A radiator that cools an indoor space (50a, 50b) by sucking in cold water from a heat source unit, comprising: a heat exchanger; a first piping, wherethrough the cold water flows from the heat source unit side to the heat exchanger side; a second piping, through which water flows from the heat exchanger side to the heat source unit side; a bypass piping, which diverts the cold water from the first piping to the second piping without passing the cold water through the heat exchanger; a flow volume adjusting mechanism, which adjusts the flow volume of the cold water flowing through the heat exchanger, the flow volume adjusting mechanism capable of assuming a first state in which the first piping and the second piping are connected and a flow of cold water from the heat source unit side to the heat exchanger side is permitted, and a second state corresponding to a blocked state in which the cold water flows from the first piping to the second piping via the bypass piping and the flow of the cold water from the heat source unit side to the heat exchanger side is blocked; a heat exchanger temperature detection unit, which is capable of detecting the temperature of the heat exchanger; and a control unit, which performs a first cooling control that controls the flow volume adjusting mechanism so that the temperature of the heat exchanger detected by the heat exchanger temperature detection unit is greater than or equal to the dew point temperature of air inside the indoor space (50a, 50b), wherein in the first cooling control, the control unit is configured to switch the flow volume adjusting mechanism to the second state if the temperature of the heat exchanger that is detected by the heat exchanger temperature detection unit is lower than the dew point temperature of the air inside the indoor space (50a, 50b). a heat exchanger; a first piping, wherethrough the cold water flows from the heat source unit side to the heat exchanger side; a second piping, through which water flows from the heat exchanger side to the heat source unit side; a bypass piping, which diverts the cold water from the first piping to the second piping without passing the cold water through the heat exchanger; a flow volume adjusting mechanism, which adjusts the flow volume of the cold water flowing through the heat exchanger, the flow volume adjusting mechanism capable of assuming a first state in which the first piping and the second piping are connected and a flow of cold water from the heat source unit side to the heat exchanger side is permitted, and a second state corresponding to a blocked state in which the cold water flows from the first piping to the second piping via the bypass piping and the flow of the cold water from the heat source unit side to the heat exchanger side is blocked; a first state in which the first piping and the second piping are connected and a flow of cold water from the heat source unit side to the heat exchanger side is permitted, and a second state corresponding to a blocked state in which the cold water flows from the first piping to the second piping via the bypass piping and the flow of the cold water from the heat source unit side to the heat exchanger side is blocked; a heat exchanger temperature detection unit, which is capable of detecting the temperature of the heat exchanger; and a control unit, which performs a first cooling control that controls the flow volume adjusting mechanism so that the temperature of the heat exchanger detected by the heat exchanger temperature detection unit is greater than or equal to the dew point temperature of air inside the indoor space (50a, 50b), wherein in the first cooling control, the control unit is configured to switch the flow volume adjusting mechanism to the second state if the temperature of the heat exchanger that is detected by the heat exchanger temperature detection unit is lower than the dew point temperature of the air inside the indoor space (50a, 50b).