Systems and Methods for Conditioning Unoccupied Premises

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and benefit of U.S. provisional patent application No. 63/646,222 filed May 13, 2024, which is herein incorporated by reference.

FIELD

This disclosure relates generally to climate control systems. In particular, embodiments of the disclosure are related to preconditioning premises that have been unoccupied for long periods of time and making them suitable for occupation.

BACKGROUND

Conventional climate control systems that are used to control climate in large premises, such like office buildings, schools, etc., often have to be left running even when no one is occupying these premises for long periods of time, in order to maintain the climate within these premises. This results in a waste of energy and sub-optimal operation of the climate control system. Accordingly, systems and methods to better manage such situations without having to operate climate control systems for long periods of time in empty premises may be desired.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanying drawings. In some instances, the use of the same reference numerals may indicate similar or identical items. Various embodiments may utilize elements or components other than those illustrated in the drawings, and some elements or components may not be present in various embodiments. Throughout this disclosure, depending on the context, singular and plural terminology may be used interchangeably.

FIG. 1A illustrates an environment in which a climate control system can be implemented according to an embodiment of the present disclosure.

FIG. 1B illustrates a block diagram showing details of the environment in which the climate control system may operate according to an embodiment of the present disclosure.

FIG. 2 illustrates a block diagram of a portion of the climate control system according to an embodiment of the present disclosure.

FIG. 3 illustrates a flow chart of an operation of a climate control system according to an embodiment of the present disclosure.

FIG. 4 illustrates a flow chart of an operation of a climate control system according to another embodiment of the present disclosure.

FIG. 5 illustrates a block diagram of a machine learning system that can be deployed according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

This disclosure relates generally to climate control systems that may be employed in commercial premises or residential units. More specifically, embodiments of the present disclosure relate to systems and methods for conditioning a facility that has been unoccupied for a period of time so that the facility is suitable for human or animal occupation.

There are many instances in which a building or a facility is left unoccupied for long periods of time. For example, a school building is often unoccupied for a long period of time during summer vacations. In some instances, hundreds of thousands of buildings may be unoccupied or sparsely occupied for multiple years. Even in the absence of any such extreme conditions, many buildings are unoccupied regularly for short periods of time. For example, office buildings are often unoccupied during a weekend. Similarly, a lot of residential premises can also be unoccupied for extended periods of time, such as during vacation or a vacation home that gets used only for a small part of the year. In these instances, the climate control systems for these facilities still need to be operational in order to ensure that the facility is in a habitable state if and when it is occupied again.

Currently, in order to maintain the habitability of such facilities, the climate control system is often continually run as if the entire facility is occupied, to maintain a set temperature within the facility and also to prevent build-up of contaminants and carbon dioxide levels within the facility. However, this results in energy waste and increases the cost of operating and maintaining the climate control system. So, there is a need for a solution that would quickly bring a facility that has been unoccupied for a while back into a habitable state without the need for continually operating the climate control system during the periods of non-occupation. The systems and methods described in this disclosure provide solutions to accomplish this, thereby resulting in energy and cost savings and prolonging the usable life of a climate control system.

In describing the disclosed technology, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.

FIG. 1A illustrates an environment in which a climate control system according to an embodiment of the present disclosure can be implemented. Facility 150 can be any commercial or residential facility, such as a school, an office, a single family home, or the like. Facility 150 may include a climate control system 100 that is used to regulate the climate within the facility 150. Climate control system 100 (or any other climate control system described herein) may broadly encompass any system that is configured to heat and/or cool a conditioned space (for example, a commercial establishment or residential building, such as a school, office building, retail establishment, warehouse, single-family home, apartment building, condominium, etc.), heat and/or cool a fluid that is provided to a load, and/or perform any other actions associated with a vapor compression cycle. Non-limiting examples of types of such climate control systems can include air conditioners (e.g., no reversing valve, only provides cooling mode), heat pumps (e.g., air source or geothermal; has a reversing valve and operates in both heating and cooling modes), heat pump water heaters, integrated heat pump water heaters, split system heat pump water heaters, heat pump water heaters with a circulation pump and a brazed plate heat exchanger, split systems, packaged systems, mini-splits, PTACs, window units, vertical packaged systems, VRF systems, etc.

In some embodiments, climate control system 100 may be a residential HVAC unit. The climate control system 100 is in fluid communication with the facility 150 via one more ducts (not shown) that carry air to and from the facility 150. The climate control system 100 is tasked with maintaining the desired temperature and other environmental parameters within the facility 150.

Climate control system 100 includes a control unit 102. Control unit 102 can be a central control unit that controls the operation of climate control system 100. Control unit 102 receives inputs from various subsystems and components of the climate control system 100 and determines the mode of operation of the climate control system. Control unit 102 may include one or more processors, memories, and other peripheral components that together work to control operation of climate control system 100. Control unit 102 may also include a real-time clock (RTC) (not shown) or any other similar device that measures current time and/or that can be programmed to count the passage of time. In an embodiment, control unit 102 may be electromechanical controls or digital controls control board. Control unit 102 may be programmed with specialized firmware to accomplish the systems and methods described herein.

In addition to the memory that may be included in control unit 102, there may be one or more stand-alone memories 104. Memory 104 can be any type of non-volatile memory known in the art. Memory 104 may store instructions that when executed by the one or more processors of control unit 102 enable the climate control system to perform various actions, including but not limited to the systems and methods described in this disclosure. In some embodiments, the memory 104 may store historical data about the operation of the climate control system and the various sensor measurements collected by sensor(s) 106. For example, the memory 104 may store data regarding the last time the fan unit 110 was operated, sensor data measured during a specific period of time, etc.

Climate control system 100 may further include one or more sensors 106. These sensors may include sensors that monitor one or more environmental parameters such as humidity, carbon dioxide (CO₂) levels, volatile organic compounds (VOC) levels, smoke, air quality, etc. Sensors 106 may also include temperature, pressure, leak, and other similar types of sensors that measure the performance of climate control system 100. Sensors 106 can send their measurement data to control unit 102 and this data may be stored for later usage in the memory 104. Sensors 106 may be located within the facility and external to the facility. For example, a humidity or CO₂ sensor may be located inside the facility while an air quality measurement sensor may be located outside the facility or mounted to an external surface of the facility to measure the air quality of outside ambient air.

Climate control system 100 may also include a communication interface 108. Communication interface 108 may be any suitable wired or wireless communication interface known in the art. Communication interface 108 can relay data from the climate control system to an external system, such as a central control system for a building or a facility. Communication interface 108 can also receive data from an external system, such as a central control unit of a building that is configured to control the operation of the climate control system 100. In some embodiments, communication interface 108 may communicate with other climate control systems within a single facility or across multiple facilities. For instance, a control server may be configured to monitor and operate multiple climate control systems and all these climate control systems may be communicably coupled to each other, such as via their individual communication interfaces 108.

Climate control system 100 may also include a user interface 126. User interface 126 may include a touch screen display or some other type of audio or video input and output elements that enable a user to interact with climate control system 100. In an embodiment, user interface 126 may include one or more input mechanisms (e.g., touch screen, keyboard, microphones, camera, etc.) for inputting desired values for CO₂ levels in the facility, humidity levels in the facility, or total volatile organic compounds (TVOC) levels in the facility. User interface 126 may include one or more output mechanisms, such as display, speaker, haptics, etc. that provide some form of audio, visual or tactile output. User interface 126 may be accessible from outside the facility in some embodiments.

Climate control system 100 may also include one or more fans 110. Fan(s) 110 controls the airflow for the climate control system. Fan 110 can draw the air from within the facility and direct that air over one or more heat exchangers, such as evaporator 114 or condenser 118. This air is then transported to the outside of the facility depending on the operation mode of the climate control system 100. Another fan 110 may draw in the ambient outside air and direct that air over the one or more heat exchangers to either heat or cool the air based on the mode of operation of climate control system 100. This air is then directed to the inside of the facility. Operation of fan 110 is well-known in the art. In some embodiments, fan 110, along with other components such as filters and the one or more heat exchangers, etc. may be packaged inside an air handling unit. Such an air handling unit is normally installed on the roof of the facility, basement of the facility, or within the facility and may serve one single portion or multiple portions of the facility.

Climate control system 100 also includes one or more compressors 112. Compressor 112 compresses a fluid, such as a refrigerant, into a high pressure-high temperature vapor form and circulates that fluid throughout the climate control system. The fluid is ultimately returned to the compressor in a low-pressure vapor form. Compressor 112 can be realized using any known compressor in the art. In some embodiments, only a single compressor may be present. In other embodiments, multiple compressors, such as tandem scroll compressors, are employed for greater efficiency and reliability. The systems and methods described in this disclosure are equally applicable regardless of the number of compressors used in the climate control system 100.

Climate control system 100 may also include an evaporator 114. Evaporator 114 is a type of heat exchanger where the refrigerant liquid is circulated and warm air is traversed across the evaporator 114, such as by using fan 110. The refrigerant liquid is converted to gas by absorbing heat from the air that is traversed over the evaporator. Evaporator 114 can be realized using any known device in the art. For example, evaporator 114 may be an air cooled heat exchanger, shell and tube heat exchanger, plate heat exchanger, or the like.

Climate control system may also include a condenser 118. Condenser 118 performs a function that is the opposite of evaporator 114. Condenser 118 is also a type of heat exchanger and may receive the refrigerant in a high-pressure gas form from the compressor and converts this gas to a slightly cooled liquid form. In an embodiment, fan 110 may blow cold air over condenser 118. The refrigerant inside the condenser 118 transfers some of its heat to the cold air and in the process cools down. Condenser 118 can be realized using any known device in the art. For example, condenser 118 can be realized using an air cooled heat exchanger, shell and tube heat exchanger, plate heat exchanger, or the like.

While the evaporator 114 and condenser 118 are described as separate components above, in heat pump systems, the same component may be operated as the evaporator 114 or condenser 118 depending on the operating mode of the climate control system 100. For example, a first heat exchanger in fluid communication with the indoor environment of the facility 150 (e.g., placed indoors or connected to the indoors via one or more ducts) may be operated as the evaporator 114 in a cooling mode or the condenser 118 in a heating mode. Likewise, a second heat exchanger in fluid communication with the outdoor environment surrounding the facility 150 (e.g., placed outdoors or connected to the outdoors via one or more ducts) may be operated as the condenser 118 in the cooling mode or the evaporator 114 in the heating mode.

Climate control system may 100 also includes a thermostat 116. Thermostat 116 is a control unit that is used to regulate temperature in the climate control system 100. Thermostat 116 may include a user interface via which a user can input set points for desired temperature, humidity, etc. in the facility. Depending on these set points, thermostat 116 can instruct other subsystems of climate control system 100 to perform the appropriate operation (e.g., heating, cooling, etc.). Thermostat 116 can be realized using any known devices in the art. In various implementations, more than one thermostat 116 may be positioned within the facility for establishing separate zones of climate control.

Climate control system may 100 also include an economizer 120. The climate control system may use the economizer 120 to ingest outdoor air into the facility instead of operating the compressor. Economizer 120 ingests outdoor air and optionally mixes it with air from indoors. This results in more efficient operation of the climate control system 100. Economizer 120 may include an additional fan to help draw in the outside air. In various implementations, the economizer 120 may be implemented as a heat recovery module (HRV) or energy recovery module (ERV) for exchanging heat and/or moisture between incoming and outgoing streams of air.

Climate control system 100 may also include refrigerant lines 122 that carry the refrigerant throughout the system and ductwork 124 to circulate air within the facility by transporting air from within the facility to the outside and transporting air from outside to within the facility. In various implementations, the ductwork 124 may include one or more dampers for differentially controlling airflow to different locations within the facility.

It is to be noted that climate control system 100 is just one example and other climate control systems may include more or less components than what is shown in FIG. 1. Although climate control system 100 described above is akin to an Air Source Heat pump system, the systems and methods described below are equally applicable to other types of climate control systems, such as air-to-water heat pump system, ground source heat pumps, hybrid heat pumps, ductless mini-split heat pumps, absorption heat pumps, hydronic boilers, electric heaters, electric storage heaters, solar heaters, split air conditioners, etc. One skilled in the art will realize that there may be other ways to realize climate control system 100 without departing from the functionality described above.

FIG. 1B illustrates additional details of the environment in which the climate control system 100 may be deployed according to an embodiment of the present disclosure. As noted above, climate control system 100 may be deployed in commercial or residential facilities. As noted above, facility 150 may be a commercial facility like an office building, retail establishment, a school, or the like. In some embodiments, facility 150 may be a single family home, a multi-unit dwelling, or the like. Facility 150 may have one or more rooms or sections 152. Sensor(s) 106 may be deployed in one or more of the rooms or sections 152. In some embodiments, each room or section may include all of the available sensors 106. In other embodiments, specific sensors may be placed at specific locations within the facility 150. In some embodiments, the amount and location of the sensor(s) 106 may be governed by local building and other relevant codes. Similarly, thermostat(s) 116 may be deployed in or more of the rooms or sections 152.

Facility 150 may have a portion of the climate control system 100 mounted on the roof. In other embodiments, portions of the climate control system may be installed in the basement or one or more floors of the facility 150. The specific location of the climate control system 100 is not germane to the systems and methods disclosed herein. As shown in FIG. 1B, climate control system 100 may include an air intake unit 162 and an air output unit 160. In some embodiments, air intake unit 162 and air output unit 160 may each be part of an air handling unit. In some embodiments, air intake unit 162 draws in fresh air from outside the facility and mixes that air from within the facility. In other embodiments, the air from within the facility is not mixed with the outside air ingested by the air intake unit 162. In the set up illustrated in FIG. 1B, the economizer 120 is located within air intake unit 162. In some embodiments, an air quality measurement sensor 170 may be coupled to the climate control system 100 to monitor the quality of the outside air. In an embodiment, the air quality measurement sensor 170 may be an air quality index measurement sensor. Air intake unit 162 may have other components of the climate control system 100, but not all those components are shown in FIG. 1B. The air output unit 160 draws air from within the facility and expels that air to the outside environment. In some embodiments, a portion of the air drawn from within the facility may be mixed with or otherwise have heat and/or moisture exchanged between the air being provided by the air intake unit 162. Both the air intake unit 162 and the air output unit 160 are in fluid communication with their respective ductwork 124a and 124b in order to supply air to and draw air from within the facility as is shown by the directional arrows in FIG. 1B.

In operation, whenever fresh air from outside is needed, economizer 120 may operate in conjunction with fan 110 to draw the outside air and optionally mix it with the inside air in order to implement the conditioning systems and methods mentioned in this disclosure, to remove the stagnant air from within the facility 150 and replace it with fresh air from outside the facility 150. The following figures and description will provide the details of these various systems and methods.

FIG. 2 is a block diagram of a portion of a climate control system 200 according to an embodiment of the present disclosure. Climate control system 200 may be similar to climate control system 100 described above.

Climate control system 200 includes control unit 102. Control unit 102 may include one or more processors or controllers that control the operation of the climate control system 200. The one or more processors or controllers may be programmed with custom firmware that executes the functions described below. Climate control system 200 includes a heating subsystem 202 that may include several components and is functional to provide heating to the facility. Heating subsystem 202 may include a fan, one or more heat exchangers, and a compressor and associated refrigerant lines. Climate control system 200 further includes a cooling subsystem 204 that may include several components and is functional to provide cooling to the facility. For example, cooling subsystem 204 may include a compressor, a fan, one or more heat exchangers, and associated refrigerant lines. Heating subsystem 202 and cooling subsystem 204 may also share some components, such as one or more compressors, one or more heat exchangers in a heat pump system, etc. In an embodiment, fan(s) 110 may be part of the heating subsystem 202 or the cooling subsystem 204. Control unit 102 is electrically coupled to both heating subsystem 202 and the cooling subsystem 204 and controls the operation of these two subsystems.

Control unit 102 is also electrically coupled to the economizer 120. As described above, economizer 120 is in fluid communication with the ambient environment via one or more ducts. When economizer 120 is activated, it draws in ambient air from outside the facility and mixed it with air from within the facility. The operation of economizer 120 is controlled by the control unit 102. Control unit 102 is also electrically coupled to the thermostat 116. Thermostat 116 allows an operator to set temperature and other set points. This set point information is provided to the control unit 102, which then operates either the heating subsystem 202 or the cooling subsystem 204 in order to achieve the temperature set point.

Control unit 102 is also electrically coupled to the sensor(s) 106. A particular facility may employ multiple sensors that each measure some specific parameter of the environment within the facility or external to the facility. As described above, sensor(s) 106 may include CO₂, humidity, VOC, smoke, air quality, and other similar sensors. Sensors 106 are configured to send their respective measurement data to the control unit 102. Sensors 106 may send the measurement data periodically or on demand. In an embodiment, sensors 106 may be Internet of Things (IoT) based sensors that can communicate wirelessly with control unit 102.

In an embodiment, control unit 102 receives input from sensors 106 and thermostat 116 and based on those inputs controls operation of the climate control system 100 in order to maintain the facility in a habitable state. The different methods of conditioning the environment within the facility after a prolonged time of non-occupation are described below in relation to FIGS. 3 and 4.

FIG. 3 illustrates a flow chart for a process 300 for operating a climate control system (e.g., climate control system 100 of FIGS. 1A, 1B, or 2) according to an embodiment of the present disclosure. The following description will be provided with reference to both FIGS. 2 and 3.

As described above, certain facilities may remain unoccupied for extended periods of time. For example, a school building may remain unoccupied for the entire duration of summer holidays. Normally, the climate control system of such a facility may be left on or run periodically using a set schedule, such as daily or weekly, in order to maintain the habitability of the building. However, in order to conserve energy and lower costs, the climate control system of such a facility may be turned off or kept idle during that non-occupation time period. While turning off the climate the control system may save money, undesirable environmental conditions such as humidity, CO₂ level, or VOC levels may increase within this facility since the air within the facility is sitting stagnant for an extended period of time. Before such facility is cleared for human occupation, it is desirable that the stagnant air within this facility be removed and replaced with fresh air and the various environment parameters be brought within their respective acceptable ranges. In other words, a conditioning of the facility may be needed in order to maintain the facility habitable. If the climate control system has been idle or non-working for an extended period of time, it may take a long while before the facility can be made habitable again once the climate control system is made operational. Currently, the climate control system of such a facility is kept active continually to avoid the long recovery time that may be needed. So, in many instances, the climate control system is heating or cooling an empty facility. To avoid the issues caused by continually running the climate control system or completely shutting down the climate control system for long periods of time, the systems and methods disclosed herein provide an alternative that is cost effective to operate, saves energy, and may prolong the usable life of the climate control system.

FIG. 3 illustrates a process 300 for conditioning of the facility according to an embodiment of the present disclosure. Conditioning as used herein refers to the process of replacing the stagnant air within a facility that has been unoccupied for a while, with fresh air and to ensure that the environmental parameters, such as temperature, humidity, TVOC levels, CO₂ levels, etc. within the facility are within their respective acceptable ranges as described above. At operation 302, process 300 may be activated. Activation of process 300 may be manual or automatic depending on the status of one or more parameters. At operation 304, the climate control system 100 determines the amount of time elapsed since the last operation of the system. For example, climate control system 100 may determine the time elapsed since the last time the fan was operated. Other criteria for “last operation” may also be used and an operator of climate control system 100 can decide what criteria is to be used. In an embodiment, the RTC in control unit 102 may be used to determine the amount of time elapsed since the last operation of the climate control system 100. In another embodiment, the timer in control unit 102 may be used to keep track of elapsed time since last operation. In some embodiments, the operator of climate control system 100 may configure the maximum amount of time that climate control system 100 is allowed to remain idle/turned off. For example, the operator may set X hours or X days or any other suitable measure as the maximum duration for which climate control system 100 is allowed to be idle/turned off. In other embodiments, this time value may be hard-coded into the system.

At operation 306, the climate control system 100 determines whether the time elapsed since the last operation of the climate control system 100 exceeds the set value. If the time elapsed since the last operation of the climate control system 100 does not exceed the set value, process 300 returns to operation 304 and the time monitoring continues. If it is determined that the time elapsed since the last operation of the climate control system 100 exceeds the set time value, process 300 proceeds to operation 308. It is to be noted that time elapsed since the last operation is not the only parameter that can be used to trigger the following operations. Other parameters in lieu of or in addition to time elapsed can also be used to trigger the operations. For example, time of the day, day of the week, time before scheduled re-occupation of the facility, presence of humans in the facility, etc. may also be used. In other embodiments, if one or more of the environmental parameters are found to be out of their respective acceptable ranges based on the sensor data, the climate control system may initiate the process 300. Time elapsed since the last operation of climate control system 100 is used herein just for the sake of explanation and the systems and methods described herein are not limited to use of this parameter only.

At operation 308, the climate control system 100 receives data from the one or more environment sensors, such as sensors 106 of FIG. 2. This data is compared against a threshold value for each of the respective parameters. As explained above, various types of environmental sensors may be used in the system. For example, the system may use a carbon dioxide (CO₂) sensor. The acceptable carbon dioxide levels for a habitable facility is prescribed by the relevant building code based on the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards. In one embodiment, the maximum acceptable indoor carbon dioxide levels are between 1000 ppm and 1500 ppm. It is to be noted that the range specifies the upper limit of the level of carbon dioxide. So, as long as the levels of carbon dioxide are lower than 1500, it can be considered to be acceptable. In this instance, the data received from the carbon dioxide sensor is analyzed to determine whether the data is within the acceptable range. In case of a humidity sensor, the acceptable indoor humidity may be in the range of 40% to 60%. Therefore, data received from a humidity sensor is compared against this range. In the instance where total volatile organic compounds (TVOC) are being monitored, the following Table 1 below may be used to determine whether the data received from the TVOC sensor(s) are within the level of acceptable values for VOCs. In one instance, the acceptable TVOC levels may be prescribed by one or more industry organization or standards such as Occupational Safety and Health Administration (OSHA), Leadership in Energy and Environmental Design (LEED), World health Organization (WHO), etc. In Table 1 below, the “Description” column generally describes the quality of the environment inside the facility in a textual form that is easy to understand. “Index value” refers to the TVOC index that is commonly known in the art. The final column “TVOC (ppb*)” includes values that are represented in parts per billion (ppb) and refers to amount of VOC particulate matter in a given space. Total volatile organic compounds (TVOC) is a group of VOCs used to represent the entire pool of pollutants.

It is to be noted that the acceptable levels of the environmental parameters may vary according to the geographic location, as different countries may have different standards. The ranges and values provided above in Table 1 are just one example of what the acceptable levels may be and should not be construed as binding or the only acceptable values.

In some embodiments, prior to receiving the sensor values at operation 308, the climate control system 100 may turn on a fan associated with the climate control system 100 for a specified period of time to circulate the indoor air. Once the fan has been operated for the specified period of time, control unit 102 may receive the data from the sensors. In some embodiments, control unit 102 may be programmed to “pull” data from the sensors after expiry of the specified period of time. In other embodiments, the sensors may be instructed to send their data at a specific time which coincides with the expiry of the specified period of time. This specified period of time may be hard-coded into the system or may be user-programmable. This specified period of time is usually lower than the period of time for which the climate control system 100 is allowed to remain idle/non-operational as explained with relation to operations 304 and 306 above.

At operation 310, climate control system 100 analyzes the data received in operation 308 to determine whether data from one or more of the sensors indicates that the corresponding environmental parameter is out of range. For example, data from a carbon dioxide sensor might indicate that the level of carbon dioxide within a portion of the facility or even within the entire facility is higher than the maximum acceptable value described above. Alternatively, data from the carbon dioxide sensor may indicate that the level of carbon dioxide in the facility are lower than the maximum acceptable value. If at operation 310, the control unit determines that all of the sensors indicate that the respective parameters are within their respective acceptable ranges, process 300 may return to operation 304 (or optionally to operation 308) and continue receiving sensor data and comparing that against the respective thresholds.

If at operation 310, the control unit determines that one or more sensors indicate that the corresponding environmental parameter is higher than the respective acceptable range, the system may proceed to operation 312. The climate control system 100 may be programmed in multiple ways to interpret and react to the data provided by the sensors. For example, the system may be programmed such that even if a single sensor indicates that a single environmental factor is higher than the corresponding acceptable range, system may execute operation 312. For instance, even if only the CO₂ sensor may indicate that the indoor CO₂ value is higher than the acceptable range while the TVOC and humidity sensors may indicate values within their respective acceptable ranges, the system may proceed to operation 312. In other embodiments, the system may be programmed to proceed to operation 312 only if two or more sensors show that their data indicates that the environmental parameters are higher than their corresponding acceptable ranges. One skilled in the art will realize that there are many more ways of programming the system to act based on several different combinations of the sensor data. All of these different combinations are within the scope of this disclosure, but are not explicitly described herein for sake of brevity.

Once it is determined that one or more sensors indicate that the corresponding environment parameter is out of acceptable range, the climate control system may operate to ingest air from outside the facility at operation 312. In one embodiment, the control unit of the climate control system may operate economizer 120 to facilitate flow of outside air into the facility. Economizer may turn on an associated fan, open the dampers, and draw in ambient air from outside the facility. This outside air is then optionally mixed with the indoor air and then recirculated within the facility. Other portions of the climate control system may also be activated to work in conjunction with the economizer to continually circulate the outside air within the facility and remove the stagnant from within the facility. In due course, the environmental parameters may slowly start to return to acceptable levels.

Once the outside air is ingested at operation 312, the system may monitor the temperature set point for the facility at operation 314. In one embodiment, the operator of the facility may designate an indoor temperature set point for the facility when the facility is unoccupied. In one instance, this temperature set point may be lower than the temperature set point when the facility is occupied. For example, the temperature set point for an unoccupied facility may be set at 60° F. while the temperature set point for that same facility when it is occupied may be set at 68° F. These temperature set points may vary based on geographic area and the average outside ambient temperature patterns in that geographic area. As the outside air is ingested into the facility the temperature inside the facility may rise or fall depending on the temperature of the ambient outside air. The climate control system continually monitors the current temperature inside the facility, at operation 316, and compares that to the current temperature set point.

At operation 316, the system determines whether the current temperature within the facility is higher or lower than the temperature set point. If the current temperature is higher than the temperature set point, the system may initiate a cooling operation at operation 318, such as by operating the cooling subsystem 204. If the current temperature is lower than the temperature set point, the system may initiate a heating operation at operation 320, such as by operating the heating subsystem 204. The process 300 may repeat until all the environmental parameters are within their respective acceptable ranges and the indoor temperature is substantially equal (e.g., within +−5%) to the temperature set point. Optionally, after starting the cooling operation at operation 318 or the heating operation at operation 320, the climate control system may cease operation of the economizer and stop ingesting outside ambient air. Whether to stop the operation of the economizer may depend on several factors including the current levels of environmental parameters as measured by the one or more environmental sensors.

Further, after initiating cooling operation at operation 318 or heating operation at operation 320, process 300 may return to operation 308 and continue monitoring the various sensors to determine whether the corresponding environmental parameters are within the acceptable ranges. If the values of the environmental parameters are still out of range, the system may continue to ingest outside air (operation 312) and the process is repeated until one or more of the environmental parameters come within their acceptable range. Once the sensors indicate that the environmental parameters are within the respective acceptable ranges, the climate control system 100 may stop ingesting the outside air. In this manner, the system ensures that the facility is always ready to be occupied and the environment within the facility does not become hazardous.

FIG. 4 illustrates a process 400 for operating a climate control system according to another embodiment of the present disclosure. Process 400 may be performed, for example, by climate control system 100 of FIGS. 1A-1B or 2.

At operation 402, process 400 may be triggered, such as based one or more criteria explained above with reference to FIG. 3. At operation 404, the climate control system determines an amount of time elapsed since the last operation of the climate control system. As explained above, this is just one of the many parameters that can be used to trigger process 400. At operation 406, the climate control system determines whether the time elapsed since the last operation is more or less than a threshold value. The time elapsed value may be measured in minutes, hours, days, weeks, or months. The threshold value is also set accordingly. In an embodiment, the threshold value may be set by the user based on the usage pattern or usage history of the facility. In other embodiments, the threshold value may be dynamically adjusted based on the outside ambient temperature. For example, consider that initially the threshold time setting for time elapsed since the last operation is set at two days. A current time indicates that it has been less than two days since the last operation, so process 400 should not be triggered. However, outside ambient temperature data indicates that the outside ambient temperature exceeds a threshold, such as 100° F. In this instance, the system may dynamically modify the threshold time setting such that process 400 is initiated before the expiration of two days since the last operation. Thus, the outside ambient temperature may be used to trigger the process 400 even if the result of the check at operation 406 is a ‘no.’ Similarly, other events may be used to trigger process 400 even if the results of the check at operation 406 indicate that the process 400 should not move forward beyond operation 406.

If at operation 406, it is determined that the time elapsed since the last operation is less than the threshold value, the climate control system stays in its current mode and process 400 returns to operation 404 and continues counting the time elapsed, such as by using the RTC in the control unit 102, as explained above. As soon as the climate control system determines that the time elapsed since the last operation is equal to or greater than the threshold value (or is otherwise triggered by other events described above), process 400 may move to the next operation 408. As described above, in some embodiments, prior to moving on to operation 408, the climate control system may operate a fan for a specified period of time after determining that the time elapsed since the last operation is more than the threshold value.

At operation 408, the data received from one or more of the environmental parameter sensors is analyzed by the climate control system. In some embodiments, the data from the sensors may only be requested after the determination in operation 406 that the time elapsed since the last operation is more than the threshold value. In other embodiments, the sensors may be programmed to continually or periodically send their data to the control unit. This data may be saved in a circular buffer where the most recent values overwrite the oldest value. Then, once the determination is made in operation 406 that the time elapsed since the last operation is more than the threshold value, the most recent values in the buffer are read and compared against the respective thresholds. One skilled in the art will realize that there are many other ways to implement this operation.

Once the most recent data from the one or more sensors is received at operation 408, process 400 proceeds to compare the data with the respective thresholds or ranges at operation 410. If the sensor data indicates that the environment parameters are within their respective acceptable ranges or below the thresholds, process 400 may return to operation 404 or optionally to operation 408 and continue monitoring the sensor data. It is to be noted that in this case, even if the time elapsed since the last operation is more than the threshold value, the system may still remain in its current idle state since the environmental parameters are within range. Thus, the system may be programmed to prioritize to operate the economizer only if one or more environmental parameters exceeds the respective threshold.

If at operation 410, the climate control system determines that one or more of the environmental parameters have exceeded their threshold, process 400 moves to operation 412. At operation 412, the climate control system determines the quality of the outside air. In one embodiment, an externally placed air quality sensor, such as an air quality index (AQI) sensor, may provide the data related to the quality of the outside air. For example, it may be the case that while the indoor environmental parameters are out of acceptable range, the outside air may be worse in quality than the current indoor air. Consider a situation where there is a wildfire in progress near the facility. In that situation, the outside air quality may be significantly worse than the indoor air quality. If such outdoor air is ingested into the facility, it may further worsen the quality of the indoor air and may render the facility uninhabitable for a longer duration of time. In such situations, it may be prudent to not ingest the outside air and wait until the outside air quality improves.

Accordingly, in process 400, at operation 412, the system checks whether the outside air quality is better or worse than a threshold air quality value. This threshold air quality value can be set by the system operator based on historical data for the geography in which the facility is located. In one embodiment, the threshold air quality value may be expressed in terms of an AQI value. The lower the AQI, the better the air quality. So, in this instance, if the outside air quality is better than the indoor air quality (e.g., outside air AQI value is lower than the threshold AQI value), process 400 ingests the outside air at operation 414. If the outside air quality is worse than the indoor air quality (e.g., outside air AQI value is higher than the threshold AQI value), the system may not ingest the outside air and process 400 returns to operation 402. This cycle repeats until the outside air quality improves. In this instance, even if the time elapsed since the last operation of the system is greater than the corresponding threshold value (operation 406) and the sensor values indicate that the indoor environmental parameters are out of acceptable ranges (operation 410), the system may still not ingest outside air if the outside air quality is worse than the outside air quality threshold.

If at operation 414, the climate control system determines that the outside air quality is good (i.e., outside air AQI value is lower than the threshold AQI value), the climate control system may operate the economizer to ingest the outside air into the climate control system. Once the outside air starts circulating and optionally mixing with the inside stagnant air, the one or more environmental parameters may slowly start getting back below their respective maximum thresholds or within their respective acceptable range. The climate control system determines the temperature set point data for the facility at operation 416. For example, the temperature set point may be determined from a thermostat coupled to the climate control system.

At operation 418, the temperature set point is compared to the current temperature within the facility. For example, one or more temperature sensors may be deployed within the facility. These sensors may send the current temperature data to the control unit. If the current temperature within the facility is higher than the temperature set point, the climate control system may initiate a cooling operation at operation 422. For example, the cooling subsystem 204 may be activated to cool down the air within the facility. If at operation 418, it is determined that the current temperature inside the facility is lower than the temperature set point, the climate control system may initiate a heating operation at operation 420. For example, the heating subsystem 202 may be activated to heat the air in the facility. In either instance, whether the cooling operation or the heating operation is initiated, process 400 returns to operation 408 where it continually receives data from the one or more environmental sensors.

Once the one or more environmental sensors indicate that most or all of the environmental parameters are within acceptable limits (i.e., “no” at operation 410), climate control system my return to idle mode, cease operation of the economizer, and return to operation 404. It may reset the time elapsed since the last operation to zero and start the timer or use the RTC to monitor the time elapsed again. In other embodiments, once the one or more environmental sensors indicate that most or all of the environmental parameters are within acceptable limits, the system may stop ingesting outside air but continue to monitor the internal temperature of the facility (i.e. operation 418) and run the heating or cooling operations accordingly while also continually monitoring the environmental sensors at operation 408.

In some embodiments, the system can be set up in a manner to make it more efficient and cost-effective to operate. For example, based on the schedule of occupancy and non-occupancy times of the facility, the system can be programed to run processes 300 or 400 at times when the energy costs are lower. For example, process 300 or 400 may be run during night when electricity costs are lower (e.g., off-peak hours) thereby lowering the overall operating costs of the system.

In some embodiments, the system may also include an occupancy sensor that detects when the facility is occupied and when it is empty. For example, continuing the school example from above, the climate control system 100 can learn a pattern of occupancy of the school building based on historical data from the occupancy sensor. Based on the occupancy data, the climate control system 100 may determine days and times of likely occupancy of the school building (e.g., weekdays between 7 AM and 4 PM). Based on this knowledge, the climate control system 100 may automatically enable process 300 (or process 400) in order to ensure that the school building is at a habitable level before a predicted occupancy day and time. For example, if the occupancy data indicates that the school building is occupied between the hours of 7 AM and 4 PM every week day, the climate control system 100 may run process 300 or 400 at 5 AM every week day to ensure that the building is ready for occupancy by 7 AM. Over the weekend, the climate control system 100 may go into idle mode to conserve energy and costs. Thus, climate control system 100 can be a smart system that not only ensures optimal climate conditions for a facility but also helps to minimize energy consumption and lowers operating costs.

In some embodiments, in addition to the environmental sensors that monitor the indoor air quality within the facility 150, the climate control system 100 may also include one or more refrigerant leak sensors that monitor refrigerant leak inside the climate control system 100. In one embodiment, the refrigerant leak sensors can be an A2L refrigerant leak sensor. In one embodiment, the refrigerant leak sensor can be a heated diode type leak sensor, an ultrasonic leak sensor, or an Infrared leak sensor. One skilled in the art will realize that other suitable refrigerant leak sensors may also be used.

The refrigerant leak sensor may continually monitor for refrigerant leaks in the climate control system 100 when it is idle, such as during the non-occupancy of the facility 150, and during the time when the climate control system 100 is operating. If the one or more refrigerant leak sensors detect a refrigerant leak in any portion of the climate control system 100, a signal may be sent to the control unit 102. The control unit 102, upon receiving the signal, may perform one or more of the following actions to provide positive ventilation within the facility 150 to alleviate the effects of the refrigerant leak. In one instance, the control unit 102 may operate the economizer 120 to ingest outside air into the facility 150 and circulate that outside air within the facility 150. In conjunction with the economizer 120, the climate control system 100 may also cause or operate a power exhaust system to draw the inside air via a return air duct and expel that air to the outside of the facility 150.

In another instance, the facility may have one or more third party exhaust fans or systems installed that are separate from the climate control system 100. In this instance, the control unit 102 may also communicate with the respective control system of such third party exhaust fans or systems to cause them to operate in order to remove the air from within the facility 150. In addition to removing the air from within the facility 150, the climate control system 100 may also provide a notification associated with the refrigerant leak. This notification may be in the form of an audio output, a visual output, or both. Such notification may be provided via the output mechanism of the climate control system 100 or via any other suitable device associated with the operator of the facility 150. It is to be noted that the above actions may be performed in conjunction with the operations described with respect to process 300 and process 400 above.

In one embodiment, the climate control system may employ machine learning processes to automate the operation of the climate control system and make the climate control system adaptive. FIG. 5 illustrates a block diagram of a machine learning system 500 according to an embodiment of the present disclosure. The machine learning system may be implemented in the control unit 102 of the climate control system 100 in one embodiment. In other embodiments, the machine learning system 500 may be implemented separately from the climate control system and the output data 512 of the machine learning system 500 may be used to operate the climate control system 100.

The machine learning system 500 includes a learning algorithm logic 502. In one embodiment, the learning algorithm logic 502 accepts training data 504 and generates a machine learning model 506. The learning algorithm logic 502 can be any of the commonly known algorithms such as linear regression, logistics regression, decision tree, artificial neural network, k-nearest neighbors, k-means, and the like. The training data 504 can include various types of data such as the time it takes for the various environmental parameters to rise to levels that are outside of their individual acceptable ranges in an unoccupied facility, the average time of non-occupancy of the facility throughout the year, details associated with the operational parameters of the climate control system, time needed to bring back the various environmental parameters within range once the climate control system starts operating from their measured values prior to the operation of the climate control system, average idle time of the climate control system on a per day, per month, or per year basis, time needed to bring the inside temperature of the facility to within the desired set point range once the outside air ingestion is initiated, the average ambient outdoor temperatures on a daily, monthly, or yearly basis, current and future weather data, etc. In addition, the learning algorithm logic 502 may also receive data that shows the change in the values of the environmental parameters as a function of time while the climate control system is operating. Based on the above data, the learning algorithm logic 502 may generate the machine learning model 506. The learning algorithm logic 502 may include an objective function 510. The objective function 510 quantifies and optimizes the performance of the machine learning model 506.

The machine learning model 506 uses the learnings generated by the learning algorithm logic 502 to generate a set of rules and procedures that can be used to make a prediction or generate a set of instructions that can be provided to the climate control system 100. For example, based on the data received from the learning algorithm logic 502, the machine learning model 506 may output specific instructions, such as operating the climate control system for a specific period of time, capturing data from the environmental sensors at specific intervals, etc. In addition, the machine learning model 506 may also receive the current sensor data 508 from the various environmental sensors described above. The machine learning model 506 than uses the current sensor data 508 along with the data received from the learning algorithm logic 502 and determines a set of actions to be taken as output 512. The set of actions can include, for example, a time period for which to run the climate control system. When the climate control system is operated based on the output 512 from the machine learning model 506, the results of the operation are provided to the learning algorithm 502 to check whether the predictions of machine learning model are valid. For example, based on the current CO₂ level data in the facility received from the CO₂ sensor and the information received from the learning algorithm logic, the machine learning model estimates that the climate control system should be operated for 10 mins to bring the CO₂ levels within the acceptable range. After 10 mins of operation, the CO₂ data is collected to determine whether the 10 mins of operation was sufficient to bring the CO₂ levels within the acceptable range as predicted by the machine learning model 506. If the CO₂ levels are not within range, this information is then used by the learning algorithm logic 502 to further refine its output. In this instance, the machine learning model 506 is updated to account for this behavior. For example, the machine learning model 506 may be updated to extend the period of operation to 15 mins, the next time a similar level of CO₂ is detected. Thus over a period of time, the entire system is optimized such that the climate control system is run in an efficient manner. The learning algorithm 502 may be trained using the supervised or unsupervised learning methods depending on the training data 504.

Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or substantially” another particular value. When such a range is expressed, the disclosed technology can include from the one particular value and/or to the other particular value. Further, ranges described as being between a first value and a second value are inclusive of the first and second values. Likewise, ranges described as being from a first value and to a second value are inclusive of the first and second values.

Herein, the use of terms such as “having,” “has,” “including,” or “includes” are open-ended and are intended to have the same meaning as terms such as “comprising” or “comprises” and not preclude the presence of other structure, material, or acts. Similarly, though the use of terms such as “can” or “may” are intended to be open-ended and to reflect that structure, material, or acts are not necessary, the failure to use such terms is not intended to reflect that structure, material, or acts are essential. To the extent that structure, material, or acts are presently considered to be essential, they are identified as such.

It is also to be understood that the mention of one or more operations does not preclude the presence of additional operations or intervening operations between those operations expressly identified. Moreover, although the term “operation” can be used herein to connote different aspects of methods employed, the term should not be interpreted as implying any particular order among or between various operations herein disclosed unless and except when the order of individual operations is explicitly required. Further, the disclosed technology does not necessarily require all operations included in the methods and processes described herein. That is, the disclosed technology includes methods that omit one or more operations expressly discussed with respect to the methods described herein.

It should be apparent that the foregoing relates only to certain embodiments of the present disclosure and that numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the disclosure.

Although specific embodiments of the disclosure have been described, numerous other modifications and alternative embodiments are within the scope of the disclosure. For example, any of the functionality described with respect to a particular device or component may be performed by another device or component. Further, while specific device characteristics have been described, embodiments of the disclosure may relate to numerous other device characteristics. Further, although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments. Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments could include, while other embodiments may not include, certain features, elements, and/or operations. Thus, such conditional language is not generally intended to imply that features, elements, and/or operations are in any way required for one or more embodiments.