Selecting a fallback temperature sensor for no occupancy

1. A method for controlling a heating, ventilation, and air conditioning (HVAC) system for a building, the method comprising:

prompting, at a controller of the HVAC system, a user to select a temperature sensor from a plurality of temperature sensors in the building to be a fallback temperature sensor, wherein the plurality of temperature sensors in the building are associated with a plurality of spaces within the building;

receiving, at the controller, user input indicating the fallback temperature sensor after prompting the user;

determining, by the controller, that the plurality of spaces within the building are unoccupied;

determining, by the controller, a temperature sensed by the fallback temperature sensor based on communication between the controller and the fallback temperature sensor;

causing, by the controller, the HVAC system to turn on or off based on the temperature at the fallback temperature sensor in response to determining that the plurality of spaces within the building are unoccupied;

at a time after determining that the plurality of spaces within the building are unoccupied, determining, by the controller, that at least one space of the plurality of spaces within the building is occupied;

determining a temperature at a first temperature sensor of the plurality of temperature sensors based on communication between the controller and the first temperature sensor, wherein the first temperature sensor is associated with the at least one space; and

causing the HVAC system to turn on or off based on the temperature at the first temperature sensor in response to determining that the at least one space within the building is occupied.

2. The method of claim 1 ,

wherein the fallback temperature sensor is a selected fallback temperature sensor, and

wherein prompting the user comprises presenting an indication of a recommended fallback temperature sensor to the user.

3. The method of claim 2 , further comprising:

determining that the controller has not received the user input; and

selecting the recommended fallback temperature sensor as the selected fallback temperature sensor in response to determining that the controller has not received the user input.

4. The method of claim 2 ,

wherein a thermostat of the HVAC system comprises the controller and an integrated temperature sensor, and

wherein presenting the indication of the recommended fallback temperature sensor comprises presenting an indication of the integrated temperature sensor to the user as the recommended fallback temperature sensor.

5. The method of claim 2 , further comprising receiving the user input indicating that the user has not selected the recommended fallback temperature sensor as the selected fallback temperature sensor,

wherein prompting the user further comprises:

presenting indications of other temperature sensors of the plurality of temperature sensors in response to determining that the user has not selected the recommended fallback temperature sensor as the selected fallback temperature sensor; and

prompting the user to select the fallback temperature sensor from the other temperature sensors.

6. The method of claim 1 , further comprising:

determining that a new temperature sensor has been added to the plurality of temperature sensors;

prompting the user whether the new temperature sensor should be the fallback temperature sensor in response to determining that the new temperature sensor has been added to the plurality of temperature sensors.

7. The method of claim 1 ,

wherein each temperature sensor of the plurality of temperature sensors comprises a combined temperature and occupancy sensor,

wherein determining that the plurality of spaces within the building are unoccupied comprises determining no occupancy in the plurality of spaces is based on communication between the controller and the plurality of temperature sensors.

8. The method of claim 1 ,

wherein receiving the user input indicating the fallback temperature sensor comprises receiving the user input indicating two or more fallback temperature sensors from the plurality of temperature sensors,

wherein determining the temperature at the fallback temperature sensor comprises determining temperatures at the two or more fallback temperature sensors based on communication between the controller and the two or more fallback temperature sensors, and

wherein controlling the HVAC system comprises controlling the HVAC system based on an average value of the temperatures at the two or more fallback temperature sensors in response to detecting no occupancy in the plurality of spaces.

9. The method of claim 1 , wherein the fallback temperature sensor is different from the first temperature sensor.

10. A controller for a heating, ventilation, and air conditioning (HVAC) system in a building, the controller comprising:

a user interface configured to:

prompt a user to select a temperature sensor from a plurality of temperature sensors in the building to be a fallback temperature sensor, wherein the plurality of temperature sensors in the building are associated with a plurality of spaces within the building; and

receive user input indicating the fallback temperature sensor after prompting the user; and

processing circuitry configured to:

determine that the plurality of spaces within the building are unoccupied;

determine a temperature sensed by the fallback temperature sensor based on communication between the controller and the fallback temperature sensor;

cause the HVAC system to turn on or off based on the temperature at the fallback temperature sensor in response to determining that the plurality of spaces within the building are unoccupied;

at a time after determining that the plurality of spaces within the building are unoccupied, determine that at least one space of the plurality of spaces within the building is occupied;

determine a temperature at a first temperature sensor of the plurality of temperature sensors based on communication between the controller and the first temperature sensor, wherein the first temperature sensor is associated with the at least one space; and

cause the HVAC system to turn on or off based on the temperature at the first temperature sensor in response to determining that the at least one space within the building is occupied.

11. The controller of claim 10 , wherein the fallback temperature sensor is a selected fallback temperature sensor, and wherein the user interface is configured to prompt the user by presenting a recommended fallback temperature sensor to the user.

12. The controller of claim 11 , wherein the processing circuitry is configured to:

determine that the user interface has not received the user input; and

select the recommended fallback temperature sensor as the selected fallback temperature sensor in response to determining that the user interface has not received the user input.

13. The controller of claim 11 ,

wherein the controller comprises a thermostat of the HVAC system,

wherein the thermostat comprises an integrated temperature sensor, and

wherein the user interface is configured to present the recommended fallback temperature sensor by presenting the integrated temperature sensor to the user as the recommended fallback temperature sensor.

14. The controller of claim 11 ,

wherein the user interface is configured to receive the user input indicating that the user has not selected the recommended fallback temperature sensor as the selected fallback sensor temperature, and

wherein the processing circuitry is configured to:

cause the user interface to present indications of other temperature sensors of the plurality of temperature sensors in response to determining that the user has not selected the recommended fallback temperature sensor as the selected fallback temperature sensor; and

cause the user interface to prompt the user to select the fallback temperature sensor from the other temperature sensors.

15. The controller of claim 10 , wherein the processing circuitry is further configured to:

determine that a new temperature sensor has been added to the plurality of temperature sensors, and

cause the user interface is configured to prompt the user whether the new temperature sensor should be the fallback temperature sensor in response to determining that the new temperature sensor has been added to the plurality of temperature sensors.

16. The controller of claim 10 ,

wherein the user input indicates two or more fallback temperature sensors from the plurality of temperature sensors based on the user input,

wherein the processing circuitry is configured to determine the temperature at the fallback temperature sensor by determining temperatures at the two or more fallback temperature sensors based on communication between the controller and the two or more fallback temperature sensors, and

wherein the processing circuitry is configured to control the HVAC system by controlling the HVAC system based on an average value of the temperatures at the two or more fallback temperature sensors in response to detecting no occupancy in the plurality of spaces.

17. A controller for a heating, ventilation, and air conditioning (HVAC) system in a building, the controller comprising:

a user interface configured to:

prompt a user to choose a fallback temperature sensor from a plurality of temperature sensors by at least presenting an indication of a recommended fallback temperature sensor to the user; and

receive user input indicating a selected fallback temperature sensor from the plurality of temperature sensors in the building after prompting the user, wherein the plurality of temperature sensors in the building are associated with a plurality of spaces within the building; and

processing circuitry configured to:

determine that the plurality of spaces within the building are unoccupied;

determine a temperature sensed by the selected fallback temperature sensor based on communication between the controller and the selected fallback temperature sensor; and

cause the HVAC system to turn on or off based on the temperature at the selected fallback temperature sensor in response to determining that the plurality of spaces within the building are unoccupied.

18. A controller for a heating, ventilation, and air conditioning (HVAC) system in a building, the controller comprising:

a user interface configured to receive user input indicating a fallback temperature sensor from a plurality of temperature sensors in the building, wherein the plurality of temperature sensors in the building are associated with a plurality of spaces within the building; and

processing circuitry configured to:

determine that a new temperature sensor has been added to the plurality of temperature sensors;

cause the user interface is configured to prompt a user whether the new temperature sensor should be the fallback temperature sensor in response to determining that the new temperature sensor has been added to the plurality of temperature sensors;

determine that the plurality of spaces within the building are unoccupied;

determine a temperature sensed by the fallback temperature sensor based on communication between the controller and the fallback temperature sensor; and

cause the HVAC system to turn on or off based on the temperature at the fallback temperature sensor in response to determining that the plurality of spaces within the building are unoccupied.

19. The controller of claim 17 , wherein the processing circuitry is configured to:

determine that the user interface has not received the user input; and

select the recommended fallback temperature sensor as the selected fallback temperature sensor in response to determining that the user interface has not received the user input.

20. The controller of claim 17 ,

wherein the controller comprises a thermostat of the HVAC system,

wherein the thermostat comprises an integrated temperature sensor, and

wherein the user interface is configured to present the recommended fallback temperature sensor by presenting the integrated temperature sensor to the user as the recommended fallback temperature sensor.