Humidity control apparatus

A humidity control apparatus including

• a refrigerant circuit configured such that
• a compressor, an expansion mechanism, and two adsorption heat exchangers on each of which an adsorbent is supported are connected together through a pipe,
• a refrigerant circulation direction is reversible, and
• a vapor compression refrigeration cycle is performed, and
• an air passage configured such that an air flow path switches, depending on the refrigerant circulation direction in the refrigerant circuit, so as to
• cause one of room air or outdoor air taken into the air passage to pass through one of the adsorption heat exchangers serving as a moisture-desorption adsorption heat exchanger functioning as a condenser and
• cause the other one of the room air or the outdoor air to pass through the other one of the adsorption heat exchangers serving as a moisture-absorption adsorption heat exchanger functioning as an evaporator,
• in which a humidification operation is performed, in which
• the outdoor air is supplied to an inside of a room through the moisture-desorption adsorption heat exchanger, and
• the room air is discharged to an outside through the moisture-absorption adsorption heat exchanger, the humidity control apparatus comprising:
• a preheat heat exchanger
• connected to the refrigerant circuit and
• in the humidification operation, positioned upstream of the moisture-desorption adsorption heat exchanger in a flow of the outdoor air in the air passage and serving as a condenser to heat the outdoor air;
• and
• a heat-recovery heat exchanger
• connected to the refrigerant circuit and
• in the humidification operation, positioned downstream of the moisture-absorption adsorption heat exchanger in a flow of the room air in the air passage and serving as an evaporator to recover heat from the room air.