ENVIRONMENTAL CONTROL APPARATUS AND ENVIRONMENTAL CONTROL METHOD

PROBLEM TO BE SOLVED: To provide an environmental control apparatus and an environmental control method that can control the temperature and humidity in a predetermined space with high precision.SOLUTION: A cooling device 10 provided in a thermohygrostat 1 executes a series of refrigerating cycles, and is a refrigerator including a compressor 12, a condenser 13, a first expansion valve 14, an evaporator 15, a second expansion valve 16, and a refrigerant piping 18 connecting those apparatuses in a loop. The second expansion valve 16 is positioned upstream of the evaporator 15. The outlet of the evaporator 15 is narrowed by adjusting the opening extent of the second expansion valve 16. When the opening extent of the second expansion valve 16 is reduced while a refrigerant is being injected into the evaporator 15, refrigerant gas staying in the evaporator 15 is compressed and the temperature of a part or the whole of the top surface of the evaporator 15 rises. Further, part or the whole of water sticking on the top surface of the evaporator 15 is evaporated or sublimated.