Abstract: A method monitors an air-conditioner having a semi-conductor gas sensor, the method including: determining that a refrigerant leakage has occurred on condition that the detection value is equal to or greater than a first threshold when the fan is in operation; starting operation of the fan as a provisional operation if the detection value is equal to or greater than a second threshold when the fan is not in operation; stopping the provisional operation of the fan; determining that a refrigerant leakage has occurred on condition that the detection value is equal to or greater than a third threshold after stopping the provisional operation of the fan; and taking a predetermined action for outputting alarm information and/or limiting supply of refrigerant to the heat exchanger when a refrigerant leakage is determined to have occurred.

Abstract: A method monitors an air-conditioner having a semi-conductor gas sensor, the method including: determining that a refrigerant leakage has occurred on condition that the detection value is equal to or greater than a first threshold when the fan is in operation; starting operation of the fan as a provisional operation if the detection value is equal to or greater than a second threshold when the fan is not in operation; stopping the provisional operation of the fan; determining that a refrigerant leakage has occurred on condition that the detection value is equal to or greater than a third threshold after stopping the provisional operation of the fan; and taking a predetermined action for outputting alarm information and/or limiting supply of refrigerant to the heat exchanger when a refrigerant leakage is determined to have occurred.

Abstract: A hot-water storage type hot-water supply device includes a heat pump unit (1) for heating water, a hot-water storage tank (21) for storing hot water heated by the heat pump unit (1), and a hot-water supplying heat exchanger (22) placed so as to extend roughly entirely in a vertical direction thereof and which receives water from a lower side thereof and discharges hot water from an upper side thereof.

Abstract: A hot-water storage type hot-water supply device includes a heat pump unit (1) for heating water, a hot-water storage tank (21) for storing hot water heated by the heat pump unit (1), and a hot-water supplying heat exchanger (22) placed so as to extend roughly entirely in a vertical direction thereof and which receives water from a lower side thereof and discharges hot water from an upper side thereof.