# US 10,310,475 B2 · System and method of operating a variable speed HVAC system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,475 B2 - Document ID: US10310475B2 - Status: Granted - Kind: B2 - Application number: 15/288,868 - Filed: 2016-10-07 - Published: 2017-04-13 - Granted: 2019-06-04 - Earliest claimed: 2015-10-09 - Assignees: Carrier Corporation - Applicants: Carrier Corporation - Inventors: Nick Conklin - Web page: https://patentgrep.com/patent/US10310475B2 ## CPC - F24F 11/86: by controlling compressors within refrigeration or heat pump circuits - F24F 11/70: Control systems characterised by their outputs; Constructional details thereof - F24F 11/83: by controlling the supply of heat-exchange fluids to heat-exchangers - F25B 49/02: for compression type machines, plants or systems - G05B 19/0428: {Safety, monitoring (G05B19/0423 takes precedence)} - F24F 11/64: using pre-stored data - F25B 2600/0253: with variable speed - F25B 2700/2104: of an indoor room or compartment - 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 - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A system and method of operating an HVAC system, the HVAC system including a HVAC unit including a variable speed HVAC component in communication with a unit controller, an interface device in communication with the unit controller, and a single-speed system controller in communication with the interface device, the method including operating the interface device to receive a first conditioning signal from the system controller, operating the interface device to determine a temperature differential when the first conditioning signal is received, operating the interface device to transmit the temperature differential to the unit controller, operating the unit controller to transmit a speed signal based on the temperature differential, operating the interface device to receive a second conditioning signal, and operating the interface device to update the at least one set point estimate when second conditioning signal is received. ## Claims ### Claim 1 A method for operating an HVAC system, the HVAC system including a HVAC unit including a variable speed HVAC component in communication with a unit controller, an interface device in communication with the unit controller, and a single-speed system controller in communication with the interface device, the method comprising: (a) operating the interface device to receive a first conditioning signal from the single-speed system controller, wherein the single-speed system controller is configured to receive a user selected set point temperature from a user and to transmit the first conditioning signal from the single-speed system controller to the interface device, wherein the first conditioning signal that is transmitted from the single-speed system controller to the interface device does not include the user selected set point temperature; (b) operating the interface device to determine a temperature differential; (c) operating the interface device to transmit the temperature differential to the unit controller; (d) operating the unit controller to transmit a speed signal to the variable speed HVAC component based on the temperature differential; and (e) operating the interface device to receive a second conditioning signal from the single-speed system controller. ### Claim 2 (depends on 1) The method of claim 1, wherein the first conditioning signal comprises at least one of a heating on signal and a cooling on signal, and the second conditioning signal comprises at least one of a heating off signal and a cooling off signal, wherein the first conditioning signal and the second conditioning signal do not include the user selected set point temperature. ### Claim 3 (depends on 2) The method of claim 2, wherein the temperature differential comprises the difference between a current space temperature and at least one set point estimate. ### Claim 4 (depends on 3) The method of claim 3, wherein the at least one set point estimate comprises a heating set point estimate or a cooling set point estimate. ### Claim 5 (depends on 4) The method of claim 4, wherein step (d) comprises: (i) if the first conditioning signal is a heating on signal, operating the unit controller to transmit a speed signal indicative of a maximum heating operational speed if the current space temperature is greater than the heating set point estimate; (ii) if the first conditioning signal is a heating on signal, operating the unit controller to transmit a speed signal based on the temperature differential if the current space temperature is less than or equal to the heating set point estimate; (iii) if the first conditioning signal is a cooling on signal, operating the unit controller to transmit a speed signal indicative of a maximum cooling operational speed if the current space temperature is less than the cooling set point estimate; and (iv) if the first conditioning signal is a cooling on signal, operating the unit controller to transmit a speed signal based on the temperature differential if the current space temperature is greater than or equal to the cooling set point estimate. ### Claim 6 (depends on 5) The method of claim 5, wherein step (e) further comprises: (i) operating the interface device to update the heating set point estimate to equal the current space temperature if the second conditioning signal is a heating off signal; and (ii) operating the interface device to update the cooling set point estimate to equal the current space temperature if the second conditioning signal is a cooling off signal. ### Claim 7 An HVAC system comprising: a single speed-system controller; an interface device in communication with the single speed-system controller, the interface device comprising: a processor; a memory in communication with the processor; and a temperature sensor in communication with the processor, the temperature sensor configured to measure a current space temperature; wherein the processor is configured to (a) receive a first conditioning signal from the single-speed system controller, wherein the single-speed system controller is configured to receive a user selected set point temperature from a user and to transmit the first conditioning signal from the single-speed system controller to the interface device, wherein the first conditioning signal that is transmitted from the single-speed system controller to the interface device does not include the user selected set point temperature; (b) determine a temperature differential when the first conditioning signal is received; (c) transmit the temperature differential; and (d) receive a second conditioning signal from the single-speed system controller. ### Claim 8 (depends on 7) The HVAC system of claim 7, wherein the temperature differential comprises the difference between the current space temperature and at least one set point estimate. ### Claim 9 (depends on 8) The HVAC system of claim 8, wherein the at least one set point estimate comprises a heating set point estimate or a cooling set point estimate. ### Claim 10 (depends on 9) The HVAC system of claim 9, wherein the processor is further configured to: (i) update the heating set point estimate to equal the current space temperature if the second conditioning signal is a cooling off signal; and (ii) update the cooling set point estimate to equal the current space temperature if the second conditioning signal is a cooling off signal. ### Claim 11 (depends on 9) The HVAC system of claim 9, further comprising an HVAC unit in communication with the interface device, the HVAC unit comprising: a unit controller; and a variable speed component in communication with the unit controller; wherein the unit controller is configured to: (a) receive the first conditioning signal and the temperature differential from the interface device; (b) operate the variable speed component at a maximum heating operational speed if the current space temperature is greater than the heating set point estimate, and if the first conditioning signal is a heating on signal; (c) operate the variable speed component at an operational speed based on the temperature differential if the current space temperature is less than or equal to the heating set point estimate, and if the first conditioning signal is a heating on signal; (d) operate the variable speed component at a maximum cooling operational speed if the current space temperature is less than the cooling set point estimate, and if the first conditioning signal is a cooling on signal; and (e) operate the variable speed component at an operational speed based on the temperature differential if the current space temperature is greater than or equal to the cooling set point estimate, and if the first conditioning signal is a cooling on signal. ### Claim 12 (depends on 11) The HVAC system of claim 11, wherein the variable speed HVAC component comprises at least one of a compressor and an indoor fan. ### Claim 13 (depends on 7) The HVAC system on claim 7, wherein the single-speed system controller is further configured to transmit the second conditioning signal. ### Claim 14 (depends on 13) The HVAC system of claim 13, wherein the single-speed system controller is in either a wired or wireless communication with the interface device. ### Claim 15 (depends on 13) The HVAC system of claim 13, wherein the single-speed system controller comprises a thermostat. ### Claim 16 An interface device comprising: a processor; a memory in communication with the processor; and a temperature sensor in communication with the processor, the temperature sensor configured to measure a current space temperature; wherein the processor is configured to operate a program stored in memory, the program configured to: (a) receive a first conditioning signal from a single-speed system controller, wherein the single-speed system controller is configured to receive a user selected set point temperature from a user and to transmit the first conditioning signal from the single-speed system controller to the interface device, wherein the first conditioning signal that is transmitted from the single-speed system controller to the interface device does not include the user selected set point temperature; (b) determine a temperature differential when the first conditioning signal is received; (c) transmit the temperature differential; and (d) receive a second conditioning signal from the single-speed system controller. ### Claim 17 (depends on 16) The interface device of claim 16, wherein the temperature differential comprises a difference between the current space temperature and at least one set point estimate stored in the memory. ### Claim 18 (depends on 17) The interface device of claim 17, wherein the at least one set point estimate comprises a heating set point estimate or a cooling set point estimate. ### Claim 19 (depends on 18) The interface device of claim 18, wherein the program is further configured to: (i) update the heating set point estimate to equal the current space temperature if the second conditioning signal is a heating off signal; and (ii) update the cooling set point estimate to equal the current space temperature if the second conditioning signal is a cooling off signal.