# US 10,371,407 B2 · Air conditioning apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,407 B2 - Document ID: US10371407B2 - Status: Granted - Kind: B2 - Application number: 15/771,653 - Filed: 2016-10-27 - Published: 2018-11-08 - Granted: 2019-08-06 - Earliest claimed: 2015-10-30 - Assignees: Daikin Industries, Ltd. - Applicants: Daikin Industries, Ltd. - Inventors: Takahiro Nakata; Junya Yoneda - Web page: https://patentgrep.com/patent/US10371407B2 ## CPC - F24F 11/74: for controlling air flow rate or air velocity - F24F 11/77: by controlling the speed of ventilators - F24F 11/89: Arrangement or mounting of control or safety devices - F25B 1/00: Compression machines, plants or systems with non-reversible cycle (F25B3/00, F25B5/00, F25B6/00, F25B7/00, F25B9/00 take precedence) - F24F 11/30: for purposes related to the operation of the system, e.g. for safety or monitoring - F24F 2140/10: Pressure - F24F 2140/12: Heat-exchange fluid pressure - F24F 2221/34: Heater, e.g. gas burner, electric air heater - F25B 2500/07: Exceeding a certain pressure value in a refrigeration component or cycle - F25B 2600/027: by controlling pressure - F25B 2700/193: of the compressor - 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 air conditioning apparatus is equipped with an indoor fan, an indoor heat exchanger, and a control unit. The indoor heat exchanger generates conditioned air by exchanging heat between refrigerant and room air. The control unit sets operating modes. The control unit controls the rotational speed of the indoor fan. More specifically, in a case where the operating mode has been switched from one to the other of a normal heating mode and a hot air mode in which the conditioned air higher in temperature than in the normal heating mode is generated, the control unit lowers the rotational speed at a second rate that is slower than a first rate which is a rate of decrease in the rotational speed in a case where the operating mode is set to the normal heating mode. ## Claims ### Claim 1 An air conditioning apparatus comprising: an indoor fan; an indoor heat exchanger that generates conditioned air by exchanging heat between refrigerant and room air; and a controller that sets operating modes and controls a rotational speed of the indoor fan, wherein in a case where the operating mode has been switched from one to the other of a first heating mode and a second heating mode in which the conditioned air higher in temperature than in the first heating mode is generated, the controller lowers the rotational speed at a second rate that is slower than a first rate which is a rate of decrease in the rotational speed in a case where the operating mode is set to the first heating mode. ### Claim 2 (depends on 1) The air conditioning apparatus according to claim 1, wherein in a case where the operating mode has been switched from one to the other of the first heating mode and the second heating mode, the controller lowers the rotational speed at the second rate if a value relating to refrigerant pressure is higher than a preset threshold value and lowers the rotational speed at the first rate if the value is equal to or less than the threshold value. ### Claim 3 (depends on 2) The air conditioning apparatus according to claim 2, further comprising a condenser and a temperature sensor that detects the temperature of the condenser, wherein the controller lowers the rotational speed at the second rate if an output value of the temperature sensor serving as the value is higher than the threshold value. ### Claim 4 (depends on 2) The air conditioning apparatus according to claim 2, further comprising a compressor and a pressure sensor that detects the refrigerant pressure on a discharge side of the compressor, wherein the controller lowers the rotational speed at the second rate if an output value of the pressure sensor serving as the value is higher than the threshold value. ### Claim 5 (depends on 2) The air conditioning apparatus according to claim 2, wherein the controller lowers the rotational speed to a target rotational speed at the second rate overall by alternating between intervals in which it maintains the rotational speed and intervals in which it lowers the rotational speed. ### Claim 6 (depends on 3) The air conditioning apparatus according to claim 3, wherein the controller lowers the rotational speed to a target rotational speed at the second rate overall by alternating between intervals in which it maintains the rotational speed and intervals in which it lowers the rotational speed. ### Claim 7 (depends on 4) The air conditioning apparatus according to claim 4, wherein the controller lowers the rotational speed to a target rotational speed at the second rate overall by alternating between intervals in which it maintains the rotational speed and intervals in which it lowers the rotational speed. ### Claim 8 (depends on 1) The air conditioning apparatus according to claim 1, wherein the controller lowers the rotational speed to a target rotational speed at the second rate overall by alternating between intervals in which it maintains the rotational speed and intervals in which it lowers the rotational speed.