Method and system for heating auto-setback

Patent metadata

Field	Value
Publication number	US-2020003441-A1
Application number	US-201816019784-A
Country	US
Kind code	A1
Filing date	Jun 27, 2018
Priority date	Jun 27, 2018
Publication date	Jan 2, 2020
Grant date	—

Abstract

A method of operating an HVAC system using a controller includes predicting a first predicted temperature of an enclosed space during an unoccupied time with the HVAC system off. The controller determines if the first predicted temperature is less than a set-point temperature. Responsive to a determination that the first predicted temperature is less than the set-point temperature, the controller predicts a second predicted temperature of the enclosed space if the HVAC system is operated for a first runtime. The controller determines if the second predicted temperature is less than the set-point temperature and, responsive to a determination that the second predicted temperature is not less than the set-point temperature, the controller operates the HVAC system for the first runtime.

First claim

What is claimed is:

1 . A method of operating an HVAC system, the method comprising, by a controller comprising a central processing unit and memory:
predicting a first predicted temperature of an enclosed space during an unoccupied time with the HVAC system off; determining if the first predicted temperature is less than a set-point temperature; responsive to a determination that the first predicted temperature is less than the set-point temperature, predicting a second predicted temperature of the enclosed space if the HVAC system is operated for a first runtime; determining if the second predicted temperature is less than the set-point temperature; and responsive to a determination that the second predicted temperature is not less than the set-point temperature, operating the HVAC system for the first runtime.

2 . The method of claim 1 , further comprising responsive to a determination that the second predicted temperature is less than the set-point temperature, repeating, for an increased runtime, the step of predicting a second predicted temperature and the step of determining if the second predicted temperature is less than the set-point temperature.

3 . The method of claim 2 , further comprising continuing the repeating until the second predicted temperature is less than the set-point temperature.

4 . The method of claim 1 , further comprising, prior to the step of predicting the first predicted temperature, determining if the enclosed space is unoccupied.

5 . The method of claim 4 , further comprising:
responsive to a determination that the enclosed space is unoccupied, setting a heating demand to zero for the unoccupied time; and proceeding to the step of predicting the first predicted temperature.

6 . The method of claim 4 , further comprising, responsive to a determination that the enclosed space is occupied, repeating the step of determining if the enclosed space is unoccupied until the a determination is made that the enclosed space is unoccupied.

7 . The method of claim 4 , wherein the unoccupied time is a parameter set by a user that indicates a period of time the enclosed space is unoccupied.

8 . The method of claim 4 , wherein the step of determining if the enclosed space is unoccupied comprises determining if a motion sensor has detected motion within the enclosed space.

9 . The method of claim 4 , wherein:
the HVAC system includes a heating element; and when the HVAC system operates in a defrost mode, the heating element is not operated to warm air circulated through the enclosed space when the space is unoccupied.

10 . The method of claim 1 , further comprising, responsive to a determination that the first predicted temperature is greater than the set-point temperature, instructing the HVAC system to not operate during the unoccupied time.

11 . The method of claim 1 , wherein, when performing the step of predicting the first predicted temperature, the controller uses data from an external data source.

12 . The method of claim 1 , wherein, when performing the step of predicting the first predicted temperature, the controller uses historical temperature data.

13 . The method of claim 1 , further comprising repeating the step of predicting the first predicted temperature to update the first predicted temperature.

14 . The method of claim 13 , wherein the step of repeating is done in response to updated weather data from an external data source.

15 . The method of claim 1 , wherein:
the HVAC system is capable of providing heat to the enclosed space by at least two of heat pump operation, electric heating element operation, and furnace operation; and the predicting the second predicted temperature of the enclosed space further comprises selecting, based on cost to operate, one or more of heat pump operation, electric heating element operation, and furnace operation to provide heat to the enclosed space.

16 . An HVAC system comprising:
a compressor configured to compress a refrigerant; an evaporator coil coupled to the compressor and configured to receive the refrigerant; a condenser coil coupled between the evaporator coil and the compressor, a controller comprising a central processing unit and memory, the controller configured to perform the following steps:
predict a first predicted temperature of an enclosed space during an unoccupied time with the HVAC system off;
determine if the first predicted temperature is less than a set-point temperature;
responsive to a determination that the first predicted temperature is less than the set-point temperature, predict a second predicted temperature of the enclosed space if the HVAC system is operated for a first runtime;
determine if the second predicted temperature is less than the set-point temperature; and
responsive to a determination that the second predicted temperature is less than the set-point temperature, operate the HVAC system for the first runtime.

17 . The HVAC system of claim 16 , wherein the controller is further configured to perform the following step:
responsive to a determination that the second predicted temperature is less than the set-point temperature, repeat, for an increased runtime, the step of predicting a second predicted temperature and the step of determining if the second predicted temperature is less than the set-point temperature.

18 . The HVAC system of claim 16 , wherein the controller is further configured to perform the following step:
wherein, when performing the step of predicting the first predicted temperature, the controller uses data from an external data source.

19 . The HVAC system of claim 16 , wherein:
the HVAC system is capable of providing heat to the enclosed space by at least two of heat pump operation, electric heating element operation, and furnace operation; and the controller is further configured to predict the second predicted temperature of the enclosed space by selecting, based on cost to operate, one or more of heat pump operation, electric heating element operation, and furnace operation to provide heat to the enclosed space.

20 . A method of operating an HVAC system using a controller, the method comprising:
determining if an enclosed space of the HVAC system is unoccupied; responsive to a determination that the enclosed space is unoccupied, setting a heating demand to zero for an unoccupied time; predicting a first predicted temperature of the enclosed space during the unoccupied time with the HVAC system off; determining if the first predicted temperature is less than a set-point temperature; responsive to a determination that the first predicted temperature is less than the set-point temperature, predicting a second predicted temperature of the enclosed space if the HVAC system is operated for a first runtime; determining if the second predicted temperature is less than the set-point temperature; responsive to a determination that the second predicted temperature is less than the set-point temperature, operating the HVAC system for the first runtime; and responsive to a determination that the second predicted temperature is less than the set-point temperature, repeating, for an increased runtime, the step of predicting the second predicted temperature and the step of determining if the second predicted temperature is less than the set-point temperature.

Assignees

• Lennox Ind Inc

Inventors

• Brahme Rohini
• Olsen Mark

Classifications

• F24D2200/08

  Electric heater · CPC title

• F24F2120/10

  Occupancy · CPC title

• F25B2400/0411

  for expansion valves or capillary tubes · CPC title

• F24F11/86

  by controlling compressors within refrigeration or heat pump circuits · CPC title

• F24F11/56

  Remote control · CPC title