# US 11,441,816 B2 · Draft inducer motor control system

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- Number: US 11,441,816 B2
- Document ID: US11441816B2
- Status: Granted
- Kind: B2
- Application number: 16/195,620
- Filed: 2018-11-19
- Published: 2020-05-14
- Granted: 2022-09-13
- Earliest claimed: 2018-11-13
- Assignees: Johnson Controls Tyco IP Holdings LLP
- Applicants: Johnson Controls Technology Company
- Inventors: Thomas D. Chase
- Web page: https://patentgrep.com/patent/US11441816B2

## CPC

- F24F 11/30: for purposes related to the operation of the system, e.g. for safety or monitoring
- F24D 5/04: with return of the air or the air-heater
- F24D 19/1084: {for air heating systems}
- F24F 11/77: by controlling the speed of ventilators
- F24H 3/065: {using fluid fuel}
- F24H 9/1881: using fluid fuel
- F24D 2200/04: Gas or oil fired boiler
- F24D 2200/12: Heat pump
- F24F 2140/10: Pressure
- F24F 2221/18: combined with domestic apparatus
- F24F 2221/54: Heating and cooling, simultaneously or alternatively
- 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)
- F24D: DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR (using steam or condensate extracted or exhausted from steam engine plants for heating purposes F01K17/02)
- F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22)
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

Embodiments of the present disclosure are directed to a furnace that includes a blower configured to operate to force a fluid through the furnace, a motor having a rated speed, in which the motor is coupled to and configured to actuate the blower, and a controller configured to receive data indicative of an operating characteristic of the furnace and regulate operation of the motor to be at or below an operational speed limit. The controller is configured to set the operational speed limit based on the data indicative of the operating characteristic of the furnace, such that the operational speed limit is less than or equal to the rated speed of the motor.

## Claims

### Claim 1

A controller for a furnace system, wherein the controller is configured to:
determine an operational speed limit of a motor of the furnace system based on an operating characteristic of the furnace system, wherein the motor is coupled to and configured to operate a blower to direct a working fluid through the furnace system, the operational speed limit is less than or equal to a rated speed of the motor, and the rated speed is indicative of an upper speed threshold at which the motor is capable of being operated;
identify an operating speed for the motor based on additional data indicative of an operating parameter of the furnace system;
determine the operating speed of the motor based on a target rate at which the blower directs the working fluid through the furnace system; and
operate the motor at the operating speed in response to determining that the operating speed is at or below the operational speed limit.

### Claim 2 (depends on 1)

The controller of claim 1, wherein the controller is configured to reference a lookup table having a plurality of operational speed limit values associated with different applications of the motor and to select an application of the different applications from the lookup table based on the operating characteristic to determine the operational speed limit.

### Claim 3 (depends on 2)

The controller of claim 2, wherein the controller is configured to select an operational speed limit value of the plurality of operational speed limit values as the operational speed limit, wherein the operational speed limit value is associated with the application selected from the lookup table.

### Claim 4 (depends on 1)

The controller of claim 1, wherein the controller is configured to suspend operation of the furnace system based on a signal requesting operation of the motor above the operational speed limit.

### Claim 5 (depends on 1)

The controller of claim 1, wherein the furnace system is one of a plurality of furnace systems, wherein a respective operating characteristic of each furnace system of the plurality of furnace systems is different from respective operating characteristics of other furnace systems of the plurality of furnace systems, and wherein the controller is configured to control each furnace system of the plurality of furnace systems.

### Claim 6 (depends on 1)

The controller of claim 1, wherein the controller is configured to determine the operational speed limit via a user input.

### Claim 7 (depends on 1)

The controller of claim 1, wherein the controller is configured to increase the operating speed of the motor to increase a rate at which the blower removes the working fluid from the furnace system, and decrease the operating speed of the motor to decrease the rate at which the blower removes the working fluid from the furnace system.

### Claim 8

A controller for a furnace system, wherein the controller is configured to:
receive data indicative of an operating characteristic of the furnace system;
reference supplemental data correlating a plurality of operational speed limit values of a motor of the furnace system with respective associated operating characteristics;
set an operational speed limit of the motor at an operational speed limit value of the plurality of operational speed limit values based on reference to the supplemental data indicating that the operational speed limit value correlates with the operating characteristic, wherein the motor is configured to operate a blower to direct a fluid through the furnace system, the operational speed limit is less than or equal to a rated speed of the motor, and the rated speed is a maximum speed at which that the motor is capable of being operated;
determine an operating speed for the motor based on additional data indicative of an operating parameter of the furnace system;
determine the operating speed is at or below the operational speed limit; and
operate the motor at the operating speed in response to determining that the operating speed is at or below the operational speed limit.

### Claim 9 (depends on 8)

The controller of claim 8, wherein the controller is configured to suspend operation of the furnace system based on determining the operating speed is above the operational speed limit.

### Claim 10 (depends on 8)

The controller of claim 8, wherein the controller is configured to identify a model of the furnace system incorporating the data indicative of the operating characteristic, wherein the operating characteristic is a fuel input rating of the furnace system, a heat output rating of the furnace system, a combustion air flow rating of the furnace system, an emissions component limit of an air flow directed through the furnace system, or any combination thereof.

### Claim 11 (depends on 8)

The controller of claim 8, wherein the operating parameter comprises a target rate at which the blower removes the fluid from the furnace system, wherein increasing the operating speed of the motor increases a rate at which the blower removes the fluid from the furnace system, and decreasing the operating speed of the motor decreases the rate at which the blower removes the fluid from the furnace system.

### Claim 12 (depends on 8)

The controller of claim 8, wherein the operating parameter comprises a pressure of the fluid in the furnace system.