To prevent false detection by a human sensor provided in an outdoor heat-exchanging housing facility and to precisely detect any suspicious person and the like and provide information to indoor users and the like.

An outdoor water heater 1 is connected to an indoor remote controller 3 via a communication line 2. The water heater 1 is provided with a human sensor 7 for sensing people nearby. A human detection signal outputted from the human sensor 7 when the human sensor 7 detects a person is sent from the water heater 1 to the remote controller 3 via the communication line 2. An informing means provided at the remote controller 3 then provides human detection information using a display and voice. At least either the remote controller 3 or the water heater 1 is provided with a variable human detection sensitivity setting part 11 capable of variably setting the human detection sensitivity of the human sensor 7.