Air-conditioning system

1. An air-conditioning system comprising:

a refrigerant system including an outdoor unit, an indoor unit, and a ventilator through which refrigerant circulates and implementing a single refrigeration cycle;

a controller connected to the outdoor unit, the indoor unit and the ventilator with a transmission line, and

a unit configured to detect temperature and humidity of outdoor air,

wherein the refrigerant system includes a compressor, an outdoor heat exchanger, a first expansion valve, an indoor heat exchanger, a second expansion valve, and a ventilator cooler,

wherein the indoor unit includes the indoor heat exchanger, and is configured to circulate room air while adjusting a temperature of the room air,

wherein the ventilator includes the ventilator cooler, and is configured to replace room air with outdoor air, and also to cool and dehumidify outdoor air introduced to a room with the ventilator cooler,

wherein the outdoor unit, the indoor unit, and the ventilator are connected with a refrigerant pipe to form a single refrigerant circuit,

wherein the controller is configured to:

individually determine maximum evaporating temperature setting values and minimum evaporating temperature setting values in both of the indoor heat exchanger and the ventilator cooler in accordance with outdoor air temperature and humidity, and

control evaporating temperatures in the indoor heat exchanger and the ventilator cooler so as to be not more than the maximum evaporating temperature setting values and not less than the minimum evaporating temperature setting values.

2. The air-conditioning system of claim 1 ,

wherein evaporating temperatures in the indoor heat exchanger and the ventilator cooler are controlled based on a temperature difference ΔT obtained by subtracting a set room air target temperature from a detected room air temperature.

3. The air-conditioning system of claim 1 ,

wherein the maximum evaporating temperature setting values and the minimum evaporating temperature setting values each include two types of setting values of a Hi level evaporating temperature at which an evaporating temperature is high and a Lo level evaporating temperature at which an evaporating temperature is low, and the Hi level evaporating temperature and the Lo level evaporating temperature are changed based on the outdoor air temperature and humidity.

4. The air-conditioning system of claim 3 ,

wherein, while setting to the Hi level evaporating temperature is being implemented, when the temperature difference ΔT exceeds a first specified value which is a positive value, or when an absolute humidity difference ΔX between detected room air absolute humidity and set room air target absolute humidity exceeds a second specified value which is a positive value, the maximum evaporating temperature setting values and the minimum evaporating temperature setting values in the indoor heat exchanger are changed to the Lo level evaporating temperature.

5. The air-conditioning system of claim 3 ,

wherein, while setting to the Lo level evaporating temperature is being implemented, when the temperature difference ΔT is less than a third specified value which is a negative value, and when an absolute humidity difference ΔX between detected room air absolute humidity and set room air target absolute humidity is less than a fourth specified value which is a negative value, the maximum evaporating temperature setting values and the minimum evaporating temperature setting values in the indoor heat exchanger are changed to the Hi level evaporating temperature.

6. The air-conditioning system of claim 1 ,

wherein the maximum evaporating temperature setting values and the minimum evaporating temperature setting values are setting values different between the indoor heat exchanger and the ventilator cooler.

7. The air-conditioning system of claim 1 ,

wherein the outdoor air temperature and humidity are divided into four zones with respect to a certain value T0 of a dry-bulb temperature and a certain value X0 of absolute humidity serving as threshold values on a psychrometric chart.

8. The air-conditioning system of claim 7 ,

wherein, among the four zones, in a zone in which at least the outdoor air temperature and humidity are not more than the value T0 of the dry-bulb temperature and not more than the value X0 of the absolute humidity, the maximum evaporating temperature setting values and the minimum evaporating temperature setting values are each set to a Hi level evaporating temperature at which an evaporating temperature is high.

9. The air-conditioning system of claim 7 ,

wherein, among the four zones, in a zone in which at least the outdoor air temperature and humidity are not less than the value T0 of the dry-bulb temperature and not less than the value X0 of the absolute humidity, the maximum evaporating temperature setting values and the minimum evaporating temperature setting values are each set to a Lo level evaporating temperature at which an evaporating temperature is low.

10. The air-conditioning system of claim 7 ,

wherein the value T0 of the dry-bulb temperature and the value X0 of the absolute humidity are changed based on a set room air target temperature.

11. The air-conditioning system of claim 7 ,

wherein the value T0 of the dry-bulb temperature and the value X0 of the absolute humidity are changed based on air volume of the ventilator.

12. The air-conditioning system of claim 1 ,

wherein the indoor heat exchanger and the ventilator cooler are connected in parallel with respect to the compressor in the single refrigerant circuit implementing the single refrigeration cycle.