# US 2017/0284718 A1 · Air-conditioning apparatus

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- Number: US 2017/0284718 A1
- Document ID: US20170284718A1
- Status: Published application
- Kind: A1
- Application number: 15/508,147
- Filed: 2015-09-02
- Published: 2017-10-05
- Earliest claimed: 2014-11-18
- Assignees: Mitsubishi Electric Corporation
- Applicants: Mitsubishi Electric Corporation
- Inventors: Yasuhiro SUZUKI; Takao KOMAI; Akira MAEDA; Mitsuru KAWASHIMA
- Web page: https://patentgrep.com/patent/US20170284718A1

## CPC

- F24F 11/89: Arrangement or mounting of control or safety devices
- F24F 11/30: for purposes related to the operation of the system, e.g. for safety or monitoring
- F24F 11/70: Control systems characterised by their outputs; Constructional details thereof
- F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02)
- F25B 45/00: Arrangements for charging or discharging refrigerant
- F25B 49/005: {of safety devices (F25B49/02 and F25B49/04 take precedence)}
- F25B 49/02: for compression type machines, plants or systems
- F24F 11/32: Responding to malfunctions or emergencies
- F24F 11/36: to leakage of heat-exchange fluid
- F24F 2110/50: Air quality properties
- F25B 2313/0293: related to the indoor fan, e.g. controlling speed
- F25B 2400/12: Inflammable refrigerants
- F25B 2400/121: using R1234
- F25B 2500/222: Detecting refrigerant leaks
- Y02B 30/70: Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
- 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
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

An indoor unit includes an air-sending fan, an air inlet through which air of an indoor space is sucked in, and an air outlet located above the air inlet and through which the air sucked in through the air inlet is blown out to the indoor space. A control unit activates the air-sending fan when leakage of the refrigerant is detected. When M [kg] represents an amount of charge of the refrigerant in a refrigeration cycle, LFL [kg/m3] represents a lower flammable limit of the refrigerant, A [m2] represents a floor area of the indoor space, and Ho [m] represents a height of the air outlet above a floor surface of the indoor space, the amount of charge M, the lower flammable limit LFL, the floor area A, and the height Ho satisfy a relationship of M<LFL×A×Ho.

## Claims

### Claim 1

An air-conditioning apparatus comprising:
a refrigeration cycle through which refrigerant is circulated; and
an indoor unit accommodating at least an indoor heat exchanger of the refrigeration cycle, the indoor unit being disposed in an indoor space
the refrigerant being a flammable refrigerant with a density greater than a density of air under atmospheric pressure,
the indoor unit including an air-sending fan, an air inlet through which air of the indoor space is sucked in, and an air outlet through which the air sucked in through the air inlet is blown out to the indoor space,
the air-conditioning apparatus being configured to dilute leaked refrigerant by operation of the air-sending fan,
when M [kg] represents an amount of charge of the refrigerant in the refrigeration cycle, LFL [kg/m3] represents a lower flammable limit of the refrigerant, A [m2] represents a floor area of the indoor space, and Ho [m] represents a height of the air outlet above a floor surface of the indoor space, the amount of charge M, the lower flammable limit LFL, the floor area A, and the height Ho satisfying a relationship of M<LFL×A×Ho.

### Claim 2

An air-conditioning apparatus comprising:
a refrigeration cycle through which refrigerant is circulated; and
an indoor unit accommodating at least an indoor heat exchanger of the refrigeration cycle, the indoor unit being disposed in an indoor space; and
the refrigerant being a flammable refrigerant with a density greater than a density of air under atmospheric pressure,
the indoor unit including an air-sending fan, an air inlet through which air of the indoor space is sucked in, an air outlet through which the air sucked in through the air inlet is blown out to the indoor space, and a vertical air deflector vane located at the air outlet,
the air-conditioning apparatus being configured to dilute leaked refrigerant by operation of the air-sending fan and to blow out the air upward through the air outlet by the vertical air deflector vane,
when M [kg] represents an amount of charge of the refrigerant in the refrigeration cycle, LFL [kg/m3] represents a lower flammable limit of the refrigerant, A [m2] represents a floor area of the indoor space, Ho [m] represents a height of the air outlet above a floor surface of the indoor space, and Hc [m] represents a height of a ceiling surface above the floor surface of the indoor space, the amount of charge M, the lower flammable limit LFL, the floor area A, the height Ho, and the height Hc satisfying a relationship of LFL×A×Ho≦M<LFL×A×Hc.

### Claim 3

(canceled)

### Claim 4 (depends on 1)

The air-conditioning apparatus of claim 1, wherein the floor area is a floor area specified by specifications of the air-conditioning apparatus or the indoor unit.

### Claim 5 (depends on 1)

The air-conditioning apparatus of claim 1, further comprising a control unit configured to control the indoor unit, wherein the control unit is configured to activate the air-sending fan when leakage of the refrigerant is detected.

### Claim 6 (depends on 5)

The air-conditioning apparatus of claim 5, wherein
the indoor unit includes a refrigerant detection unit, and
the control unit is configured to activate the air-sending fan by a time when concentration of the refrigerant detected by the refrigerant detection unit reaches ¼ of the lower flammable limit.

### Claim 7 (depends on 1)

The air-conditioning apparatus of claim 1, wherein
the indoor unit includes a refrigerant detection unit,
the indoor heat exchanger is connected to an extension pipe via a coupling, and
the refrigerant detection unit is provided in a housing of the indoor unit and below the indoor heat exchanger and the coupling.

### Claim 8 (depends on 1)

The air-conditioning apparatus of claim 1, wherein a direction in which the air is blown out through the air outlet is a horizontal direction.

### Claim 9 (depends on 2)

The air-conditioning apparatus of claim 2, wherein the floor area is a floor area specified by specifications of the air-conditioning apparatus or the indoor unit.

### Claim 10 (depends on 2)

The air-conditioning apparatus of claim 2, further comprising a control unit configured to control the indoor unit, wherein the control unit is configured to activate the air-sending fan and set the vertical air deflector vane to an upward orientation when leakage of the refrigerant is detected.

### Claim 11

A refrigerant amount setting method of an air-conditioning apparatus,
the air-conditioning apparatus including
a refrigeration cycle through which refrigerant is circulated, and
an indoor unit accommodating at least an indoor heat exchanger of the refrigeration cycle, the indoor unit being disposed in an indoor space,
the refrigerant being a flammable refrigerant with a density greater than a density of air under atmospheric pressure,
the indoor unit including an air-sending fan, an air inlet through which air of the indoor space is sucked in, and an air outlet through which the air sucked in through the air inlet is blown out to the indoor space,
the air-conditioning apparatus being configured to dilute leaked refrigerant by operation of the air-sending fan,
the refrigerant amount setting method of the air-conditioning apparatus comprising setting an amount of the refrigerant of the air-conditioning apparatus,
the setting including,
when M [kg] represents an amount of charge of the refrigerant in the refrigeration cycle, LFL [kg/m3] represents a lower flammable limit of the refrigerant, A [m2] represents a floor area of the indoor space, and Ho [m] represents a height of the air outlet above a floor surface of the indoor space, setting the amount of charge M so that the amount of charge M, the lower flammable limit LFL, the floor area A, and the height Ho satisfy a relationship of M<LFL×A×Ho.

### Claim 12 (depends on 11)

The refrigerant amount setting method of an air-conditioning apparatus of claim 11, wherein the floor area is a floor area specified by specifications of the air-conditioning apparatus or the indoor unit.

### Claim 13

A refrigerant amount setting method of an air-conditioning apparatus,
the air-conditioning apparatus including
a refrigeration cycle through which refrigerant is circulated, and
an indoor unit accommodating at least an indoor heat exchanger of the refrigeration cycle, the indoor unit being disposed in an indoor space,
the refrigerant being a flammable refrigerant with a density greater than a density of air under atmospheric pressure,
the indoor unit including an air-sending fan, an air inlet through which air of the indoor space is sucked in, an air outlet through which the air sucked in through the air inlet is blown out to the indoor space, and a vertical air deflector vane located at the air outlet,
the air-conditioning apparatus being configured to dilute leaked refrigerant by operation of the air-sending fan and to blow out the air upward through the air outlet by the vertical air deflector vane,
the refrigerant amount setting method of the air-conditioning apparatus comprising setting an amount of the refrigerant of the air-conditioning apparatus,
the setting including,
when M [kg] represents an amount of charge of the refrigerant in the refrigeration cycle, LFL [kg/m3] represents a lower flammable limit of the refrigerant, A [m2] represents a floor area of the indoor space, Ho [m] represents a height of the air outlet above a floor surface of the indoor space, and Hc [m] represents a height of a ceiling surface above the floor surface of the indoor space, setting the amount of charge M so that the amount of charge M, the lower flammable limit LFL, the floor area A, the height Ho, and the height Hc satisfy a relationship of LFL×A×Ho≦M<LFL×A×Hc.

### Claim 14 (depends on 13)

The refrigerant amount setting method of an air-conditioning apparatus of claim 13, wherein the floor area is a floor area specified by specifications of the air-conditioning apparatus or the indoor unit.