Patent Publication Number: US-2012042662-A1

Title: Indoor unit for air conditioner and control method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No.10-2010-0081405 (filed on Aug. 23, 2010), which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     Exemplary embodiments of the present invention relate to an indoor unit for an air conditioner and a control method thereof. 
     BACKGROUND 
     In general, an air conditioner as a cooling/heating system that suctions indoor air to exchange heat with refrigerant and thereafter, discharge heat-exchanged air to a room is an apparatus forming a refrigeration cycle constituted by a compressor, a condenser, an expansion device, and an evaporator. 
     The air conditioner is classified into a separate type air conditioner in which an outdoor unit and an indoor unit are separated and installed and an integral air conditioner in which the outdoor unit and the indoor unit are integrally installed. 
     In recent years, a multi-type air conditioner in which a plurality of indoor units are connected to one outdoor unit and the plurality of indoor units are installed in different indoor spaces have been generally used. 
     The separate type air conditioner includes the outdoor unit installed outdoors and the indoor unit installed in a building. In addition, a heat exchanger can be provided in each of the outdoor unit and the indoor unit. 
     Meanwhile, in the separate type air conditioner, the indoor unit may be buried in a ceiling. The indoor unit may be called a ceiling buried indoor unit. Air of which heat is exchanged in the ceiling buried indoor unit may be discharged downwardly from the ceiling. In addition, the amount of air discharged from the indoor unit is controlled to vary depending on the height of the ceiling. That is, as the ceiling is higher, a discharge amount of air may be controlled to be larger. 
     In general, the height of the ceiling in which the ceiling buried indoor unit is installed may be various depending on the structure or size of the building. 
     While the ceiling buried indoor unit in the related art was installed in an installation space, there was inconvenience that the size of the installation space, e.g., the height of the ceiling should be additionally set. When the height of the ceiling was not set or wrongly set, the amount of air discharged from the indoor unit was inappropriately controlled. 
     Further, an operation of the indoor unit in the related art is not controlled depending on the actual height of the ceiling but controlled depending on a height section divided with a predetermined width. That is, when different ceiling heights are included in the same height section, air of the same amount may be controlled to be discharged. 
     In this case, a person who lives in an indoor space having a relatively low ceiling height among the ceiling heights included in the same height section feels the cold and a person who lives in an indoor space having a relatively high ceiling height feels the heat. 
     Since discharging of the optimal amount of air in which a user could feel comfort was limited, unnecessary power consumption is wasted in order to receive air having a required temperature. 
     Meanwhile, when the indoor unit is installed to be concentrated on any one side of the indoor space, that is, the indoor unit is installed to be closer to the other wall surface than one wall surface, the discharge amount of air is unbalanced with respect to the entirety of the indoor space. 
     SUMMARY 
     The present invention has been made in an effort to provide an indoor unit for an air conditioner in which the discharge of air can be appropriately controlled depending on an installation height of the indoor unit. 
     Further, the present invention has been made in an effort to provide an indoor unit for an air conditioner in which the discharge amount of air can be appropriately controlled depending on a distance between the indoor unit and a wall surface. 
     In order to achieve the above objects, an exemplary embodiment of the present invention provides an indoor unit for an air conditioner buried in a ceiling and including a heat exchanger with respect to an indoor space defined by a bottom surface, the ceiling, and a plurality of wall surface including: a front panel where a suction part suctioning air of the indoor space; a discharge hole placed on at least one side of the suction part and discharging heat-exchanged air from the heat exchanger; an opening member provided movably to selectively open the discharge hole; a distance sensing unit sensing at least one of a distance up to the bottom surface from the front panel or the indoor unit and a distance up to the wall surface from the indoor unit; and a controller controlling the opening degree of the opening member based on a sensing result sensed by the distance sensing unit. 
     Another exemplary embodiment of the present invention provides an indoor unit for an air conditioner buried in a ceiling and including a suction part suctioning air and heat exchanger exchanging heat with the air suctioned in the suction part with respect to an indoor space defined by a bottom surface, the ceiling, and a plurality of wall surface, including: a discharge hole placed on at least one side of the suction part and discharging heat-exchanged air from the heat exchanger; a blowing fan providing driving force to discharge the air through the discharge hole; discharge veins provided on one side of the discharge hole to selectively opening the discharge hole; a height sensing unit sensing an installation height of the indoor unit; and a controller controlling RPM of the blowing fan or opening degrees of the discharge veins based on the installation height of the indoor unit sensed by the height sensing unit. 
     Yet another exemplary embodiment of the present invention provides a control method of an indoor unit for an air conditioner buried in a ceiling and including a heat exchanger for cooling or heating and discharge veins controlling the discharge amount of air passing through the heat exchanger with respect to an indoor space defined by a bottom surface, a ceiling, and a plurality of wall surface, including: sensing an installation height of the indoor unit based on the bottom surface; determining the discharge amount of the air based on the installation height of the indoor unit; and starting the indoor unit. 
     According to the indoor unit for the air conditioner according to the exemplary embodiments, the installation height of the indoor unit can be measured by the distance sensing sensor and the discharge amount of air can be appropriately controlled depending on the measured height. 
     In addition, since the discharge amount of air is controlled to vary linearly depending on the actual measured height, the indoor space can be effectively cooled or heated. 
     Further, the distance between the indoor unit and the wall surface can be measured by the distance sensing sensor and the discharge amount of air can be appropriately controlled depending on the measured distance up to the wall surface. 
     Since inconvenience to set the installation height disappears while installing the ceiling buried indoor unit, installation can be easier. In addition, cooling or heating efficiency of a conditioned space can be prevented from being deteriorated due to incorrect height setting after installation, and as a result, energy loss which may occur can be prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an indoor unit according to a first exemplary embodiment of the present invention. 
         FIG. 2  is a diagram showing a configuration of the indoor unit according to the first exemplary embodiment of the present invention. 
         FIG. 3  is a flowchart of a control method of the indoor unit according to the first exemplary embodiment of the present invention. 
         FIG. 4  is a graph showing variation in flow rate of discharged air depending on the height of the indoor unit in the first exemplary embodiment of the present invention. 
         FIG. 5  is a block diagram showing a configuration of an indoor unit according to a second exemplary embodiment of the present invention. 
         FIG. 6  is a flowchart of a control method of the indoor unit according to the second exemplary embodiment of the present invention. 
         FIG. 7  is a diagram showing the flow rate of discharged air depending on a position where the indoor unit is placed. 
         FIG. 8  is a block diagram showing a configuration of an indoor unit according to a third exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Hereinafter, detailed exemplary embodiments of the present invention will be described with reference to the accompanying drawings. However, the spirit of the present invention is not limited to the proposed exemplary embodiments but another exemplary embodiment may be easily proposed by those skilled in the art who understand the spirit of the present invention within the same spirit of the present invention. 
       FIG. 1  is a perspective view of an indoor unit according to a first exemplary embodiment of the present invention. 
     Referring to  FIG. 1 , the indoor unit  100  according to the first exemplary embodiment of the present invention includes a body  110  buried in a ceiling and including a plurality of components for air conditioning, which are incorporated therein and a front panel  150  provided on the front of the body  110  and exposed from the ceiling to the outside. 
     Specifically, a suction part  120  through which air of an indoor space is suctioned and a discharge hole  155  through which the suctioned air is discharged after the air suctioned through the suction part  120  is heat-exchanged. 
     The suction part  120  is formed at the center of the front panel  150  and the plurality of discharge holes  155  may be provided around the suction part  120 . However, forming positions of the suction part  120  and the discharge hole  155  are not limited thereto. 
     A discharge vein  164  as an “opening member” selectively opening the discharge hole  155  is included in the front panel  150 . The discharge vein  164  may be provided movably at one side of the discharge hole  155 . According to movement of the discharge vein  164 , e.g., a rotation operation, the amount or a discharge direction of air discharged through the discharge hole  155  may be controlled. 
     Although not shown, a heat exchange for cooling or heating the air suctioned into the indoor unit  100  and a blowing fan providing suction force may be provided in the body  110 . 
     A height sensing unit  170  for sensing an installation height of the indoor unit  100  or the front panel  150 , i.e., a distance between the indoor unit  100  or the front panel  150  and the bottom surface of an installation space thereof is provided in the front panel  150 . 
     The height sensing unit  170  is provided on a front surface of the front panel  150  and may be placed downwardly. A distance measuring sensor may be included in the height sensing unit  170 . 
       FIG. 2  is a diagram showing a configuration of the indoor unit according to the first exemplary embodiment of the present invention. 
     Referring to  FIG. 2 , the indoor unit  100  according to the first exemplary embodiment of the present invention includes the height sensing unit  170  sensing the height of the ceiling where the indoor unit  100  is installed and a temperature sensing unit  175  sensing the temperature of the indoor space. The temperature sensing unit  175  may include a temperature sensor. 
     The indoor unit  100  further includes a fan assembly  180  capable of adjusting the discharge amount of air depending on the height sensed by the height sensing unit  170 . The fan assembly  180  includes a fan motor  182  providing driving force and a blowing fan  184  provided to be rotatable by the fan motor  182 . The RPM of the fan motor  182  is controlled to increase or decrease in proportion to the height of the ceiling. 
     The indoor unit  100  further includes a memory unit  190  storing data. In the memory unit  190 , a table associated with the height sensed by the height sensing unit  170  and the RPM of the fan motor  182  may be mapped and stored. 
     The indoor unit  100  further includes a discharge control unit  160  controlling the amount or discharge direction of the air discharged through the discharge hole  155 . The discharge control unit  160  includes the discharge vein selectively opening the discharge hole  155  and a discharge motor  162  providing driving force to the discharge vein  164 . The discharge vein  164  may be provided to be rotatable or movable straightly. In addition, the plurality of discharge veins  164  may be provided to correspond to the discharge holes  155 . 
     In the memory unit  190 , a table associated with the height sensed by the height sensing unit  170  and an opening degree of the discharge control unit  160  may be mapped and stored. In addition, the indoor unit  100  further includes a controller  200  receiving information sensed by the sensing units  170  and  175  and controlling the driving motors  162  and  182 . 
       FIG. 3  is a flowchart of a control method of the indoor unit according to the first exemplary embodiment of the present invention. Referring to  FIG. 3 , the control method of the indoor unit according to the exemplary embodiment of the present invention will be described. 
     Power is applied to the indoor unit  100 . In this case, the power of the indoor unit may be controlled remotely by a remote controller. 
     In addition, the installation height of the indoor unit, i.e., the height of the ceiling may be sensed by the height sensing unit  170  (S 12 ). When a predetermined height is sensed, the fan motor  182  is controlled with RPM corresponding to the sensed height, and as a result, the blowing fan  184  may be rotated. For example, as the sensed height is higher, the RPM of the fan motor  182  may be higher (S 13 ). 
     The control for compensating for a difference between the indoor temperature sensed by the temperature sensing unit  175  and a set (target) temperature is performed. The compensation control may be performed based on the height of the ceiling. 
     Specifically, a predetermined error value may be generated between a surrounding temperature of the temperature sensing unit  175  positioned around the ceiling and a temperature between locations (approximately 1 to 1.5 in from the bottom surface) which residents feel. The compensation control may be appreciated as a control method for compensating the error value to an appropriate level. 
     A case in which the indoor temperature is 30° C. and the set temperature is 25° C. will be described as an example. In this case, the difference between the indoor temperature and the set temperature as a first temperature difference may be recognized as 5° C. When the ceiling height of the indoor space is 3.2 m, an actual temperature difference (a second temperature difference) is just recognized as 5° C. 
     On the contrary, when the ceiling height is 2.7 m, a value acquired by subtracting a compensation constant a from 5° C. may be recognized as the actual temperature difference. In addition, when the ceiling height is 3.7 m, a value acquired by adding the compensation constant a from 5° C. may be recognized as the actual temperature difference. 
     Therefore, as the ceiling height is higher, the actual temperature difference (the second temperature difference) is higher than the sensed value (the first temperature difference) to compensate for the temperature. Herein, the ceiling height (the installation height of the indoor unit), 3.2 may be a predetermined installation height which is a reference for adding or subtracting the compensation constant. 
     That is, when the installation height of the indoor unit is higher than 3.2, the second temperature difference is compensated to be larger than the first temperature difference and when the installation height of the indoor unit is lower than 3.2 m, the second temperature difference may be compensated to be smaller than the first temperature difference. 
     Meanwhile, data associated with the application of the compensation constant and the temperature compensation may be stored in the memory unit  190  in advance (S 14 ). 
     In addition, an opening angle of the discharge vein  164  may be adjusted by controlling the discharge motor  162 , and as a result, the direction or amount of the air discharge through the discharge hole  155  may be controlled (S 15 ). After the set-up is made, the indoor unit  100  may start (S 16 ). 
       FIG. 4  is a graph showing variation in flow rate of discharged air depending on the height of the indoor unit in the first exemplary embodiment of the present invention. 
     Referring to  FIG. 4 , the amount of the air discharged from the indoor unit  100  varies in linear proportion to the height of the ceiling. 
     Specifically, when the ceiling height sensed by the height sensing unit  170  is Ho, the flow rate of the air discharged through the discharge hole  155  may be controlled as Wo. The flow rate of the air discharged through the discharge hole  155  may be controlled by the RPM of the blowing fan  184  or the opening degree of the discharge vein  164 . In addition, as described above, the flow rate corresponding to the height may be stored in the memory unit  190  in advance. 
     In addition as the height of the ceiling increases (HO→H1→H2), the flow rate of the discharged air increases linearly (WO→W1→W2). That is, the flow rate of the discharged air may be appropriately controlled to correspond to the actual height of the ceiling. 
     By this configuration, even though the indoor unit that is installed in one indoor space is moved to and installed in another indoor space having a difference ceiling height, the flow rate may be automatically controlled depending on the sensed information of the height sensing unit  170  without additionally setting the height. 
     Hereinafter, second and third exemplary embodiments of the present invention will be described. Since the exemplary embodiments are different from the first exemplary embodiment in only some configurations, the difference will be primarily described and the same reference numerals as the first exemplary embodiment will refer to the same components as the first exemplary embodiments. 
       FIG. 5  is a block diagram showing a configuration of an indoor unit according to a second exemplary embodiment of the present invention,  FIG. 6  is a flowchart of a control method of the indoor unit according to the second exemplary embodiment of the present invention, and  FIG. 7  is a diagram showing the flow rate of discharged air depending on a position where the indoor unit is placed. 
     Referring to  FIGS. 5 to 7 , the indoor unit  100  according to the second exemplary embodiment of the present invention includes a wall surface sensing unit  172  sensing a distance to a wall surface of an indoor space from the indoor unit  100  or a front panel  150 . The wall surface sensing unit  172  may include a distance sensor. The wall surface sensing unit  172  and the height sensing unit  170  may be called a “distance sensing unit”. 
     The wall surface sensing unit  172  is provided on the front panel  150  and may be placed so that a sensing direction of the wall surface sensing unit  172  face the wall surface. The wall surface sensing unit  172  may be constituted by a plurality of sensors facing a plurality of wall surfaces. 
     However, unlike this, the wall surface sensing unit  172  may be constituted by one sensor and installed to be rotatable. 
     In this case, the wall surface sensing unit  172  senses a distance up to one wall surface and thereafter, rotates while facing one direction and may sense a distance up to the other wall surface while facing the other direction. In this case, the wall surface sensing unit  172  may further include a direction switching unit switching the direction to face the plurality of wall surfaces. 
     The indoor unit  100  includes a discharge control unit  260  including a plurality of discharge veins. The plurality of discharge veins include a first discharge vein  261 , a second discharge vein  262 , a third discharge vein  263 , and a fourth discharge vein  264 . 
     Opening or not or opening degree of the plurality of discharge veins  261 ,  262 ,  263 , and  264  may be controlled independently. In this case, the indoor unit  100  may include one or more discharge motors for independently driving the plurality of discharge veins  261 ,  262 ,  263 , and  264 . 
     Meanwhile, a table associated with the distance values sensed by the height sensing unit  170  or the wall surface sensing unit  172  and the RPM of the fan motor  182  or the opening degree of the discharge control unit  260  may be mapped and stored in the memory unit  190 . In addition, data regarding application of a compensation constant depending on the distance value and temperature compensation may be stored in the memory unit  190  in advance. 
     Referring to  FIG. 6 , the control method of the indoor unit according to the exemplary embodiment of the present invention will be described. 
     When power is applied to the indoor unit  100 , an installation height of the indoor unit may be sensed by the height sensing unit  170  (S 21  and S 22 ). In addition, distances up to the plurality of wall surfaces from the indoor unit  100  may be respectively sensed through the wall surface sensing unit  172 . 
     In order to form appropriate flow rate to correspond to the sensed height, an output (RPM) of the fan motor  182  is controlled and compensation control for a difference between an indoor temperature and a set temperature depending on the height may be performed (S 25 ). 
     In addition, the RPM of the discharge motor or the opening angels of the discharge veins  261 ,  262 ,  263 , and  264  are adjusted to correspond to the sensed distances up to the wall surface to control a discharge direction and discharge flow rate of air (S 26 ). In addition, the indoor unit  100  starts. Herein, the opening degrees of the discharge veins  261 ,  262 ,  263 , and  264  may be controlled to be different from each other (S 27 ). 
     Specifically, in  FIG. 7 , three cases in which the indoor unit  100  is placed at different positions in an indoor space  300 . It is assumed that the indoor space  300  has a substantially square shape. 
     Referring to  FIG. 7 , when the front panel  150  is positioned substantially at the center of the indoor space  300  (position A), that is, when distances up to  4 -direction wall surfaces  311 ,  312 ,  313 , and  314  from the indoor unit  100  are substantially the same as each other, the opening degrees of the first to fourth discharge veins  261 ,  262 ,  263 , and  264  may be substantially the same as each other. In this case, the flow rate of the air discharged from the indoor unit  100  have substantially equal to each other with respect to four directions. 
     Meanwhile, when the front panel  150  is closest to the first wall surface  311  (position B), specifically, when a distance between the front panel  150  and the first wall surface  311  is shortest, a distance between the front panel  150  and the second wall surface  312  is longest, and distances between the front panel  150  and the third and fourth wall surfaces  313  and  314  are middle distances (position B) the opening degree of the second discharge vein  262  is small and the flow rate of the air discharge from the second discharge vein  262  may be thus smallest. 
     On the contrary, the flow rate discharged from the third discharge vein  263  is largest and the flow rates discharged from the first discharge vein  261  and the fourth discharge vein  264  may be larger than the flow rate discharged from the second discharge vein and smaller than the flow rate discharged from the third discharge vein  263 . In this case, the opening degrees of the discharge veins will be controlled to increase in the order of the second discharge vein  262 , the first and fourth discharge veins  261  and  264 , and the third discharge vein  263 . 
     That is, based on the distance value up to each wall surface from the front panel  150 , the opening degree of each of the discharge veins  261 ,  262 ,  263 , and  264  corresponding thereto may be controlled. 
     Meanwhile, when the front panel  150  is positioned close to the second wall surface  312  (position C), that is, when the distance up to the second wall surface  312  from the indoor unit  100  is smallest, the flow rates discharged from the first discharge vein  261  and the third discharge vein  263  may be smallest. 
     On the contrary, the flow rates discharged from the second discharge vein  262  and the fourth discharge vein  264  may be larger than the flow rates discharged from the first discharge vein  261  and the third discharge vein  263 . 
     Therefore, the plurality of discharge veins are placed to face the plurality of wall surfaces and the opening degree of the discharge vein may be controlled to correspond to the distance value up to the wall surface which each discharge vein faces. That is, as the distance value is larger, the opening degree of the corresponding discharge vein may be larger in proportion thereto. 
     According to the control method, since the opening degree of the discharge vein corresponding to each wall surface may be controlled depending on the distances up to the plurality of wall surfaces, the entire indoor space can be evenly cooled or heated. 
       FIG. 8  is a block diagram showing a configuration of an indoor unit according to a third exemplary embodiment of the present invention. 
     Referring to  FIG. 8 , the indoor unit  100  or the front panel  150  according to the exemplary embodiment includes one distance sensing unit  270  sensing the height of the indoor space or the distance up to the wall surface. 
     The distance sensing unit  270  includes a sensing sensor  272  sensing a distance up to the bottom surface or one wall surface of the indoor space or from the front panel  150  and a direction switching unit  274  switching a placement direction of the sensing sensor  272 . The direction switching unit  274  includes a motor or an actuator. 
     The sensing sensor  272  may sense the installation height of the indoor unit while facing one direction. In addition, the sensing sensor  272  is moved by the direction switching motor  274  and thereafter, may sense a distance up to one wall surface among the plurality of wall surfaces while facing the other direction. 
     Of course, the sensing sensor  272  may respectively sense the distances up to the plurality of wall surfaces while the direction is switched. As described above, one sensing sensor  272  can be direction-switched to sense the installation height of the indoor unit and the distances up to the wall surface in sequence. 
     Consequently, according to the exemplary embodiments, since the plurality of sensors do not need to be provided in order to measure the installation height and the distance up to the wall surface, the configuration of the indoor unit becomes compact and a fabrication cost can be saved.