# US 11,898,763 B2 · Air conditioning system with refrigerant leak management

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- Number: US 11,898,763 B2
- Document ID: US11898763B2
- Status: Granted
- Kind: B2
- Application number: 17/262,552
- Filed: 2018-07-25
- Published: 2021-09-23
- Granted: 2024-02-13
- Earliest claimed: 2018-07-25
- Assignees: Daikin Industries, Ltd.
- Applicants: Daikin Industries, Ltd.
- Inventors: Miki Yamada
- Web page: https://patentgrep.com/patent/US11898763B2

## CPC

- F24F 11/36: to leakage of heat-exchange fluid
- F25B 49/005: {of safety devices (F25B49/02 and F25B49/04 take precedence)}
- F24F 11/86: by controlling compressors within refrigeration or heat pump circuits
- F25B 49/02: for compression type machines, plants or systems
- F24F 2110/12: of the outside air
- F24F 2140/00: Control inputs relating to system states
- F24F 2221/54: Heating and cooling, simultaneously or alternatively
- F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02)
- F25B 2500/222: Detecting refrigerant leaks
- F25B 2700/2104: of an indoor room or compartment
- F25B 2700/2106: of fresh outdoor air
- F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02)
- F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS

## Abstract

An air conditioning system includes: a controller that controls an air conditioner; a thermostat that measures a temperature of an air conditioning target space, changes a contact point to an ON state or an OFF state in accordance with a measurement result, and manages input of a control signal to the controller to control operation of a component of the air conditioner; a connection line group that electrically connects the thermostat and the controller; a relay that switches, to either a conductive state or a cut-off state, at least one of a first connection line that controls a compressor of the air conditioner or a second connection line that controls an indoor fan of the air conditioner, among the connection line group; and a leakage detection sensor that detects refrigerant leakage from the air conditioner, and outputs a signal that controls the relay.

## Claims

### Claim 1

An air conditioning system comprising:
a controller that controls an air conditioner;
a thermostat that
measures a temperature of an air conditioning target space,
changes a contact point to an ON state or an OFF state in accordance with a measurement result, and
manages input of a control signal to the controller to control operation of a component of the air conditioner;
a connection line group that electrically connects the thermostat and the controller, wherein the connection line group includes a compressor operation command communication line that controls a compressor of the air conditioner and a fan operation command communication line that controls an indoor fan of the air conditioner;
a relay that switches, to either a conductive state or a cut-off state, at least one of
the compressor operation command communication line and the fan operation command communication line;
a leakage detection sensor that detects refrigerant leakage from the air conditioner, and outputs a signal that controls the relay; and
a heater that is disposed separately from the air conditioner and that heats the air conditioning target space, wherein
the connection line group further includes a heating operation command communication line that controls the heater, and
when the leakage detection sensor detects refrigerant leakage from the air conditioner, the relay switches the heating operation command communication line to either a conductive state or a cut-off state.

### Claim 2 (depends on 1)

The air conditioning system according to claim 1, wherein
the connection line group further includes a reverse valve operation command communication line that controls a four-way switching valve of the air conditioner, and
when the leakage detection sensor detects refrigerant leakage from the air conditioner, the relay switches the reverse valve operation command communication line to either a conductive state or a cut-off state.

### Claim 3 (depends on 1)

The air conditioning system according to claim 1, wherein
the connection line group further includes an alarm command communication line that transmits a signal from the controller to the thermostat to notify that an abnormality has occurred, and
when the leakage detection sensor detects refrigerant leakage from the air conditioner, the relay switches the alarm command communication line to either a conductive state or a cut-off state.

### Claim 4 (depends on 1)

The air conditioning system according to claim 1, wherein
each connection line of the connection line group includes at least one of a communication line or a terminal.

### Claim 5 (depends on 1)

The air conditioning system according to claim 1, wherein
the air conditioner has an indoor unit and an outdoor unit.

### Claim 6

A method of controlling an air conditioning system, the method comprising:
controlling an air conditioner with a controller;
measuring, with a thermostat, a temperature of an air conditioning target space;
changing, with the thermostat, a contact point to an ON state or an OFF state in accordance with a measurement result;
managing, with the thermostat, input of a control signal to the controller that controls operation of a component of the air conditioner;
connecting the thermostat and the controller with a connection line group including a compressor operation command communication line that controls a compressor of the air conditioner and a fan operation command communication line that controls an indoor fan of the air conditioner;
controlling, with a relay, a conductive state or a cut-off state of at least one of the compressor operation command communication line and the fan operation command communication line;
detecting, with a leakage detection sensor, refrigerant leakage from the air conditioner;
outputting, with the leakage detection sensor, a signal that controls the relay; and
heating the air conditioning target space with a heater that is disposed separately from the air conditioner, wherein
the connection line group further includes a heating operation command communication line that controls the heater, and
when the leakage detection sensor detects refrigerant leakage from the air conditioner, the relay switches the heating operation command communication line to either a conductive state or a cut-off state.

### Claim 7 (depends on 6)

The method according to claim 6, wherein
the connection line group further includes a reverse valve operation command communication line that controls a four-way switching valve of the air conditioner, and
when the leakage detection sensor detects refrigerant leakage from the air conditioner, the relay switches the reverse valve operation command communication line to either a conductive state or a cut-off state.

### Claim 8 (depends on 6)

The method according to claim 6, wherein
the connection line group further includes an alarm command communication line that transmits a signal from the controller to the thermostat to notify that an abnormality has occurred, and
when the leakage detection sensor detects refrigerant leakage from the air conditioner, the relay switches the alarm command communication line to either a conductive state or a cut-off state.

### Claim 9 (depends on 6)

The method according to claim 6, wherein
connecting the thermostat and the controller with the connection line group includes connecting at least one of a communication line or a terminal for each connection line of the connection line group.

### Claim 10 (depends on 6)

The method according to claim 6, wherein
controlling the air conditioner includes controlling an indoor unit of the air conditioner and an outdoor unit of the air conditioner.