Ventilation apparatus, air conditioning system, and ventilation system

Abstract

A ventilation apparatus includes a processor; a compressor; a first heat exchanger; a first air flow path configured to supply air from outdoors to an indoor space after passing through the first heat exchanger; a second heat exchanger; a second air flow path configured to exhaust air from the indoor space to the outdoors after passing through the second heat exchanger; and a refrigerant circuit through which a refrigerant flows, the refrigerant circuit being connected to the compressor, and the first and second heat exchangers. The processor detects whether a predetermined reference indicating a possibility of frosting in the second heat exchanger is satisfied while the second heat exchanger is functioning as an evaporator, and controls a temperature of the refrigerant flowing through the second heat exchanger such that the second heat exchanger will have a temperature at which frosting does not occur, when the predetermined reference is satisfied.

What is claimed is: 
     
         1 . A ventilation apparatus comprising:
 a processor;   a compressor;   a first heat exchanger configured to function as a condenser or an evaporator;   a first air flow path configured to supply air taken in from outdoors to an indoor space after passing through the first heat exchanger;   a second heat exchanger configured to function as a condenser or an evaporator;   a second air flow path configured to exhaust air taken in from the indoor space to the outdoors after passing through the second heat exchanger;   a refrigerant circuit through which a refrigerant flows, the refrigerant circuit being connected to the compressor, the first heat exchanger, and the second heat exchanger by a refrigerant pipe; and   a memory storing one or more programs, which when executed, cause the processor to:   detect whether a predetermined reference indicating a possibility of frosting in the second heat exchanger is satisfied while the second heat exchanger is functioning as an evaporator, and to control a temperature of the refrigerant flowing through the second heat exchanger such that the second heat exchanger will have a temperature at which frosting does not occur in the second heat exchanger, when the processor detects that the predetermined reference is satisfied.   
     
     
         2 . The ventilation apparatus according to  claim 1 , wherein the processor detects whether the predetermined reference is satisfied while the second heat exchanger is functioning as an evaporator, and outputs a signal for controlling an air conditioner provided in the indoor space to control the temperature of the refrigerant flowing through the second heat exchanger, when the processor detects that the predetermined reference is satisfied. 
     
     
         3 . The ventilation apparatus according to  claim 2 , wherein the processor outputs a signal for increasing a temperature currently set for the air conditioner, with respect to the air conditioner provided in the indoor space, when the processor detects that the predetermined reference is satisfied. 
     
     
         4 . The ventilation apparatus according to  claim 2 , further comprising:
 a second ventilation device configured to adjust an air volume flowing to the second heat exchanger upon flowing through the second air flow path, wherein   the processor drives the second ventilation device when an air temperature in the indoor space becomes higher than a second threshold, after outputting the signal for controlling the air conditioner.   
     
     
         5 . The ventilation apparatus according to  claim 1 , wherein
 the refrigerant circuit includes a bypass pipe configured to pass the refrigerant to the second heat exchanger without involving the first heat exchanger while the second heat exchanger is functioning as an evaporator, wherein   the processor implements control to cause the refrigerant that has been compressed at the compressor to flow to the second heat exchanger via the bypass pipe, when the predetermined reference is satisfied.   
     
     
         6 . The ventilation apparatus according to  claim 1 , further comprising:
 a third air flow path configured to take in air from a space that is different from a space from which the second air flow path takes in air in the indoor space, and to pass the taken in air to the second heat exchanger; and   a first guide configured to switch between whether or not to guide air to the second heat exchanger through the third air flow path, wherein   the processor controls the first guide to guide air to the second heat exchanger through the third air flow path when the predetermined reference is satisfied.   
     
     
         7 . The ventilation apparatus according to  claim 1 , further comprising:
 a first ventilation device configured to adjust an air volume flowing to the first heat exchanger upon flowing through the first air flow path; and   a second ventilation device configured to adjust an air volume flowing to the second heat exchanger upon flowing through the second air flow path, wherein   the processor controls the first ventilation device to increase the air volume flowing to the first heat exchanger and controls the second ventilation device to increase the air volume flowing to the second heat exchanger compared to before the predetermined reference is satisfied, upon determining that the predetermined reference is satisfied when a signal indicating to perform a defrosting operation is received from an air conditioner provided in the indoor space, while the second heat exchanger is functioning as an evaporator.   
     
     
         8 . The ventilation apparatus according to  claim 1 , further comprising:
 a bypass flow path configured to guide air that has undergone heat exchange by the first heat exchanger to the second heat exchanger; and   a second guide configured to switch between whether or not to guide air to the second heat exchanger through the bypass flow path, wherein   the processor controls the second guide to guide air to the second heat exchanger through the bypass flow path when the predetermined reference is satisfied.   
     
     
         9 . The ventilation apparatus according to  claim 1 , further comprising:
 a second ventilation device configured to adjust an air volume flowing to the second heat exchanger upon flowing through the second air flow path, wherein   the processor implements control to stop the compressor and to control the second ventilation device to cause air that has passed through the second air flow path to flow to the second heat exchanger, when the predetermined reference is satisfied.   
     
     
         10 . The ventilation apparatus according to  claim 1 , wherein the processor controls the first heat exchanger such that a temperature of air that has passed through the first heat exchanger becomes lower than a temperature set in an air conditioner provided in the indoor space, when the predetermined reference is satisfied. 
     
     
         11 . The ventilation apparatus according to  claim 1 , further comprising:
 a third valve part provided downstream from the second heat exchanger in a flow of the refrigerant in the refrigerant circuit when the second heat exchanger functions as an evaporator, wherein   the processor implements control to throttle the third valve part compared to before the predetermined reference is satisfied, when the predetermined reference is satisfied, when the second heat exchanger functions as an evaporator.   
     
     
         12 . The ventilation apparatus according to  claim 11 , further comprising:
 a third heat exchanger configured to function as a condenser or an evaporator; and   a fourth air flow path configured to exhaust, to the outdoors, air obtained by performing heat exchange between air of the outdoors and the refrigerant flowing through the third heat exchanger, wherein   the refrigerant circuit is connected to the third heat exchanger by the refrigerant pipe in addition to the compressor, the first heat exchanger, and the second heat exchanger.   
     
     
         13 . An air conditioning system comprising:
 a processor;   a ventilation apparatus including:
 a compressor configured to operate when a heat recovery ventilation operation is performed; 
 a first heat exchanger configured to function as a condenser or an evaporator; 
 a first air flow path configured to supply air taken in from outdoors to an indoor space after passing through the first heat exchanger; 
 a second heat exchanger configured to function as a condenser or an evaporator; 
 a second air flow path configured to exhaust air taken in from the indoor space to the outdoors after passing through the second heat exchanger; and 
 a refrigerant circuit through which a refrigerant flows, the refrigerant circuit being connected to the compressor, the first heat exchanger, and the second heat exchanger by a refrigerant pipe, 
   an air conditioner including:
 a third heat exchanger configured to function as a condenser or an evaporator; and 
 an air conditioning indoor device configured to exhaust, to the indoor space, air obtained by performing heat exchange between air of the indoor space and the refrigerant flowing through the third heat exchanger, and 
   a memory storing one or more programs, which when executed, cause the processor to:   detect whether a predetermined reference indicating a possibility of frosting in the second heat exchanger is satisfied, and when the predetermined reference is determined to be satisfied, the processor controls a temperature of the refrigerant flowing through the second heat exchanger such that the second heat exchanger will have a temperature at which frosting does not occur in the second heat exchanger, or controls an operation to defrost the second heat exchanger after frosting has occurred in the second heat exchanger, based on power consumption of the ventilation apparatus the air conditioner required for controlling the temperature of the refrigerant flowing through the second heat exchanger such that the second heat exchanger will have a temperature at which frosting does not occur in the second heat exchanger and power consumption of the ventilation apparatus the air conditioner required for defrosting the second heat exchanger after frosting has occurred in the second heat exchanger.   
     
     
         14 . A ventilation system comprising:
 a processor;   a refrigerant circuit through which a refrigerant flows, the refrigerant circuit being connected to a compressor, a first heat exchanger, and a second heat exchanger by a refrigerant pipe;   an air supply fan configured to supply air from outdoors to indoors through the first heat exchanger;   an exhaust fan configured to exhaust air from the indoors to the outdoors through the second heat exchanger; and   a memory storing one or more programs, which when executed, cause the processor to:   start the compressor when the second heat exchanger functions as an evaporator, and when the processor determines that a low pressure of the refrigerant circuit or an evaporation temperature of the second heat exchanger or a temperature of the indoors or a temperature of the outdoors has dropped below a first threshold with respect to the low pressure of the refrigerant circuit or the evaporation temperature of the second heat exchanger or the temperature of the indoors or the temperature of the outdoors, the processor performs first control to raise the low pressure of the refrigerant circuit.   
     
     
         15 . The ventilation system according to  claim 14 , wherein
 the refrigerant circuit includes:
 a bypass pipe configured to connect a discharge pipe of the compressor and the second heat exchanger or a liquid pipe connected to the second heat exchanger; and 
 a valve provided in the bypass pipe, wherein 
   the processor opens the valve in the first control.   
     
     
         16 . The ventilation system according to  claim 14 , wherein the processor causes the second heat exchanger to take in air having a temperature higher than a second threshold with respect to an intake air temperature, in the first control.