Patent Publication Number: US-2023151996-A1

Title: Device and method for recovering thermal energy in room

Description:
BACKGROUND 
     1. Field 
     The disclosure relates to an electronic device and an operating method thereof. More particularly, the disclosure relates to a method, performed by an electronic device, of recovering heat remaining in a room, and the electronic device. 
     2. Description of Related Art 
     Recently, eco-friendly technologies related to energy reuse have been developed due to climate change. More specifically, there is a need for technology capable of reducing wasted energy by reusing or recycling unused energy. 
     In addition, with the growing interest in the residential environment, facilities for an air conditioning system are increasing in each space to keep the air in the house comfortable. For example, in each room of the house, an air outlet and an air inlet are provided, and an air conditioner, an air quality sensor, etc., are provided. 
     Thus, a method of utilizing wasted energy in a room using such an air conditioning facility is required. 
     SUMMARY 
     Aspects of embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of embodiments. 
     According to an embodiment, an air conditioning control device may include a ventilation fan; a memory storing at least one instruction; and at least one processor configured to, by executing the at least one instruction: (a) determine, among a plurality of rooms, a first room from which thermal energy is to be recovered and a second room to which the thermal energy to be recovered is to be supplied, based on at least one of a sensor value of a sensor in a room among the plurality of rooms, a use schedule of at least one room among the plurality of rooms, and a user input, and (b) drive the ventilation fan to suck air of the first room through an air outlet of the first room, to suck air of the second room through an air outlet of the second room, to exchange thermal energy between the sucked air of the first room and the sucked air of the second room, and to discharge the air of the first room and the air of the second room in which the thermal energy is exchanged, to an air inlet of the first room and an air inlet of the second room. 
     According to an embodiment, to exchange thermal energy between the sucked air of the first room and the sucked air of the second room, the at least one processor may be configured to, by executing the at least one instruction, drive the ventilation fan to mix the sucked air of the first room with the sucked air of the second room, and, to discharge the air of the first room and the air of the second room in which the thermal energy is exchanged, the at least one processor may be configured to, by executing the at least one instruction, discharge the sucked air of the first room and the sucked air of the second room, which are mixed, to the air inlet of the first room and the air inlet of the second room. 
     According to an embodiment, the ventilation fan may be between an air exhaust pipe connecting air outlets of the plurality of rooms and an air supply pipe connecting air inlets of the plurality of rooms. To mix the sucked air of the first room with the sucked air of the second room and to discharge the sucked air of the first room and the sucked air of the second room, which are mixed, the at least one processor may be further configured to, by executing the at least one instruction: open the air inlets and the air outlets of the first room and the second room and close air inlets and air outlets of rooms other than the first room and the second room among the plurality of rooms, and drive the ventilation fan to mix the sucked air of the first room with the sucked air of the second room in the air exhaust pipe and the air supply pipe, and circulate the mixed air between the first room and the second room. 
     According to an embodiment, the air conditioning control device may further include a heat exchange element, wherein, to exchange thermal energy between the sucked air of the first room and the sucked air of the second room, the at least one processor may be configured to, by executing the at least one instruction, cause the sucked air of the first room and the sucked air of the second room to pass through the heat exchange element. To discharge the air of the first room and the air of the second room in which the thermal energy is exchanged, the at least one processor may be configured to, by executing the at least one instruction, discharge the sucked air of the first room in which the thermal energy is exchanged to the air inlet of the first room, and discharge the air of the second room in which the thermal energy is exchanged to the air inlet of the second room. 
     According to an embodiment, the at least one processor may be further configured to, by executing the at least one instruction, perform the exchange of thermal energy and air conditioning together by mixing the sucked air of the second room with outside air prior to the sucked air of the second room being passed through the heat exchange element. 
     According to an embodiment, the at least one processor may be further configured to, by executing the at least on instruction, cause the exchange of thermal energy and cooling and heating to be performed together, by controlling an air conditioning unit in the second room together with the exchange of thermal energy. 
     According to an embodiment, each room of the plurality of rooms may have a corresponding first pipeline control unit and a corresponding second pipeline control unit, each room of the plurality of rooms may have an air outlet connectable to an air exhaust pipe or a heat recovery air exhaust pipe by the corresponding first pipeline control unit, each room of the plurality of rooms may have an air inlet connectable to an air supply pipe or a heat recovery air supply pipe by the corresponding second pipeline control unit, the air exhaust pipe may be connected to the heat recovery air supply pipe and the air supply pipe may be connected to the heat recovery air exhaust pipe, in the heat exchange element, and the at least one processor may be further configured to, by executing the at least one instruction, control the first pipeline control unit and the second pipeline control unit corresponding to each room of the plurality of rooms, in association with driving of the ventilation fan, to exchange thermal energy between the sucked air of the first room and the sucked air of the second room. 
     According to an embodiment, the at least one processor may be further configured to, by executing the at least one instruction, stop driving the ventilation fan as a difference between a temperature of the first room and a temperature of the second room decreases to a preset temperature difference or less. 
     According to an embodiment, the air conditioning control device may further includes a user input unit, wherein the at least one processor may be further configured to, by executing the at least one instruction: receive a user input to set an energy recovery threshold time through the user input unit, and stop driving the ventilation fan as the set energy recovery threshold time has elapsed since start of driving of the ventilation fan. 
     According to an embodiment, the air conditioning control device may further include a user input unit and a display, wherein the at least one processor may be further configured to, by executing the at least one instruction: display, on the display, a room selection menu showing at least one of the sensor value and the use schedule, together with identification information of the plurality of rooms, and receive a user input to select the first room from which thermal energy is to be recovered and the second room to which thermal energy is to be supplied, from among the plurality of rooms, through the user input unit. 
     According to an embodiment, a method may include: (a) determining, among a plurality of rooms, a first room from which thermal energy is to be recovered and a second room to which the thermal energy to be recovered is to be supplied, based on at least one of a sensor value of a sensor in a room among the plurality of rooms, a use schedule of at least one room among the plurality of rooms, and a user input; and (b) driving a ventilation fan to suck air of the first room through an air outlet of the first room, to suck air of the second room through an air outlet of the second room, to exchange thermal energy between the sucked air of the first room and the sucked air of the second room, and to discharge the air of the first room and the air of the second room in which the thermal energy is exchanged to an air inlet of the first room and an air inlet of the second room. 
     According to an embodiment, the driving the ventilation fan to exchange thermal energy between the sucked air of the first room and the sucked air of the second room may include driving the ventilation fan to mix the sucked air of the first room with the sucked air of the second room, and the driving the ventilation fan to discharge the air of the first room and the air of the second room in which the thermal energy is exchanged may include driving the ventilation fan to discharge the sucked air of the first room and the sucked air of the second room, which are mixed, to the air inlet of the first room and the air inlet of the second room. 
     According to an embodiment, the ventilation fan may be between an air exhaust pipe connecting air outlets of the plurality of rooms and an air supply pipe connecting air inlets of the plurality of rooms, and the driving the ventilation fan to mix the sucked air of the first room with the sucked air of the second room and the driving the ventilation fan to discharge the sucked air of the first room and the sucked air of the second room, which are mixed, may include: opening the air inlets and the air outlets of the first room and the second room, closing air inlets and air outlets of rooms other than the first room and the second room among the plurality of rooms, and driving the ventilation fan to mix the sucked air of the first room with the sucked air of the second room in the air exhaust pipe and the air supply pipe, and to circulate the mixed air between the first room and the second room. 
     According to an embodiment, to exchange thermal energy between the sucked air of the first room and the sucked air of the second room, the driving the ventilation fan may include driving the ventilation fan to cause the sucked air of the first room and the sucked air of the second room to pass through a heat exchange element, and, to discharge the air of the first room and the air of the second room in which the thermal energy is exchanged, the driving the ventilation fan may include driving the ventilation fan to discharge the sucked air of the first room in which thermal energy is exchanged to the air inlet of the first room, and to discharge the air of the second room in which thermal energy is exchanged to the air inlet of the second room. 
     According to an embodiment, the driving the ventilation fan to exchange thermal energy between the sucked air of the first room and the sucked air of the second room may include driving the ventilation fan to cause the exchange of thermal energy and air conditioning to be performed together by mixing the sucked air of the second room with outside air prior to the sucked air of the second room being passed through the heat exchange element. 
     According to an embodiment, the method may further include performing thermal energy exchange and cooling and heating together by controlling an air conditioning unit in the second room. 
     According to an embodiment, each room of the plurality of rooms may have a corresponding first pipeline control unit and a corresponding second pipeline control unit, each room of the plurality of room may have an air outlet connectable to an air exhaust pipe or a heat recovery air exhaust pipe by the corresponding first pipeline control unit, each room of the plurality of rooms may have an air inlet connectable to an air supply pipe or a heat recovery air supply pipe by the corresponding second pipeline control unit, the air exhaust pipe may be connected to the heat recovery air supply pipe and the air supply pipe may be connected to the heat recovery air exhaust pipe, in the heat exchange element, and, to exchange thermal energy between the sucked air of the first room and the sucked air of the second room, the method may include controlling the first pipeline control unit and the second pipeline control unit corresponding to each room of the plurality of rooms, in association with driving of the ventilation fan, to exchange thermal energy between the sucked air of the first room and the sucked air of the second room. 
     According to an embodiment, the method may include stopping driving the ventilation fan as a difference between a temperature of the first room and a temperature of the second room decreases to a preset temperature difference or less. 
     According to an embodiment, the method may include receiving a user input to set an energy recovery threshold time; and stopping driving the ventilation fan as the set energy recovery threshold time has elapsed since start of driving of the ventilation fan. 
     According to an embodiment, the method may further include displaying a room selection menu showing at least one of the sensor value or the use schedule, together with identification information of the plurality of rooms; and receiving a user input to select the first room from which thermal energy is to be recovered and the second room to which thermal energy is to be supplied, from among the plurality of rooms, through the room selection menu. 
     According to an embodiment, an apparatus may include at least one memory storing instructions; and at least one processor configured to, by executing the instructions, perform control to: (a) determine, among a plurality of rooms, a first room from which thermal energy is to be recovered and a second room to which the thermal energy to be recovered is to be supplied, based on at least one of a sensor value of a sensor in a room among the plurality of rooms, a use schedule of at least one room among the plurality of rooms, and a user input, (b) suck air from the first room and air from the second room, (c) exchange thermal energy between the air sucked from the first room and the air sucked from the second room, and (d) discharge the air sucked from the first room and the air sucked from the second room, in which the thermal energy has been exchanged, to the first room and the second room. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Aspects, features, and advantages of embodiments of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    illustrates a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room by using an air supply facility and an air exhaust facility, according to an embodiment of the disclosure. 
         FIG.  2    is a device diagram of an air conditioning control device, according to an embodiment of the disclosure. 
         FIG.  3    is a flowchart of a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room by using an air supply facility and an air exhaust facility, according to an embodiment of the disclosure. 
         FIG.  4    is a flowchart of a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room, according to an embodiment of the disclosure. 
         FIG.  5    illustrates an air conditioning control device and a facility in a room, according to an embodiment of the disclosure. 
         FIGS.  6 A through  6 C  illustrate a method, performed by an air conditioning control device, of recovering thermal energy in a room, according to an embodiment of the disclosure. 
         FIG.  7    is a flowchart of a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room, according to an embodiment of the disclosure. 
         FIG.  8    illustrates an air conditioning control device and a facility in a room, according to another embodiment of the disclosure. 
         FIG.  9 A  illustrates a method, performed by an air conditioning control device, of ventilating a room by using a heat exchange element in an outside air circulation mode, according to another embodiment of the disclosure. 
         FIG.  9 B  illustrates a flow of the air in an air conditioning control device in an outside air circulation mode, according to an embodiment of the disclosure. 
         FIG.  10 A  illustrates a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room to another room by using a heat exchange element in a total heat recovery mode, according to another embodiment of the disclosure. 
         FIG.  10 B  illustrates a flow of the air in an air conditioning control device in a total heat recovery mode, according to an embodiment of the disclosure. 
         FIGS.  11 A and  11 B  are flowcharts of a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room by controlling a pipeline control unit, according to another embodiment of the disclosure. 
         FIG.  12    is a flowchart of a method, performed by an air conditioning control device, of reusing waste heat in a room, according to an embodiment of the disclosure. 
         FIG.  13    illustrates a method of reusing heating and cooling heat in a room by using a user device, according to an embodiment of the disclosure. 
         FIG.  14    illustrates a method of reusing heating and cooling heat in a room by using a user device, according to another embodiment of the disclosure. 
         FIG.  15    is a device diagram of an air conditioning control device, according to another embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Throughout the disclosure, the expression “at least one of a, b or c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof. 
     Hereinafter, embodiments of the disclosure will be described in detail with reference to the attached drawings to allow those of ordinary skill in the art to easily carry out the embodiments of the disclosure. However, the disclosure may be implemented in various different forms, and are not limited to the embodiments of the disclosure described herein. To clearly describe the disclosure, parts that are not associated with the description have been omitted from the drawings, and throughout the specification, identical reference numerals refer to identical parts. 
     Although terms used in the disclosure are selected with general terms popularly used at present under the consideration of functions in the disclosure, the terms may vary according to the intention of those of ordinary skill in the art, judicial precedents, or introduction of new technology. Thus, the terms used in the disclosure should be defined not by the simple names of the terms but by the meaning of the terms and the contents throughout the disclosure. 
     In addition, the terms, first, second, etc., may be used to describe various components, but the components should not be limited by these terms. These terms are used to distinguish one component from another component. 
     Moreover, terms used herein are used for only describing a specific exemplary embodiment and may not have an intention to limit the disclosure. Singular expressions include plural forms unless apparently indicated otherwise contextually. Further, throughout the specification, when any portion is “connected” to another portion, it may include not only a case where they are “directly connected”, but also a case where they are “electrically connected” with another element therebetween. When a portion is referred to as “comprises” a component, the portion may not exclude another component but may further include another component unless stated otherwise. 
     The phrase “in some embodiments” or “in one embodiment” in various parts of the present specification all does not necessarily indicate the same embodiment. 
     Various embodiments of the disclosure provide an electronic device and a method of controlling the same, in which waste heat in a room that is not used is moved to a room to be used. 
       FIG.  1    illustrates a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room by using an air supply facility and an air exhaust facility, according to an embodiment of the disclosure. 
     Referring to  FIG.  1   , there are a plurality of rooms in a building and each room may include air inlets  10 _ 1  through  10 _ 5  and air outlets  20 _ 1  through  20 _ 5 . 
     As shown in  FIG.  1   , when there are several separate rooms in a building, each room may be separately cooled and heated. A user may operate a chiller while staying in Room  1 , and as the chiller operates, cold energy may increase in Room  1 . Even when the user leaves Room  1  after terminating the use of Room  1 , cold energy may remain in Room  1 . However, thermal energy may not exchange between rooms, such that cold energy remaining in Room  1  may be wasted. 
     According to an embodiment of the disclosure, an air conditioning control device  1000  may determine, among a plurality of rooms, a first room from which thermal energy is to be recovered and a second room to which the thermal energy to be recovered is to be supplied, based on at least one of a sensor value received from a sensor in the plurality of rooms, a use schedule of the plurality of rooms, or a user input. 
     For example, referring to  FIG.  1   , the air conditioning control device  1000  may determine Room  1  as the first room from which thermal energy is to be recovered, and determine Room  2  as the second room to which the thermal energy to be recovered is to be supplied. 
     The air conditioning control device  1000  according to an embodiment of the disclosure may exchange the thermal energy between the determined first room and second room. 
     For example, the air conditioning control device  1000  may close the air outlets  20 _ 3 ,  20 _ 4 , and  20 _ 5  and the air inlets  10 _ 3 ,  10 _ 4 , and  10 _ 5  of the other rooms than the first room and the second room, open the air outlet  20 _ 1  of the first room to suck the air in the first room by controlling an air outlet regulator  1020 _ 1  provided in the air outlet  20 _ 1  of the first room, and suck the air in the second room to the air outlet  20 _ 2  of the second room by controlling an air outlet regulator  1020 _ 2  provided in the air outlet  20 _ 2  of the second room. 
     In addition, the air conditioning control device  1000  may exchange thermal energy in the sucked air of the first room and thermal energy in the sucked air of the second room. 
     Moreover, the air conditioning control device  1000  may open the air inlet  10 _ 1  of the first room and the air inlet  10 _ 2  of the second room by controlling the air inlet regulator  1010 _ 1  provided in the air inlet  10 _ 1  of the first room and the air inlet regulator  1010 _ 2  provided in the air inlet  10 _ 2  of the second room, thereby discharging the air of the first room and the air of the second room where thermal energy is exchanged to the air inlet  10 _ 1  of the first room and the air inlet  10 _ 2  of the second room. 
     According to an embodiment of the disclosure, the air conditioning control device  1000  may mix the air sucked from the first room with the air sucked from the second room, thus exchanging thermal energy between the two volumes of air. 
     In addition, according to another embodiment of the disclosure, the air conditioning control device  1000  may exchange thermal energy of the air sucked from the first room with thermal energy of the air sucked from the second room, by using a heat exchange element. 
     Thus, the air conditioning control device  1000  may move thermal energy of the first room to the second room. 
     The air outlet regulators  1020 _ 1  to  1020 _ 5  and the air inlet regulators  1010 _ 1  to  1010 _ 5  may include, but are not limited to, a damper or a pipeline regulating means. 
     According to an embodiment of the disclosure, the room may be a space that may be closed, such as a room in the house, or a partially open space that is not closed, such as a living room or a kitchen. 
     In addition, according to an embodiment of the disclosure, thermal energy may be hot energy or cold energy. For example, when the temperature of the air in Room  1  is lower than a reference temperature due to an air conditioner, Room  1  may be determined to include cold energy. In this case, the air conditioning control device  1000  may determine Room  1  as the first room from which cold energy is to be recovered. 
     In addition, when the temperature of the air in Room  1  is higher than the reference temperature due to a hot-air blower or a heater, Room  1  may be determined to include hot energy. In this case, the air conditioning control device  1000  may determine Room  1  as the first room from which hot energy is to be recovered. 
     The reference temperature may be, for example, but is not limited to, 24 degrees Celsius (° C.). The reference temperature may change with a user&#39;s settings, a season, or an outside temperature. Depending on an embodiment of the disclosure, thermal energy remaining in the room may be referred to as waste thermal energy. 
       FIG.  2    is a device diagram of an air conditioning control device, according to an embodiment of the disclosure. 
     Referring to  FIG.  2   , the air conditioning control device  1000  may include a processor  1200 , a memory  1300 , and a ventilation fan  1610 . 
     The ventilation fan  1610  may include a driving motor (not shown) and fan blades. The ventilation fan  1610  may move the ambient air by rotating the fan blades connected to the driving motor (not shown). As indicated above, singular expressions used herein may include plural forms. Accordingly, the ventilation fan  1610  may be implemented as a single fan or a plurality of fans. 
     The memory  1300  may store a program for processing and control by the processor  1200 , and store identification information of a room and identification information of an air inlet regulator (not shown) and an air outlet regulator (not shown) corresponding to the identification of the room. 
     The processor  1200  may determine, among a plurality of rooms, the first room from which thermal energy is to be recovered and the second room to which the thermal energy to be recovered is to be supplied, based on at least one of a sensor value received from a sensor in a room of the plurality of rooms, a use schedule of at least one room of the plurality of rooms, or a user input. Here, “at least one of” indicates that, in various embodiments, that the processor  1200  may determine the first room and the second room based on any of the following: (a) a sensor value received from a sensor in a room of the plurality of rooms, (b) a use schedule of at least one room of the plurality of rooms, (c) a user input, (d) a sensor value received from a sensor in a room of the plurality of rooms and a use schedule of at least one room of the plurality of rooms, (e) a sensor value received from a sensor in a room of the plurality of rooms and a user input, (f) a use schedule of at least one room of the plurality of rooms and a user input, and (g) a sensor value received from a sensor in a room of the plurality of rooms, a use schedule of at least one room of the plurality of rooms, and a user input. 
     The processor  1200  may exchange thermal energy between the air of the first room sucked through the air outlet of the first room and the air of the second room sucked through the air outlet of the second room and discharge the air of the first room and the air of the second room where the thermal energy is exchanged to the air inlet of the first room and the air inlet of the second room, by driving the air outlet regulator (not shown) and the air inlet regulator (not shown). 
     The processor  1200  and the ventilation fan  1610  may be configured as one device, or may be separated from each other and connected to each other in a wired or wireless manner. 
     According to another embodiment of the disclosure, the air conditioning control device  1000  may include a heat exchange element. According to another embodiment of the disclosure, the air conditioning control device  1000  may include a chiller/heater. Thus, the air conditioning control device  1000  may be referred to as a total heat exchanger, an energy recovery ventilator (ERV), an air conditioner, a system air conditioner, an air conditioning unit, etc. 
       FIG.  3    is a flowchart of a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room by using an air supply facility and an air exhaust facility, according to an embodiment of the disclosure. 
     In operation S 310 , the air conditioning control device  1000  may determine a sensor value received from a sensor in a plurality of rooms, a use schedule of a plurality of rooms, and a user input, and determine a first room to which thermal energy is to be recovered and a second room to which the thermal energy to be recovered is to be supplied, among the plurality of rooms. 
     A room may include a temperature sensor. The room may also include at least one of a humidity sensor, a human body detection sensor, or an air quality sensor. 
     The air conditioning control device  1000  according to an embodiment of the disclosure may determine a room the user leaves or a room the user enters among the plurality of rooms, based on a detection value of the human body detection sensor of the room. 
     The human body detection sensor may detect whether the user is present in the room, whether the user enters the room, or whether the user leaves the room. The human body detection sensor may include, but is not limited to, an image sensor, an infrared sensor, an ultrasonic sensor, a lidar sensor, a contact controller, etc. 
     For example, the air conditioning control device  1000  may determine that all users having stayed in Room  1  leave Room  1 , based on the detection value of the human body detection sensor in Room  1 . More specifically, when the air conditioning control device  1000  receives a signal indicating that the user is not present in Room  1  from the infrared sensor in Room  1  or a signal indicating that all lights are turned off from the contact controller, the air conditioning control device  1000  may determine that all users having stayed in Room  1  leave Room  1 . 
     In addition, the air conditioning control device  1000  may determine that the user enters Room  2 , based on the detection value of the human body detection sensor in Room  2 . For example, when the air conditioning control device  1000  receives the signal indicating the user is present in Room  2  from the infrared sensor or a signal indicating that a light is turned on from the contact controller, the air conditioning control device  1000  may determine that the user enters Room  2 . 
     The air conditioning control device  1000  according to an embodiment of the disclosure may also determine a room that is finished being used or a room that is to be used, based on a use schedule. The air conditioning control device  1000  may receive information about a room use schedule from a device of the user. According to an embodiment of the disclosure, the air conditioning control device  1000  may receive a user input to set the room use schedule. The air conditioning control device  1000  may determine the room finished being used as a room from which thermal energy is to be recovered and the room to be used as a room to which thermal energy is to be supplied, based on the room use schedule. 
     The air conditioning control device  1000  according to an embodiment of the disclosure may determine a room requiring thermal energy between a room the user enters and the room to be used. 
     For example, the air conditioning control device  1000  may determine, based on a reference temperature, that Room  2  requires thermal energy, when an inside temperature of Room  2  between the room the user enters and the room to be used is directed in the same direction as an outside temperature, which deviates from the reference temperature. 
     More specifically, the air conditioning control device  1000  may determine that Room  2  requires thermal energy, when a sign of a value obtained by subtracting the reference temperature from the outside temperature is the same as a sign of a value obtained by subtracting the reference temperature from the inside temperature of Room  2 . For example, when the reference temperature is 25 degrees, the outside temperature is 29 degrees, and the inside temperature is 27 degrees, the sign of the value obtained by subtracting the reference temperature from the outside temperature is the same as the sign of the value obtained by subtracting the reference temperature from the inside temperature and the outside temperature is higher than the inside temperature, such that the air conditioning control device  1000  may determine that Room  2  requires cold energy. In another example, when the reference temperature is 25 degrees, the outside temperature is 19 degrees, and the inside temperature of Room  2  is 22 degrees, the sign of the value obtained by subtracting the reference temperature from the outside temperature is the same as the sign of the value obtained by subtracting the reference temperature from the inside temperature and the outside temperature is lower than the inside temperature, such that the air conditioning control device  1000  determines that Room  2  requires hot energy. Thus, the air conditioning control device  1000  may determine Room  2  as the second room that requires thermal energy. 
     Moreover, the air conditioning control device  1000  according to an embodiment of the disclosure may determine the room to which thermal energy is to be supplied, between a room the user leaves and the room finished being used. 
     For example, when the second room requires hot energy, the air conditioning control device  1000  may determine a room having an inside temperature higher than the reference temperature between the room the user leaves and the room finished being used as the room to which thermal energy is to be supplied. In another example, when the second room requires cold energy, the air conditioning control device  1000  may determine a room having an inside temperature lower than the reference temperature between the room the user leaves and the room finished being used as the room to which thermal energy is to be supplied. 
     The reference temperature may change with a user&#39;s settings, a season, or an outside temperature. For example, the reference temperature may be a desired temperature set by the user in the air conditioning control device  1000 . 
     According to an embodiment of the disclosure, the air conditioning control device  1000  may determine the first room from which thermal energy is to be recovered and the second room to which the thermal energy to be recovered is to be supplied, based on an air quality in a room as well as a human body detection sensor or a use schedule. 
     For example, the air conditioning control device  1000  may not recover the thermal energy of the first room when the humidity or the air quality of the first room deviates from a recovery range, even when the first room from which thermal energy is to be recovered and the second room to which thermal energy is to be supplied is determined based on at least one of the temperature, the human body detection sensor, or the use schedule. The recovery range may include, but is not limited to, a humidity less than or equal to 60% and greater than or equal to 30% and a dust concentration less than or equal to 50 μg/m3. Thus, the air conditioning control device  1000  may not recover the thermal energy of the first room when the humidity of the first room is greater than or equal to 60% or the dust concentration is greater than or equal to 50 μg/m3. 
     The air quality sensor may detect a pollution degree of the air in a room. The air quality sensor may include, but is not limited to, at least one of a dust sensor, a CO 2  sensor, a total volatile organic compound (TVOC) sensor, a temperature sensor, or a humidity sensor. The dust sensor may detect the concentration of dust in the air in a room. The CO 2  sensor may detect the concentration of CO 2  in the air in a room. The TVOC sensor may detect the concentration of harmful gases and the concentration of organic compounds in the air in a room. 
     The air conditioning control device  1000  according to an embodiment of the disclosure may determine a plurality of first rooms from which thermal energy is to be recovered and determine a plurality of second rooms to which thermal energy is to be supplied. 
     According to an embodiment of the disclosure, the air conditioning control device  1000  may determine a first room from which thermal energy is to be recovered and a second room to which thermal energy is to be supplied, based on a user input to select the first room and the second room. 
     In operation S 320 , the air conditioning control device  1000  may drive a ventilation fan to suck the air of the first room through the air outlet of the first room, to suck the air of the second room through the air outlet of the second room, to exchange thermal energy between the sucked air of the first room and the sucked air of the second room, and to discharge the air of the first room and the air of the second room where the thermal energy is exchanged to the air inlet of the first room and the air inlet of the second room. 
     The air conditioning control device  1000  according to an embodiment of the disclosure may mix the air of the first room sucked through the air outlet of the first room with the air of the second room sucked through the air outlet of the second room, thus exchanging thermal energy between the air of the first room and the air of the second room. In this case, the air conditioning control device  1000  may discharge the mixed air to the air inlet of the first room and the air inlet of the second room. 
     The air conditioning control device  1000  according to another embodiment of the disclosure may alternate the air of the first room sucked through the air outlet of the first room with the air of the second room sucked through the air outlet of the second room to avoid mixing thereof, by driving the ventilation fan, thus exchanging thermal energy between the air of the first room and the air of the second room. In this case, the air conditioning control device  1000  may discharge the heat-exchanged air of the first room to the air inlet of the first room and discharge the heat-exchanged air of the second room to the air inlet of the second room. 
     As thermal energy is exchanged between the air of the first room and the air of the second room, the air conditioning control device  1000  may determine whether the first room and the second room satisfy a thermal equilibrium condition. For example, the air conditioning control device  1000  may determine that the first room and the second room satisfy the thermal equilibrium condition when the temperature of the first room and the temperature of the second room become equal to each other. In another example, the air conditioning control device  1000  may determine that the first room and the second room satisfy the thermal equilibrium condition when a difference between the temperature of the first room and the temperature of the second room is within a specific temperature difference. 
     As the air conditioning control device  1000  determines that the first room and the second room satisfy the thermal equilibrium condition, the air conditioning control device  1000  may stop driving the ventilation fan and control an air outlet regulator and an air inlet regulator in a room to stop thermal energy exchange between the first room and the second room. 
     According to another embodiment of the disclosure, even when the thermal equilibrium condition is not satisfied, the air conditioning control device  1000  may stop thermal energy exchange as a specific heat exchange time is exceeded from a start time of the thermal energy exchange. 
     For example, the air conditioning control device  1000  may receive a user input to set an energy recovery threshold time through a user input unit (not shown), and stop driving the ventilation fan as the set energy recovery threshold time has elapsed since start of driving of the ventilation fan. 
     According to another embodiment of the disclosure, the air conditioning control device  1000  may identify whether a room to be supplied with thermal energy is finished being used, and stop the thermal energy exchange between rooms. For example, the air conditioning control device  1000  may stop the thermal energy exchange between rooms, when receiving a signal indicating that all users leave the room, from the human body detection sensor. In another example, the air conditioning control device  1000  may stop the thermal energy exchange between the rooms, when receiving a signal indicating that all lights are turned off, from the contact controller. 
       FIG.  4    is a flowchart of a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room by mixing the air of rooms, according to an embodiment of the disclosure. 
     In operation S 410 , the air conditioning control device  1000  may mix the air of the first room sucked through the air outlet of the first room with the air of the second room sucked through the air outlet of the second room, by driving the ventilation fan. 
     In operation S 420 , the air conditioning control device  1000  may discharge the air of the first room and the air of the second room, which are mixed, to the air inlet of the first room and the air inlet of the second room. 
     As the air of the first room and the air of the second room are mixed and then circulated again in the first room and the second room, the thermal energy of the first room may be recovered to the second room. 
       FIG.  5    illustrates an air conditioning control device and a facility in a room, according to an embodiment of the disclosure. 
     Referring to  FIG.  5   , a room may include an air inlet  10  and an air outlet  20 . The air inlet  10  may include an air inlet regulator  1010  that may open or close the air inlet  10 . The air outlet  20  may include an air outlet regulator  1020  that may open or close the air outlet  20 . 
     The air inlet  10  and the air outlet  20  may be provided on a ceiling of a room. Furthermore, the air inlet  10  and the air outlet  20  may be arranged to be farthest from each other. For example, the air inlet  10  and the air outlet  20  may be arranged near vertices facing diagonally in a room. Thus, as the air discharged to the air inlet  10  after heat exchange is not directly sucked in the air outlet  20 , efficient thermal energy exchange may be achieved between rooms. 
     Moreover, there may be an air quality sensor, a human body detection sensor  140 , an inside temperature sensor  151 , and an indoor humidity sensor  153  in a room. The air quality sensor may include a TVOC sensor  131 , a CO 2  sensor  133 , and a dust sensor  135 . An air conditioning unit  2000  may be further provided in the room. 
     The air conditioning control device  1000  may include at least one of the air inlet regulator  1010 , the air outlet regulator  1020 , the human body detection sensor  140 , the inside temperature sensor  151 , the indoor humidity sensor  153 , or the air quality sensor including the TVOC sensor  131 , the CO 2  sensor  133 , and the dust sensor  135 . 
     The air inlet regulator  1010 , the air outlet regulator  1020 , the human body detection sensor  140 , the inside temperature sensor  151 , the indoor humidity sensor  153 , and the air quality sensor including the TVOC sensor  131 , the CO 2  sensor  133 , and the dust sensor  135  may be connected with the air conditioning control device  1000  in a wired manner or in a short-range wireless communication manner. For example, the air inlet regulator  1010 , the air outlet regulator  1020 , and the air conditioning unit  2000  may be controlled by being connected to the air conditioning control device  1000  by wire, and the other sensors may be controlled by being wirelessly connected to the air conditioning control device  1000 . 
       FIGS.  6 A through  6 C  illustrate a method, performed by an air conditioning control device, of recovering thermal energy in a room by mixing the air of rooms, according to an embodiment of the disclosure. 
     Referring to  FIG.  6 A , in a normal control mode, the air conditioning control device  1000  may close the air inlets  10 _ 1  to  10 _ 5  and the air outlets  20 _ 1  to  20 _ 5  or suck the outside air into the room by using the ventilation fan after opening the air inlets  10 _ 1  to  10 _ 5  and the air outlets  20 _ 1  to  20 _ 5 . The normal control mode may mean when the air conditioning control device  1000  does not recover thermal energy in the room. 
     In the normal control mode, when external ventilation is selected by the user, the air conditioning control device  1000  may control air inlet regulators  1010 _ 1  to  1010 _ 5  and outlet regulators  1020 _ 1  to  1020 _ 5  to open the air inlets  10 _ 1  to  10 _ 5  and the air outlets  20 _ 1  to  20 _ 5 , and drive a ventilation fan  1610  when closing a circulation connection unit  1850 . 
     As shown in  FIG.  6 A , the air inlets  10 _ 1  to  10 _ 5  in the room may be connected to an air supply pipe  15  and the air outlets  20 _ 1  to  20 _ 5  in the room may be connected to an air exhaust pipe  25 . As the ventilation fan  1610  is driven, the volumes of air in the room may be sucked through the air outlets  20 _ 1  to  20 _ 5  and discharged to the outside through the air exhaust pipe  25 , and the outside air may be discharged to the room via the air inlets  10 _ 1  to  10 _ 5  through the air supply pipe  15 . 
     In the normal control mode, when external ventilation is not selected by the user, the air conditioning control device  1000  may control air inlet regulators  1010 _ 1  to  1010 _ 5  and outlet regulators  1020 _ 1  to  1020 _ 5  to close the air inlets  10 _ 1  to  10 _ 5  and the air outlets  20 _ 1  to  20 _ 5 . 
     As shown in  FIG.  6 A , users are using Room  1  that may be cooled by an air conditioning unit. Accordingly, cold energy may be accumulated in Room  1 . 
     Referring to  FIG.  6 B , the air conditioning control device  1000  may recover a part of the cold energy remaining in Room  1  to Room  2 . 
     As users in Room  1  leave Room  1 , the air conditioning control device  1000  may determine that the use of Room  1  is finished, based on the human body detection sensor. As the same user or another user enters Room  2 , the air conditioning control device  1000  may determine that the use of Room  2  begins. 
     When determining that the use of Room  2  begins, the air conditioning control device  1000  may determine, based on the temperature of Room  2 , whether Room  2  requires thermal energy, and, when determining that Room  2  requires thermal energy, may determine Room  1  as the first room from which thermal energy is to be recovered and Room  2  as the second room to which thermal energy is to be supplied. 
     When determining to recover cold energy from the first room and supply the cold energy to the second room, the air conditioning control device  1000  may control the air inlet regulators  1010 _ 1  and  1010 _ 2  and the air outlet regulators  1020 _ 1  and  1020 _ 2  of the first room and the second room to open the air inlet regulators  1010 _ 1  and  1010 _ 2  and the air outlet regulators  1020 _ 1  and  1020 _ 2  of the first room and the second room, and control the air inlet regulators  1010 _ 3  to  1010 _ 5  and the air outlet regulators  1020 _ 3  to  1020 _ 5  of the other rooms than the first room and the second room to close the air inlets  10 _ 3  to  10 _ 5  and the air outlets  20 _ 3  to  20 _ 5 . 
     The air conditioning control device  1000  may connect the air supply pipe  15  to the air exhaust pipe  25  by opening the circulation connection unit  1850  connected to the air supply pipe  15  and the air exhaust pipe  25 . The air conditioning control device  1000  may drive the ventilation fan  1610 . 
     As the ventilation fan  1610  is driven, the air of the first room may be sucked through the air outlet  20 _ 1  of the first room and the air of the second room may be sucked through the air outlet  20 _ 2  of the second room, and the sucked volumes of air may be mixed and discharged to the air inlets  10 _ 1  and  10 _ 2  of the first room and the second room through the air exhaust pipe  25 , the circulation connection unit  1850 , and the air supply pipe  15 , thus forming a closed loop connecting the first room to the second room. As the air of the first room and the air of the second room are mixed, cold energy in the air of the first room and thermal energy in the air of the second room are exchanged, such that a part of the cold energy of the first room may be recovered to the second room. 
     Referring to  FIG.  6 C , the air conditioning control device  1000  may stop driving the ventilation fan  1610  when the first room and the second room enter the thermal equilibrium state. 
     The air conditioning control device  1000  may determine, based on the temperature of the first room and the temperature of the second room, whether thermal equilibrium is achieved between the first room and the second room. For example, the air conditioning control device  1000  may determine that thermal equilibrium is achieved between the first room and the second room, when the temperature of the first room and the temperature of the second room become equal to each other. 
     When determining that thermal equilibrium is achieved between the first room and the second room, the air conditioning control device  1000  may stop driving the ventilation fan  1610 . The air conditioning control device  1000  may control the air outlet regulators  1020 _ 1  and  1020 _ 2  and the air inlet regulators  1010 _ 1  and  1010 _ 2  of the first room and the second room to close the air outlets  20 _ 1  and  20 _ 2  and the air inlets  10 _ 1  and  10 _ 2  of the first room and the second room. When a ventilation mode is set, the air conditioning control device  1000  may open the air outlets  20 _ 1  to  20 _ 5  and the air inlets  10 _ 1  to  10 _ 5  of respective rooms and close the ventilation connection unit  1850 , and then drive the ventilation fan  1610  to replace the air in the room with the outside air. 
     According to an embodiment of the disclosure, when driving of the air conditioning unit is set in the second room, as a closed loop connecting the first room to the second room is released by stopping driving the ventilation fan  1610  without driving the air conditioning unit in thermal energy exchange, the air conditioning control device  1000  may control the air conditioning unit positioned in the second room to start cooling of the second room. 
       FIG.  7    is a flowchart of a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room using a heat exchange element, according to an embodiment of the disclosure. 
     In operation S 710 , the air conditioning control device  1000  may exchange thermal energy as causing the air of the first room sucked through the air outlet of the first room and the air of the second room sucked through the air outlet of the second room to pass through the heat exchange element, by driving the ventilation fan. 
     The heat exchange element may exchange thermal energy of the two volumes of air supplied to the heat exchange element. A route through which the air of the first room passes and a route through which the air of the second room passes are different from each other in the heat exchange element, such that thermal energy exchange may be made without mixing the air of the first room with the air of the second room. 
     In operation S 720 , the air conditioning control device  1000  may discharge the heat-exchanged air of the first room to the air inlet of the first room and discharge the heat-exchanged air of the second room to the air inlet of the second room. 
     As thermal energy is exchanged between the air of the first room and the air of the second room, the first room and the second room may reach the thermal equilibrium state. 
       FIG.  8    illustrates an air conditioning control device and a facility in a room, according to another embodiment of the disclosure. 
     Referring to  FIG.  8   , a room shown in  FIG.  8    may further include a pair of a heat recovery air inlet  10   b  and a heat recovery air outlet  20   b  in addition to the device and the facilities shown in  FIG.  5   . Thus, the room may include a first air inlet  10   a , a second air inlet  10   b , a first air outlet  20   a , and a second air outlet  20   b . The air conditioning control device  1000  may close or open the first air inlet  10   a , the second air inlet  10   b , the first air outlet  20   a , and the second air outlet  20   b  by regulating a first air inlet regulator  1010   a , a second air inlet regulator  1010   b , a first air outlet regulator  1020   a , and a second air outlet regulator  1020   b.    
     The first air inlet  10   a  and the second air inlet  10   b  may be arranged to be farthest from the first air outlet  20   a  and the second air outlet  20   b . For example, the first and second air inlets  10   a  and  10   b  and the first and second air outlets  20   a  and  20   b  may be arranged around diagonally facing vertices. Thus, in another example, the first air inlet  10   a , the second air inlet  10   b , the first air outlet  20   a , and the second air outlet  20   b  may be respectively arranged at respective vertices of the room. 
       FIG.  9 A  illustrates a method, performed by an air conditioning control device, of ventilating a room by using a heat exchange element in an outside air circulation mode, according to another embodiment of the disclosure. 
     Referring to  FIG.  9 A , in the outside air circulation mode, the air conditioning control device  1000  may discharge the inside air and supply the outside air to each room. 
     A plurality of rooms may respectively include first air inlets  10 _ 1   a ,  10 _ 2   a ,  10 _ 3   a ,  10 _ 4   a , and  10 _ 5   a , second air inlets  10 _ 1   b ,  10 _ 2   b ,  10 _ 3   b ,  10 _ 4   b , and  10 _ 5   b , first air outlets  20 _ 1   a ,  20 _ 2   a ,  20 _ 3   a ,  20 _ 4   a , and  20 _ 5   a , and second air outlets  20 _ 1   b ,  20 _ 2   b ,  20 _ 3   b ,  20 _ 4   b , and  20 _ 5   b . The first air inlets  10 _ 1   a ,  10 _ 2   a ,  10 _ 3   a ,  10 _ 4   a , and  10 _ 5   a  of the respective rooms may be connected to a first air supply pipe  15   a , and the second air inlets  10 _ 1   b ,  10 _ 2   b ,  10 _ 3   b ,  10 _ 4   b , and  10 _ 5   b  of the respective rooms may be connected to a second air supply pipe  15   b . The first air outlets  20 _ 1   a ,  20 _ 2   a ,  20 _ 3   a ,  20 _ 4   a , and  20 _ 5   a  of the respective rooms may be connected to a first air exhaust pipe  25   a , and the second air outlets  20 _ 1   b ,  20 _ 2   b ,  20 _ 3   b ,  20 _ 4   b , and  20 _ 5   b  of the respective rooms may be connected to a second air exhaust pipe  25   b.    
     According to an embodiment of the disclosure, the second air inlets  10 _ 1   b ,  10 _ 2   b ,  10 _ 3   b ,  10 _ 4   b , and  10 _ 5   b  may be referred to as heat recovery air inlets, and the second air outlets  20 _ 1   b ,  20 _ 2   b ,  20 _ 3   b ,  20 _ 4   b , and  20 _ 5   b  may be referred to as heat recovery air outlets. 
     The second air supply pipe  15   b  may be connected to an outside air exhaust pipe  45  or a heat exchange element  1900  or may be closed, by an outside air exhaust regulating valve  47 . The second air exhaust pipe  25   b  may be connected to an outside air supply pipe  35  or the heat exchange element  1900  or may be closed, by an outside air supply regulating valve  37 . 
     In the outside air circulation mode, the air conditioning control device  1000  may close the second air inlets  10 _ 1   b ,  10 _ 2   b ,  10 _ 3   b ,  10 _ 4   b , and  10 _ 5   b  and the second air outlets  20 _ 1   b ,  20 _ 2   b ,  20 _ 3   b ,  20 _ 4   b , and  20 _ 5   b , which are heat recovery facilities, and open the first air inlets  10 _ 1   a ,  10 _ 2   a ,  10 _ 3   a ,  10 _ 4   a , and  10 _ 5   a  and the first air outlets  20 _ 1   a ,  20 _ 2   a ,  20 _ 3   a ,  20 _ 4   a , and  20 _ 5   a . The air conditioning control device  1000  may control the outside air supply regulating valve  37  to close the second air exhaust pipe  25   b  and connect the outside air supply pipe  35  to the heat exchange element  1900 . The air conditioning control device  1000  may control the outside air supply regulating valve  47  to close the second air supply pipe  15   b  and connect the outside air exhaust pipe  45  to the heat exchange element. The air conditioning control device  1000  may drive a ventilation fan (not shown) in the air conditioning control device  1000 . 
     When the ventilation fan (not shown) is driven, the volumes of air in the respective rooms may be discharged through the outside air exhaust pipe  45  via the first air outlets  20 _ 1   a ,  20 _ 2   a ,  20 _ 3   a ,  20 _ 4   a , and  20 _ 5   a , the first air exhaust pipe  25   a , and the heat exchange element  1900 , and the outside air may be discharged to the first air inlets  10 _ 1   a ,  10 _ 2   a ,  10 _ 3   a ,  10 _ 4   a , and  10 _ 5   a  through the outside air supply pipe  35  via the heat exchange element  1900  and the first air supply pipe  15   a . Thus, in the outside air circulation mode, the air conditioning control device  1000  may discharge the inside air and supply the outside air to each room. The air conditioning control device  1000  may recover a part of thermal energy in a room through the heat exchange element even discharging the inside air. 
       FIG.  9 B  illustrates a flow of the air in an air conditioning control device in an outside air circulation mode, according to an embodiment of the disclosure. 
     Referring to  FIG.  9 B , in the outside air circulation mode, the air conditioning control device  1000  may control the outside air supply regulating valve  37  and the outside air exhaust regulating valve  47  to discharge the inside air and supply the outside air to a room. 
     The air conditioning control device  1000  may include first to fourth pipe connection units  1910  to  1940 . The first pipe connection unit  1910  may be connected to the second pipe connection unit  1920  through the heat exchange element  1900 , and the third pipe connection unit  1930  may be connected to the fourth pipe connection unit  1940  through the heat exchange element  1900 . 
     The first pipe connection unit  1910  may be connected to the first air exhaust pipe  25   a . The second pipe connection unit  1920  may be connected to the second air supply pipe  15   b  or the outside air exhaust pipe  45  by the outside air exhaust regulating valve  47 . The third pipe connection unit  1930  may be connected to the first air supply pipe  15   a , and the fourth pipe connection unit  1940  may be connected to the second air exhaust pipe  25   b  or the outside air supply pipe  35  by the outside air supply regulating valve  37 . 
     The air conditioning control device  1000  may include a first ventilation fan (not shown) and a second ventilation fan (not shown). 
     In the outside air circulation mode, the air conditioning control device  1000  may control the outside air exhaust regulating valve  47  to connect the outside air exhaust pipe  45  to the second pipe connection unit  1920 . Thus, the first air exhaust pipe  25   a  connected to the first pipe connection unit  1910  may be connected to the outside air exhaust pipe  45  connected to the second pipe connection unit  1920  via the heat exchange element  1900 . The air conditioning control device  1000  may also control the outside air supply regulating valve  37  to connect the outside air supply pipe  35  to the fourth pipe connection unit  1940 . Thus, the first air supply pipe  15   a  connected to the third pipe connection unit  1930  may be connected to the outside air supply pipe  35  connected to the fourth pipe connection unit  1940  via the heat exchange element  1900 . 
     When the first ventilation fan (not shown) is driven, the air of the first room, sucked from the first air exhaust pipe  25   a , may be discharged to the outside via the heat exchange element  1900  and the outside air exhaust pipe  45 . When the second ventilation fan (not shown) is driven, the outside air sucked from the outside air supply pipe  35  may be discharged to the first room via the heat exchange element  1900  and the first air supply pipe  15   a.    
     Thus, in the outside air circulation mode, the air in the room may be exchanged with the outside air. 
       FIG.  10 A  illustrates a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room to another room by using a heat exchange element in a total heat recovery mode, according to another embodiment of the disclosure. 
     Referring to  FIG.  10 A , in the total heat recovery mode, the air conditioning control device  1000  may perform heat exchange between the air of the first room from which thermal energy is to be recovered and the air of the second room to which thermal energy is to be supplied, through the heat exchange element  1900 . 
     The air conditioning control device  1000  may determine Room  1  as the first room from which thermal energy is to be recovered, and determine Room  2  as the second room to which the thermal energy to be recovered is to be supplied. 
     In the total heat recovery mode, the air conditioning control device  1000  may close the air outlets  20 _ 3   a  to  20 _ 5   b  and  20 _ 3   b  to  20 _ 5   b  and the air inlets  10 _ 3   a  to  10 _ 5   b  and  10 _ 3   b  to  10 _ 5   b  of the other rooms than the first room and the second room. 
     In the total heat recovery mode, the air conditioning control device  1000  may open the first air outlet  20 _ 1   a  of the first room and the second air inlet  10 _ 1   b  of the first room, close the first air inlet  10 _ 1   a  of the first room and the second air outlet  20 _ 1   b  of the first room, and control the outside air exhaust regulating valve  47  to connect the first air exhaust pipe  25   a  to the second air supply pipe  15   b  through the heat exchange element  1900 . When the air conditioning control device  1000  drives the first ventilation fan (not shown), a close loop may be formed such that the air of the first room is discharged back to the second air inlet  10 _ 1   b  of the first room via the first air outlet  20 _ 1   a  of the first room and the heat exchange element  1900 . 
     The air conditioning control device  1000  may also open the first air inlet  10 _ 2   a  of the second room and the second air outlet  20 _ 2   b  of the second room, close the first air outlet  20 _ 2   a  of the second room and the second air inlet  10 _ 2   b  of the second room, and control the outside air supply regulating valve  37  to connect the second air exhaust pipe  25   b  to the first air supply pipe  15   a  through the heat exchange element  1900 . When the air conditioning control device  1000  drives the second ventilation fan (not shown), a close loop may be formed such that the air of the second room is discharged back to the first air inlet  10 _ 2   a  of the second room via the second air outlet  20 _ 2   b  of the second room and the heat exchange element  1900 . 
     The air of the first room and the air of the second room may not be mixed with each other in the heat exchange element, and thermal energy of the two volumes of air may be merely exchanged. Thus, the thermal energy of the first room may be recovered to the second room without mixing the volumes of air, such that even the poor air quality of the first room may not affect the air of the second room. The air conditioning control device  1000  may perform individual cooling and heating on the second room, together with heat exchange between the first room and the second room. 
     The air conditioning control device  1000  according to another embodiment of the disclosure may perform air conditioning and ventilation at the same time by introducing the outside air, together with heat exchange between rooms. For example, to perform ventilation of the second room in addition to supplying thermal energy of the first room to the second room, the air conditioning control device  1000  may control the outside air supply regulating valve  37  to connect the heat recovery air exhaust pipe  25   b  to the outside air supply pipe  35  as well as to the heat exchange element  1900 . When the air conditioning control device  1000  drives the second ventilation fan (not shown), the air of the second room, sucked from the heat recovery air outlet  20 _ 2   b , may be mixed with the outside air sucked from the outside air supply pipe  35  and discharged to the air inlet  10 _ 2   a  of the second room via the heat exchange element  1900 . Thus, for the second room, ventilation as well as heat recovery from another room may be performed at the same time. 
       FIG.  10 B  illustrates a flow of the air in an air conditioning control device in a total heat recovery mode, according to an embodiment of the disclosure. 
     Referring to  FIG.  10 B , in the total heat recovery mode, the air conditioning control device  1000  may control the outside air supply regulating valve  37  and the outside air exhaust regulating valve  47  to supply thermal energy remaining in the first room to the second room. 
     In the total heat recovery mode, the air conditioning control device  1000  may control the outside air exhaust regulating valve  47  to connect the second air supply pipe  15   b  to the second pipe connection unit  1920 . Thus, the first air exhaust pipe  25   a  connected to the first pipe connection unit  1910  may be connected to the second air supply pipe  15   b  connected to the second pipe connection unit  1920  via the heat exchange element  1900 . The air conditioning control device  1000  may also control the outside air supply regulating valve  37  to connect the second air exhaust pipe  25   b  to the fourth pipe connection unit  1940 . Thus, the first air supply pipe  15   a  connected to the third pipe connection unit  1930  may be connected to the second air exhaust pipe  25   b  connected to the fourth pipe connection unit  1940  via the heat exchange element  1900 . 
     When the first ventilation fan is driven, the air of the first room, sucked through the first air exhaust pipe  25   a , may be discharged back to the first room via the heat exchange element  1900  and the second air supply pipe  15   b . When the second ventilation fan is driven, the air of the second room, sucked through the second air exhaust pipe  25   b , may be discharged back to the second room via the heat exchange element  1900  and the first air supply pipe  15   a . Thus, heat exchange may be made in the heat exchange element without mixing the air of the first room with the air of the second room. 
       FIGS.  11 A and  11 B  are flowcharts of a method, performed by an air conditioning control device, of recovering thermal energy remaining in a room by controlling a pipeline control unit, according to another embodiment of the disclosure. 
     Referring to  FIG.  11 A , the air conditioning control device  1000  may enable exchange of thermal energy without mixing the air of the first room with the air of the second room, even when each room includes a pair of an air outlet and an air inlet. 
     The air conditioning control device  1000  may determine Room  1  as the first room from which thermal energy is to be recovered, and determine Room  2  as the second room to which the thermal energy to be recovered is to be supplied. 
     The plurality of air outlets  20 _ 1  to  20 _ 5  may be connected to the first air exhaust pipe  25   a  or the second air exhaust pipe  25   b  for heat recovery through air exhaust pipeline control units  65 _ 1 ,  65 _ 2 ,  65 _ 3 ,  65 _ 4 , and  65 _ 5 . The plurality of air inlets  10 _ 1  to  10 _ 5  may be connected to the first air supply pipe  15   a  or the second air supply pipe  15   b  for heat recovery through air supply pipeline control units  55 _ 1 ,  55 _ 2 ,  55 _ 3 ,  55 _ 4 , and  55 _ 5 . 
     The air conditioning control device  1000  may be described with reference to a structure of the air conditioning control device  1000  shown in  FIG.  10 B . For example, in the air conditioning control device  1000 , the first air exhaust pipe  25   a  may be connected to the second air supply pipe  15   b  via the heat exchange element  1900 , and the first air supply pipe  15   a  may be connected to the second air exhaust pipe  25   b  via the heat exchange element  1900 . 
     The air conditioning control device  1000  may control the air supply pipeline control units  65 _ 3 ,  65 _ 4 , and  65 _ 5  and the air exhaust pipeline control units  55 _ 3 ,  55 _ 4 , and  55 _ 5  of the other rooms to close the air outlets  20 _ 3  to  20 _ 5  and the air inlets  10 _ 3  to  10 _ 5  of the other rooms. 
     The air conditioning control device  1000  may drive the first ventilation fan, control the air exhaust pipeline control unit  65 _ 1  of the first room to introduce the air of the first room, sucked through the air outlet  20 _ 1  of the first room, to the first air exhaust pipe  25   a , control the air supply pipeline control unit  55 _ 1  of the first room to induce the air of the first room, introduced to the first air exhaust pipe  25   a  and introduced to the second air supply pipe  15   b  via the heat exchange element  1900 , to the air inlet  10 _ 1  of the first room. 
     The air conditioning control device  1000  may also drive the second ventilation fan, control the air exhaust pipeline control unit  65 _ 2  of the second room to introduce the air of the second room, sucked through the air outlet  20 _ 2  of the second room, to the second air exhaust pipe  25   b , control the air supply pipeline control unit  55 _ 2  of the second room to introduce the air of the second room, introduced to the second air exhaust pipe  25   b  and introduced to the first air supply pipe  15   a  via the heat exchange element  1900 , to the air inlet  10 _ 2  of the second room. 
     Thus, heat exchange may occur in the air conditioning control device  1000  without mixing the air of the first room with the air of the second room. 
     Referring to  FIG.  11 B , the air conditioning control device  1000  may recover thermal energy from a plurality of rooms and then may supply the thermal energy to the second room. 
     The air conditioning control device  1000  may determine Room  5  as well as Room  1  as the first room from which thermal energy is to be recovered. 
     The air conditioning control device  1000  may introduce the air of Room  5 , sucked through the air outlet  20 _ 5  of Room  5 , to the first air exhaust pipe  25   a  by controlling the air exhaust pipeline control unit  65 _ 5  in addition to controlling the pipeline control units  55 _ 1 ,  55 _ 2 ,  65 _ 1 , and  65 _ 2  of Room  1  and Room  2  described in  FIG.  11 A . Thus, the air of Room  1  and the air of Room  2  sucked to the first air exhaust pipe  25   a  may be mixed and then may be introduced to the second air supply pipe  15   b  through the heat exchange element  1900 . In the heat exchange element  1900 , heat exchange may be achieved between a mixture of the air of Room  1  and the air of Room  5  and the air of Room  2 . 
     The air conditioning control device  1000  may control the air supply pipeline control unit  55 _ 5  of Room  5  to introduce the mixed air of Room  1  and Room  5  introduced to the second air supply pipe  15   b  to the air inlet  10 _ 5  of the fifth room as well as the air inlet  10 _ 1  of Room  1 . 
     Thus, the air conditioning control device  1000  may recover thermal energy of Room  1  and Room  5  and supply the thermal energy to Room  2 . 
     According to an embodiment of the disclosure, the air conditioning control device  1000  may supply thermal energy of one room to a plurality of rooms or supply thermal energy of a plurality of rooms to the plurality of rooms, by controlling the pipeline control units  55 _ 1  to  55 _ 5  and  65 _ 1  to  65 _ 5 . 
       FIG.  12    is a flowchart of a method, performed by an air conditioning control device, of reusing waste heat in a room, based on a user input, according to an embodiment of the disclosure. 
     In operation S 1210 , the air conditioning control device  1000  may display a room selection menu showing at least one of a sensor value or a use schedule together with identification information of a plurality of rooms. 
     The sensor value may include a temperature and a humidity. The sensor value may include a human body detection sensor value indicating whether a user is present in a room, whether the user enters the room, or whether the user leaves the room. The sensor value may include an air quality sensor value indicating the degree of pollution of the air in the room. 
     The use schedule may include a scheduled use start time, a scheduled use end time, a scheduled use period, etc. 
     The air conditioning control device  1000  may display a room selection menu showing at least one of a sensor value or a use schedule of each room, together with identification information of the plurality of rooms. 
     In operation S 1220 , the air conditioning control device  1000  may receive a user input to select a first room from which thermal energy is to be recovered and a second room to which thermal energy is to be supplied, from among the plurality of rooms, through the room selection menu. 
     In operation S 1230 , the air conditioning control device  1000  may exchange the thermal energy between the first room and the second room. In operation S 1240 , the air conditioning control device  1000  may determine whether the first room and the second room satisfy the thermal equilibrium condition. In operation S 1250 , the air conditioning control device  1000  may stop recovery of thermal energy as the thermal equilibrium condition is satisfied. Operations S 1230  and S 1250  may be described with reference to operation S 320  of  FIG.  3    and  FIG.  4  or  7   . 
       FIG.  13    illustrates a method of displaying a menu for reusing heating and cooling heat in a room by using a user device, according to an embodiment of the disclosure. 
     Referring to  FIG.  13   , a user device  3000  may provide a user menu for reusing heating and cooling heat in a room. 
     The user device  3000  may include, but is not limited to, a mobile device, a tablet personal computer (PC), a desktop PC, a wall pad, etc. The air conditioning control device  1000  may include the user device  3000 . For example, the user device  3000  may be one of user input units of the air conditioning control device  1000 . 
     The user device  3000  may transmit and receive information to and from the air conditioning control device  1000  using short-range wireless communication or through a server. 
     When receiving a user input to select a heating and cooling heat reuse menu, the user device  3000  may display identification information of a room in a house and a current temperature of the room. In this case, the user device  3000  may display a stereoscopic view  1310  or a plan view of a house or a building. 
     According to an embodiment of the disclosure, the air conditioning control device  1000  may display information regarding the quality of the air of the room (a CO 2  concentration, a dust concentration, a harmful gas concentration, etc.). According to an embodiment of the disclosure, the air conditioning control device  1000  may display information regarding the user in the room (whether the user is present in the room, the number of users, etc.). 
     The user device  3000  may receive a user input to select at least one room for thermal energy exchange. For example, when receiving a user input to select Room R 1   1320  and Room R 4   1330  by drag and drop, the user device  3000  may determine Room R 1   1320  as the first room from which thermal energy is to be recovered and determine Room R 4   1330  as the second room to which thermal energy is to be supplied. The user device  3000  may transmit, to the air conditioning control device  1000 , identification information of Room R 1   1320  and Room R 4   1330  and information indicating that Room R 1   1320  is a room from which thermal energy is to be recovered and Room R 4   1330  is a room to which thermal energy is to be supplied. When receiving information about rooms between which thermal energy is to be exchanged from the user device  3000 , the air conditioning control device  1000  may exchange thermal energy between Room R 1   1320  and Room R 4   1330 . 
     In another embodiment of the disclosure, when receiving a user input to select a plurality of rooms, the user device  3000  may determine the plurality of selected rooms as rooms between which thermal energy is to be exchanged. The user device  3000  may transmit, to the air conditioning control device  1000 , identification information of the plurality of rooms between which thermal energy is to be exchanged. When receiving information about rooms between which thermal energy is to be exchanged from the user device  3000 , the air conditioning control device  1000  may control a ventilation fan, an air supply regulator, and an air exhaust regulator to exchange thermal energy between the plurality of rooms. 
       FIG.  14    illustrates a method of reusing heating and cooling heat in a room by using a user device, according to another embodiment of the disclosure. 
     Referring to  FIG.  14   , a room according to an embodiment of the disclosure may be a room for which a use time is preset, such as a hotel room, a classroom, etc. The user device  3000  may provide a room cooling and heating reuse use menu to reuse waste heat in a room, based on a use schedule of the room. 
     When receiving a user input to select the room cooling and heating reuse use menu, the user device  3000  may display identification information of the room, the temperature of the room, information about the quality of the air, a use end time, or a scheduled use start time. 
     The user device  3000  may determine a room from which thermal energy is to be recovered and a room to which thermal energy is to be supplied, based on a use schedule of the room, the temperature of the room, and the quality of the air. For example, the user device  3000  may determine a room having the remaining thermal energy among rooms that are not scheduled to be used for a specific time from the end of the use, as a room from which thermal energy is to be recovered, based on the temperature of the rooms. For example, the user device  3000  may determine that thermal energy remains in the room, when an inside temperature is in the opposite direction to the outside temperature with respect to a reference temperature. More specifically, the air conditioning control device  1000  may determine that the thermal energy remains in the room, when a sign of a value obtained by subtracting the reference temperature from the outside temperature is different from a sign of a value obtained by subtracting the reference temperature from the inside temperature. For example, when the reference temperature is 25 degrees, the outside temperature is 29 degrees, and the indoor temperature of the room is 23 degrees, it may be determined that cold energy remains in the room. 
     In addition, the user device  3000  may determine, as a room to which thermal energy is to be supplied, a room requiring thermal energy among rooms scheduled to be used within a specific time. For example, the user device  3000  may determine the room as the room to which thermal energy is to be supplied, when the inside temperature is in the same direction as the outside air with respect to the reference temperature. For example, the air conditioning control device  1000  may determine the room as the room to which thermal energy is to be supplied, when the sign of the value obtained by subtracting the reference temperature from the outside temperature is equal to the sign of the value obtained by subtracting the reference temperature from the inside temperature. 
     The user device  3000  may display a user interface  1420  (e.g., a “waste heat supply” button) for supplying the remaining thermal energy to another room in correspondence to the identification information of the room in which the thermal energy remains. The user device  3000  may display a user interface  1410  (e.g., a “waste heat recovery” button) for receiving thermal energy from another room in correspondence to the identification information of the room from which thermal energy may be supplied. 
     When receiving a user input to select the waste heat recovery buttons  1410  and  1430  and the waste heat supply button  1420 , the user device  3000  may transmit identification information of selected rooms to the air conditioning control device  1000 . 
     The air conditioning control device  1000  may recover thermal energy remaining in at least one room to at least one another room by exchanging thermal energy of the selected rooms based on the identification information received from the user device  3000 . 
       FIG.  15    is a device diagram of an air conditioning control device, according to another embodiment of the disclosure. 
     Referring to  FIG.  15   , the air conditioning control device  1000  may include a human body detection sensor  1100 , an air quality sensor  1150 , a thermometer  1160 , a hygrometer  1170 , a processor  1200 , a memory  1300 , an output unit  1400 , a communication unit  1500 , a driving unit  1600 , and a power supply unit  1700 . However, all of the components shown in  FIG.  15    are not essential components of the air conditioning control device  1000 . The air conditioning control device  1000  may be implemented with more components than those shown in  FIG.  15    or may be implemented with fewer components than those shown in  FIG.  15   . Each component will be described sequentially. 
     The human body detection sensor  1100  may include a plurality of sensors configured to detect information regarding whether a user is present in a room, whether the user enters the room, and whether the user leaves the room. For example, the human body detection sensor  1100  may include, but is not limited to, an image sensor  1101  (e.g., a stereo camera, a mono camera, a wide angle camera, an around-view camera, a 3D vision sensor, etc.), an infrared sensor  1102 , an ultrasonic sensor  1103 , a lidar sensor  1104 , a contact controller  1105 , etc. Several image sensors  1101  may be arranged in a room according to an implementation example. A function of each sensor may be intuitively construed from a name of the sensor by those of ordinary skill in the art, and thus will not be described in detail. 
     The air quality sensor  1150  may include a CO 2  sensor  1151 , a dust sensor  1152 , and a TVOC sensor  1153 . The CO 2  sensor  1151  may detect the concentration of CO 2  in the air in a room. The dust sensor  1152  may detect the concentration of dust in the air in the room. The TVOC sensor  1153  may detect the concentration of harmful gases and the concentration of organic compounds in the air in the room. 
     The thermometer  1160 , the hygrometer  1170 , the human body detection sensor  1100 , and the air quality sensor  1150  may be arranged in the room to be wirelessly or wiredly connected to the processor  1200 . 
     The processor  1200  may generally control overall operations of the air conditioning control device  1000 . The processor  1200 , by executing programs stored in the memory  1300 , may control the human body detection sensor  1100 , the air quality sensor  1150 , the thermometer  1160 , the hygrometer  1170 , the output unit  1400 , the communication unit  1500 , the driving unit  1600 , and the power supply unit  1700 . 
     According to an embodiment of the disclosure, the processor  1200  may include an artificial intelligence (AI) processor. The AI processor may be manufactured in the form of a dedicated hardware chip for AI or may be manufactured as a part of an existing general-purpose processor (e.g., a central processing unit (CPU) or an application processor) or a graphic processor (e.g., a graphics processing unit (GPU)) and mounted on the air conditioning control device  1000 . 
     The memory  1300  may store a program for processing and control by the processor  1200 , and store identification information of a room and identification information of an air inlet regulator (not shown) and an air outlet regulator (not shown) corresponding to the identification of the room. 
     The memory  1300  may include a storage medium of at least one type of a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., a secure digital (SD) or extreme digital (XD) memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disc, an optical disc, or the like. The air conditioning control device  1000  may operate a web storage or a cloud server that performs a storage function on the Internet. 
     The output unit  1400  may be intended to output an audio signal, a video signal, or a vibration signal, and may include a display  1411 , an audio output unit  1412 , a vibration motor  1413 , and so forth. 
     The display  1411  may display information processed by the air conditioning control device  1000 . For example, the display  1411  may display identification information of the room, the temperature of the room, the humidity of the room, the human body detection sensor value, and the air quality sensor value, and display the use schedule of the room, whether the user is present in the room or the user leaves the room, etc. 
     The display  1411  may display a user interface (UI) or a graphical user interface (GUI), related to thermal energy exchange. 
     Meanwhile, when the display  1411  and a touch pad are constructed as a touch screen in a layer structure, the display  1411  may be used as an input device as well as an output device. The display  1411  may include at least one of a liquid crystal display (LCD), a thin film transistor (TFT) LCD, an organic light-emitting diode (OLED), a flexible display, a three-dimensional (3D) display, or an electrophoretic display. According to implementation types of the air conditioning control device  1000 , the air conditioning control device  1000  may include two or more displays  1411 . 
     The audio output unit  1412  may output audio data received from the communication unit  1500  or stored in the memory  1300 . In addition, the audio output unit  1412  may output an audio signal related to a function performed in the air conditioning control device  1000 . For example, the audio output unit  1412  may output a voice message indicating that thermal energy exchange between rooms is to start or a voice message indicating that rooms enter the thermal equilibrium state and thus heat exchange is to be stopped. The audio output unit  1412  may include a speaker, a buzzer, or the like. 
     The vibration unit  1413  may output a vibration signal. For example, the vibration unit  1413  may output a vibration signal corresponding to output of audio data or video data (e.g., an alert message, etc.). 
     The communication unit  1500  may include at least one antenna for wirelessly communicating with other devices (e.g., various sensors, a server device (not shown), other display devices (not shown), and a plurality of appliances (not shown)). For example, the communication unit  1500  may include, but is not limited to, a short-range wireless communication unit  1511 , a mobile communication unit  1512 , etc. 
     The short-range wireless communication unit  1511  may include a Bluetooth Low Energy (BLE) communication unit, a near field communication (NFC) unit, a wireless local area network (WLAN) (WiFi) communication unit, a ZigBee communication unit, an infrared Data Association (IrDA) communication unit, a WiFi Direct (WFD) communication unit, an ultra wideband (UWB) communication unit, an Ant+ communication unit, a microwave (uWave) communication unit, etc., without being limited thereto. 
     The mobile communicator  1512  may transmit and receive a radio signal to and from at least one of a base station, an external terminal, or a server over a mobile communication network. Herein, the radio signal may include various forms of data corresponding to transmission/reception of a voice call signal, a video communication call signal, or a text/multimedia message. 
     The driving unit  1600  may include components used in driving (operation) of the air conditioning control device  1000  and operations of internal devices of the air conditioning control device  1000 . The driving unit  1600  may include an air inlet regulator (not shown), an air outlet regulator (not shown), and the ventilation fan  1610 . 
     According to an embodiment of the disclosure, the air conditioning control device  1000  may include a user input unit (not shown). The user input unit may be a means through which a user inputs data for controlling the air conditioning control device  1000 . For example, the user input unit may include, but is not limited to, a keypad, a dome switch, a touch pad (a capacitive overlay type, a resistive overlay type, an infrared beam type, a surface acoustic wave type, an integral strain gauge type, a piezoelectric effect type, etc.), a jog wheel, a jog switch, etc. 
     The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Wherein, the term ‘non-transitory storage medium’ simply means that the storage medium is a tangible device and does not include a signal (e.g., an electromagnetic wave), but this term does not differentiate between where data is semi-permanently stored in the storage medium and where the data is temporarily stored in the storage medium. For example, the ‘non-transitory storage medium’ may include a buffer in which data is temporarily stored. 
     According to an embodiment, the method according to various embodiments disclosed herein may be included and provided in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read only memory (CD-ROM)), or be distributed (e.g., downloaded or uploaded) online via an application store (e.g., Samsung Store™), or between two user devices (e.g., smart phones) directly. When distributed online, at least a part of the computer program product (e.g., a downloadable app) may be at least temporarily stored or temporarily generated in the machine-readable storage medium, such as memory of the manufacturer&#39;s server, a server of the application store, or a relay server.