electric heater may be configured to adjust the temperature and humidity of the air flowing through the duct system 112 before being supplied to the AOI 104.

The system 100 may further include a first temperature sensor 114 that may be positioned downstream of the indoor coil 102 to monitor the temperature of the air leaving the indoor coil 102. Further, the system 100 may include a second temperature sensor 116 that may be positioned upstream of the indoor coil 102 within the duct system 112 to monitor the temperature of the return air upstream of the indoor coil 102. Accordingly, the first temperature sensor 114 and the second temperature sensor 116 may enable monitoring of the air temperature difference across the indoor coil 102.

In one or more embodiments, the system 100 may further include a thermostat 118 positioned within the AOI 104 or installed on the HVAC unit 100A. The thermostat 118 may be configured to enable occupants of the AOI 104 to set one or more of, a temperature of the air to be supplied into the AOI 104 and a temperature to be maintained within the AOI 104 based on the occupant's comfort.

The system 100 may further include a controller 110 in communication with the indoor unit, a drive 108 (motor) associated with fan(s) 106, the AHU, the first temperature sensor 114, the second temperature sensor 116, and the thermostat 118.

The operation of the controller 110 may reduce operational latency between the controller 110, and the components of the HVAC unit 100A, thereby improving precision of control and performance of the HVAC unit 100A. Furthermore, the communication of the electronic control signals between the controller 110 and the flow control devices may be achieved through an encryption authorization protocol, such as Transport Layer Security (TLS), Internet Protocol Security (IPsec), Symmetric-Key Encryption, custom cryptographic protocols, Secure Boot/Trusted Platform Modules (TPMs), Hardware Security Modules (HSMs), Building Automation and Control Network (BACnet) or BACnet Secure Connect (BACnet/SC), Modbus TLS, and the like, but not limited thereto. This secure transmission allows for security of the controller 110 by preventing unauthorized access by nature of the secure transmission between the controller 110, and other components of the HVAC unit 100A.

Referring to FIG. 2, the controller 110 may comprise one or more processors 110-1 coupled to a memory 110-2 storing instructions executable by the one or more processors 110-1, which may enable the controller 110 to perform one or more designated operations.

Referring back to FIGS. 1A to 2, in one or more embodiments, the controller 110 may be configured to monitor the temperature of air upstream and downstream of the indoor coil 102 using the first temperature sensor 114 and the second temperature sensor 116, respectively. Further, based on the monitored temperatures, the controller 110 may determine a temperature difference across the indoor coil 102. Accordingly, the controller 110 may actuate the drive 108 to control the speed of the fan(s) 106 configured with the indoor coil 102 to maintain a temperature difference across the indoor coil 102 or maintain a temperature difference between the first temperature sensor 114 and the second temperature sensor 116.

It is to be appreciated that the fan 106 and fan drive 108 in the air stream may also add some heat across the indoor coil 102. To eliminate the effect of fan heat on the temperature difference measurement across the indoor coil 102, the first temperature sensor 114 and the second temperature sensor 116 may be positioned between the fan and the indoor coil 102 to eliminate the effect of fan heat on the temperature difference measurement across the indoor coil 102. Alternatively, the added heat of the fan 106 and fan drive 108 may also be determined from characterization of fan speed and motor current, which may then be considered to compensate the added heat and correspondingly measure the temperature difference across the indoor coil 102.

In one or more embodiments, during a cooling mode of operation of the HVAC unit 100A, the temperature difference to be maintained (which may be predetermined or dynamically determined based on operational loads, for example) across the indoor coil 102 may be selected based on the operating environment around the outdoor unit 124 of the HVAC unit 100A. Accordingly, based on the operating environment of the outdoor coil, the controller 110 may control the speed of the fan(s) 106 configured with the indoor coil 102 to maintain the temperature difference across the indoor coil 102 during the cooling mode.

In one or more embodiments, the operating environment may be selected from one of a humid condition, a semi-arid condition, and a desert condition. The humid condition may pertain to a first range of humidity, a semi-arid condition may pertain to a second range of humidity, and a desert condition may pertain to a third range of humidity. In one or more embodiments, the first range may be greater than the second range and the second range may be greater than the third range. In an example, the humid condition may pertain to a humidity level of 50% or higher, the semi-arid condition may pertain to a humidity level of 25 and 50%, and the desert condition may pertain to a humidity level below 25%. Accordingly, in one or more embodiments, based on the operating environment, the predetermined temperature difference to be maintained across the indoor coil 102 for the humid condition, the semi-arid condition, and the desert condition may be 18° F., 21° F., and 24° F., respectively, with a tolerance level of +10%.

In one or more embodiments, the controller 110 may be configured to monitor the temperature and/or pressure of refrigerant vapor leaving the indoor coil 102 during the cooling mode and correspondingly determine the operating environment of the HVAC unit 100A or outdoor coil. The temperature and/or pressure of the refrigerant vapor leaving the indoor coil 102 may be indicative of the operating environment of the outdoor unit 124 of the HVAC unit 100A, due to the thermodynamical relationship between the temperature and the pressure of the refrigerant vapor. Since each operating environment may have different temperatures and pressures (and corresponding have different operational loads), the controller may determine and adjust operation of the HVAC unit 100A based on the temperature and/or pressure. For a given airflow rate and compressor speed, the temperature and pressure of the refrigerant may be higher for higher levels of humidity in the air entering indoor coil 102. For example, a refrigerant temperature of about 54 F and saturation temperature of about 49 F may indicate a humid environment, a refrigerant temperature of about 51 F and saturation temperature of about 46 F may indicate a semi-arid environment and a refrigerant temperature of about 48 F and saturation temperature of about 43 F may indicate a desert environment. In such embodiments (not shown), the system 100 may include an additional temperature sensor and a pressure sensor configured in the refrigeration circuit of the HVAC unit 100A to monitor the temperature and pressure of the refrigerant vapor leaving the indoor coil 102.

Further, in one or more embodiments, the controller 110 may be configured to monitor the superheat control characteristics of the expansion valve 128 of the HVAC unit 100A during the cooling mode. The superheat control characteristics may be indicative of the operating environment of the HVAC unit 100A. In superheat control means, such as those employing thermostatic expansion valves (TXVs), the superheat may be regulated to or within a known value. For example, superheat control means may produce a known amount of superheat, such as 5° F. If the superheat control characteristics are known and consistent, the operating environment may be inferred using only the vapor temperature or vapor pressure (from which saturation temperature is derived). For instance, a vapor temperature of 54° F. (implying a saturation temperature of 49° F.) may indicate a humid environment, while temperatures of 51° F. and 48° F. may correspond to semi-arid and desert conditions, respectively. Additionally, known variation profiles of superheat across temperature ranges for specific TXVs may be considered to improve accuracy when interpreting vapor temperature or saturation temperature. The superheat control characteristics may correspondingly enable the controller 110 to determine the operating environment of the HVAC unit 100A or outdoor coil and accordingly control the speed of the fan(s) 106 configured with the indoor coil 102 to maintain the predetermined temperature difference across the indoor coil 102.

Furthermore, in one or more embodiments, the system 100 may include a humidity sensor 120 in communication with the controller 110 as shown in FIG. 2, to monitor specific humidity or relative humidity around an outdoor coil of the HVAC unit 100A and transmit the monitored humidity data to the controller 110. Accordingly, the controller 110 may determine the operating environment of the HVAC unit 100A based on the monitored humidity. This may enable an automated operating environment selection by the system 100, allowing the controller 110 to automatically determine the predetermined temperature difference to be maintained across the indoor coil 102 and accordingly control the speed of the fan(s) 106 to maintain the predetermined temperature difference across the indoor coil 102.

Further, in one or more embodiments, during a heating mode of operation of the HVAC unit 100A, the controller 110 may be configured to control the speed of the fan(s) 106 to maintain a constant temperature difference across the indoor coil 102, without any adjustment based on the operating environment of the outdoor coil. In addition, in other embodiments, during the heating mode of operation of the HVAC unit 100A, the controller 110 may also be configured to control the speed of the fan(s) 106 to maintain a temperature (leaving air temperature) downstream of the indoor coil 102, instead of maintaining a constant temperature difference across the indoor coil 102. In one or more embodiments, the temperature to be maintained downstream of the indoor coil 102 may be predetermined/predefined. In other embodiments, the temperature may be determined based on other parameters, such as operational load and/or operational environment. In such embodiments, the controller 110 may be configured to receive, from the thermostat 118, data pertaining to the temperature for the air to be supplied to the AOI 104 and accordingly vary fan speed so that the temperature reported by sensor 114 matches the value received from the thermostat.

In one or more embodiments, the system 100 may include a human-machine interface (HMI) device 122 in communication with the controller 110. The HMI device 122 may be configured to display and/or allow selection of the operating environment during the cooling mode. Further, the HMI device 122 may be configured to display and/or allow the selection of the predetermined temperature difference to be maintained across the indoor coil 102 during the cooling mode and/or the heating mode. Furthermore, the HMI device 122 may be configured to display and/or allow the selection of the temperature to be maintained downstream of the indoor coil 102 (or leaving air temperature) during the heating mode. In one or more embodiments, the HMI device 122 may be the thermostat 118 of the HVAC unit 100A. Further, the HMI device 122 may be mobile devices associated with occupants of the AOI 104 or registered users or an admin of the HVAC unit 100A.

The controller 110, the indoor unit, the fan drive 108, the thermostat 118, the first temperature sensor 114, the second temperature sensor 116, the humidity sensor 120, and other components of the HVAC unit 100A may include a transceiver or a communication module to communicatively connect the controller 110 to one or more of the fan drive 108, the thermostat 118, the first temperature sensor 114, the second temperature sensor 116, the humidity sensor 120, and other components of the HVAC unit 100A through a network via wired and/or wireless media. In one or more embodiments, the system 100 or controller 110, and mobile devices associated with the occupants of the AOI 104 or registered users or the admin may be operatively coupled to a website and so be operable from any Internet-enabled user device. The mobile devices may allow the occupants, the users, and the admin to monitor and control the operation of the system 100. Examples of mobile devices may include but are not limited to, a portable computer, a personal digital assistant, a handheld device, and a workstation.

In one or more embodiments, the network may be a wireless network, a wired network or a combination thereof. Network can be implemented as one of the different types of networks, such as intranet, local area network (LAN), wide area network (WAN), the internet, and the like. Further, the network may either be a dedicated network or a shared network. The shared network represents an association of the different types of networks that use a variety of protocols, for example, Hypertext Transfer Protocol (HTTP), Transmission Control Protocol/Internet Protocol (TCP/IP), Wireless Application Protocol (WAP), and the like, to communicate with one another. Further, network can include a variety of network devices, including transceivers, routers, bridges, servers, computing devices, storage devices, and the like. In another implementation, the network may be a cellular network or mobile communication network based on various technologies, including but not limited to, Global System for Mobile (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Long Term Evolution (LTE), WiMAX, 5G or 6G network protocols, and the like.

Referring to FIG. 3, method 300 for controlling the operation of an HVAC unit having an indoor coil, and one or more fans configured with the indoor coil is disclosed, which allows the indoor unit in the HVAC unit to harmonize its operation with the capacity being produced by the outdoor unit without a communicating control between the indoor unit and the outdoor unit. Method 300 may involve the controller, the indoor unit, the fan drive, the electric heater, the thermostat, the first temperature sensor, the second temperature sensor, the humidity sensor, and other components associated with the system of FIGS. 1A to 2.

Method 300 may include step 302 of monitoring, by the controller, the temperature of air upstream and downstream of the indoor coil associated with the HVAC unit, followed by another step 304 of controlling the speed of the fan(s) configured with the indoor coil based on the temperature monitored at step 302, to maintain a temperature difference across the indoor coil. In one or more embodiments, at step 302, the first temperature sensor and second temperature sensor upstream and downstream, respectively, of the indoor coil may enable the controller to monitor the temperature of air upstream and downstream of the indoor coil, and further determine a real-time temperature difference across the indoor coil.

In one or more embodiments, during a cooling mode of operation of the HVAC unit, method 300 may include step 306 of selecting the predetermined temperature based on the operating environment of an outdoor unit associated with the HVAC unit. In one or more embodiments, the operating environment may be selected from one of a humid condition, a semi-arid condition, and a desert condition. The humid condition may pertain to a first range of humidity, a semi-arid condition may pertain to a second range of humidity, and a desert condition may pertain to a third range of humidity, where the first range may be greater than the second range and the second range may be greater than the third range. In one or more embodiments, during a cooling mode of operation of the HVAC unit, the temperature difference may be selected based on a humidity level. In an example, the humid condition may pertain to a humidity level of 50% or higher, the semi-arid condition may pertain to a humidity level of 25 and 50%, and the desert condition may pertain to a humidity level below 25%. Accordingly, in one or more embodiments, based on the operating environment, the temperature difference to be maintained across the indoor coil for the humid condition, the semi-arid condition, and the desert condition may be 18° F., 21° F., and 24° F., respectively, with a tolerance level of +10%.

In one or more embodiments, at step 306, method 300 may include the steps of monitoring the temperature and/or pressure of refrigerant vapor leaving the indoor coil during the cooling mode and correspondingly determining the operating environment of the HVAC unit.

In one or more embodiments, at step 306, method 300 may include the steps of monitoring superheat control characteristics of an expansion valve associated with the HVAC unit during the cooling mode and correspondingly determining the operating environment of the HVAC unit.

In one or more embodiments, at step 306, method 300 may include the steps of monitoring, using a humidity sensor, specific humidity or relative humidity around an outdoor coil of the HVAC unit and correspondingly determining the operating environment of the HVAC unit based on the monitored humidity.

Further, during a heating mode of operation of the HVAC unit, method 300 may include step 308 of controlling the speed of the fan(s) to maintain a constant temperature difference across the indoor coil, without any adjustment based on the operating environment of the outdoor coil. In addition, in other embodiments, at step 308, method 300 may include the steps of controlling the speed of the fan(s) to maintain a temperature (leaving air temperature) downstream of the indoor coil, instead of maintaining a constant temperature difference across the indoor coil. In such embodiments, the controller may be configured to receive, from the thermostat, data pertaining to the temperature for the air to be supplied to the AOI and accordingly estimate the temperature of the air to be maintained downstream or leaving the indoor coil.

Thus, this disclosure (system and method) addresses the limitations associated with existing communicating controls being employed in HVAC units, by providing an improved HVAC unit that utilizes non-communicating controls to establish coordination between the outdoor and indoor units. As a result, the overall system costs and complexity may be reduced by eliminating the need for communication protocols between the indoor and outdoor units.

In one or more embodiments, the HMI device 122 or thermostat 118 may include an input device comprising one or more of a touchscreen display, a keyboard, and/or a set of buttons for different environmental conditions, but not limited to like. Further, the HMI device 122 or thermostat 118 may include an output device that may include a display device, and a speaker, but not limited to the like.

Although the subject disclosure has been explained considering that system 100 is implemented by the controller 110, it may be understood that the system 100 may also be implemented in a variety of computing systems, such as a laptop computer, a desktop computer, a notebook, a workstation, a server, a network server, a cloud-based environment and the like. The controller 110 comprises one or more processor(s) 110-1 operatively coupled to a memory 110-2. The processors 110-1 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions. Among other capabilities, the processors are configured to fetch and execute computer-readable instructions stored in the memory. The memory 110-2 may store one or more computer-readable instructions or routines, which may be fetched and executed to create or share the data units over a network service. The memory may comprise any non-transitory storage device including, for example, volatile memory such as RAM, or non-volatile memory such as EPROM, flash memory, and the like.

The controller 110 may also comprise an interface(s) that may comprise a variety of interfaces, for example, interfaces for the first and second temperatures sensors, the fan drive 108, the humidity sensor 120, the thermostat 118, and the like. The communication unit of the controller 110 may be a Wi-Fi module, transceiver, Bluetooth module, cellular connection modules such as 2G, 3G, 4G, and 5G, and the like to facilitate communication of the controller 110 with the first and second temperatures sensors, the fan drive 108, the humidity sensor 120, the thermostat 118, and mobile devices associated with users of the subject disclosure, through the network. The interface(s) may also provide a communication pathway for one or more internal components or units of the controller 110. Examples of such internal components include, but are not limited to, processing engine(s) and database.

While the subject disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the subject disclosure as defined by the appended claims. Modifications may be made to adapt a particular situation or material to the teachings of the subject disclosure without departing from the scope thereof. Therefore, it is intended that the subject disclosure not be limited to the particular embodiment disclosed, but that the subject disclosure includes all embodiments falling within the scope of the subject disclosure as defined by the appended claims.

In interpreting the specification, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.