Air-conditioning apparatus

Abstract

An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a flow switching device, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger are connected by pipes and through which refrigerant flows, and a control device controlling an operation of the refrigerant circuit to perform switching between a heating operation and a defrosting operation. The control device includes a determination unit that determines, based on operation information regarding the refrigerant circuit, during the heating operation, whether to change a requirement for starting the defrosting operation, a changing unit that changes the requirement for starting the defrosting operation in accordance with a result of determination by the determination unit, and a switching unit that, when the requirement for starting the defrosting operation is satisfied, causes the flow switching device to perform switching to start the defrosting operation.

1 . An air-conditioning apparatus comprising:
 a refrigerant circuit in which a compressor, a flow switching device, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger are connected by pipes, and through which refrigerant flows; and   a processor configured to control an operation of the refrigerant circuit to perform switching between a heating operation and a defrosting operation,   wherein the processor is configured to:
 determine, based on operation information regarding the refrigerant circuit, during the heating operation, whether or not to change a requirement for starting the defrosting operation; 
 change the requirement for starting the defrosting operation in accordance with a result of determination of whether or not to change a requirement for starting the defrosting operation and a result of determination of whether or not it is presumed that the heating operation is required; and 
 cause, when the requirement for starting the defrosting operation is satisfied, the flow switching device to perform switching to start the defrosting operation. 
   
     
     
         2 . The air-conditioning apparatus of  claim 1 , further comprising:
 a human body detection device configured to detect presence or absence of a human body,   wherein the processor is configured to change the requirement for starting the defrosting operation in accordance with the result of determination of whether or not to change the requirement for stating the defrosting operation and a result of detection by the human body detection device.   
     
     
         3 . The air-conditioning apparatus of  claim 1 , further comprising:
 a remote controller configured to transmit a stop signal to stop the operation of the refrigerant circuit,   wherein the processor is configured to allow starting the defrosting operation upon receiving the stop signal from the remote controller, and   wherein when starting the defrosting operation is allowed, the processor causes the flow switching device to perform switching to start the defrosting operation.   
     
     
         4 . The air-conditioning apparatus of  claim 1 ,
 wherein the processor is configured to allow starting the defrosting operation upon receiving a thermo-off signal indicating a thermo-off state in which the heating operation is temporarily stopped since an actual indoor temperature is higher than a set temperature, and   wherein when starting the defrosting operation is allowed, the processor causes the flow switching device to perform switching to start the defrosting operation.   
     
     
         5 . The air-conditioning apparatus of  claim 1 , further comprising:
 an outdoor heat-exchanger temperature detection device configured to detect a temperature of the outdoor heat exchanger,   wherein the requirement for starting the defrosting operation is that the temperature detected by the outdoor heat-exchanger temperature detection device is at or below an outdoor heat-exchanger temperature threshold, and   wherein the processor is configured to change, during the heating operation, the outdoor heat-exchanger temperature threshold to an outdoor heat-exchanger temperature relaxed threshold higher than the outdoor heat-exchanger temperature threshold in accordance with the operation information regarding the refrigerant circuit.   
     
     
         6 . The air-conditioning apparatus of  claim 1 , further comprising:
 an outdoor temperature detection device configured to detect an outdoor temperature,   wherein the operation information is the temperature detected by the outdoor temperature detection device,   wherein the processor is configured to determine whether or not the temperature detected by the outdoor temperature detection device is at or below an outdoor temperature threshold, and   wherein when it is determined that the temperature detected by the outdoor temperature detection device is at or below the outdoor temperature threshold, the processor changes the requirement for starting the defrosting operation.   
     
     
         7 . The air-conditioning apparatus of  claim 1 , further comprising:
 a frequency detection device configured to detect an operation frequency of the compressor,   wherein the operation information is the operation frequency detected by the frequency detection device,   wherein the processor is configured to determine whether or not the operation frequency detected by the frequency detection device is at or above a frequency threshold, and   wherein when the processor determines that the operation frequency detected by the frequency detection device is at or above the frequency threshold, the processor changes the requirement for starting the defrosting operation.   
     
     
         8 . The air-conditioning apparatus of  claim 1 , further comprising:
 a time measurement device configured to measure an operation time period of the defrosting operation,   wherein the operation information is the operation time period measured by the time measurement device,   wherein the processor is configure to determine whether or not an operation time period of a preceding defrosting operation measured by the time measurement device is at or above a time threshold, and   wherein when it is determined that the operation time period of the preceding defrosting operation measured by the time measurement device is at or above the time threshold, the processor changes the requirement for starting the defrosting operation.