CONTEXT ADAPTIVE COOL-TO-DRY FEATURE FOR HVAC CONTROLLER

• US 20140319231A1
• Filed: 04/26/2013
• Published: 10/30/2014
• Est. Priority Date: 04/26/2013
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Nest Labs Incorporated (Alphabet Inc.)
• Inventors: MATSUOKA, YOKY, FISHER, EVAN J.
• Granted Patent: US 9,696,735 B2
• Time in Patent Office: Days
• US Class Current: 236/51
• CPC Class Codes: F24F 3/1405 in which the humidity of the air is exclusively affected by contact with the evaporator of a closed-circuit cooling system or heat pump circuit
• CPC Class Codes: G05D 22/02 characterised by the use of electric means
• CPC Class Codes: G05D 23/1902 characterised by the use of a variable reference value
• CPC Class Codes: G05D 27/02 characterised by the use of electric means

Abstract

A thermostat may include one or more temperature sensors that provide temperature sensor measurements, a humidity sensor that provides humidity sensor measurements, an occupancy sensing system that may be used to characterize an occupancy status of an enclosure in which the thermostat is installed from among a plurality of possible occupancy statuses including an occupied state and an away state; and a processing system. The processing system may be configured to activate a cooling function of an HVAC system to reduce a humidity level in the enclosure based on a first set of conditions when the occupancy status is in the occupied state, or based on a second set of conditions when the occupancy status is in the away state.

Claims

1. A thermostat, comprising:

a housing;

a user interface;

one or more temperature sensors, each of the one or more temperature sensors being configured to provide temperature sensor measurements;

a humidity sensor configured to provide humidity sensor measurements;

an occupancy sensing system that characterizes an occupancy status of an enclosure in which the thermostat is installed from among a plurality of possible occupancy statuses including an occupied state and an away state; and

a processing system disposed within the housing, the processing system being configured to be in operative communication with the one or more temperature sensors to receive the temperature sensor measurements, in operative communication with one or more input devices including said user interface for determining a setpoint temperature, and in still further operative communication with a heating, ventilation, and air conditioning (HVAC) system to control the HVAC system based at least in part on the setpoint temperature and the temperature sensor measurements;

wherein said processing system is further configured to operate in conjunction with said occupancy sensing system to provide an occupancy-status-sensitive automated dehumidification feature comprising;

(i) an occupied-state automated dehumidification algorithm designed to operate according to combined comfort-and-humidity criteria characterized in that when the humidity sensor measurements are above a first humidity threshold, and the temperature sensor measurements are below the setpoint temperature, a cooling function of the HVAC system operates in order to reduce a humidity level in the enclosure until a first set of conditions are met; and

(ii) an away-state automated dehumidification algorithm designed to operate according to away-humidity criteria characterized in that when the humidity sensor measurements are above a second humidity threshold, and the temperature sensor measurements are below the setpoint temperature, the cooling function of the HVAC system operates in order to reduce the humidity level in the enclosure until a second set of conditions are met.

2. The thermostat of claim 1 wherein the occupied-state automated dehumidification algorithm and the away-state automated dehumidification algorithm are configured to wait for a first backoff interval after the first/second set of conditions are met before again activating the cooling function of the HVAC system in order to reduce the humidity level in the enclosure.

3. The thermostat of claim 2 wherein the occupied-state automated dehumidification algorithm and the away-state automated dehumidification algorithm are further configured to:

determine when a threshold number of dehumidification cycles to reduce the humidity level in the enclosure have occurred; and

wait for a second backoff interval after the first/second set of conditions are met before again activating the cooling function of the HVAC system in order to reduce the humidity level in the enclosure.

4. The thermostat of claim 3 wherein the second time interval is substantially longer than the first time interval.

5. The thermostat of claim 1 wherein the first set of conditions and the second set of conditions include a maximum time interval during which a dehumidification cycle may continue while the humidity sensor measurements are substantially similar.

6. The thermostat of claim 1 wherein the first set of conditions comprises a first temperature threshold below the setpoint temperature, and the second set of conditions comprises a second temperature threshold below the setpoint temperature.

7. The thermostat of claim 6 wherein the first humidity threshold is higher than the second humidity threshold, and the first temperature threshold below the setpoint temperature is higher than the second temperature threshold below the setpoint temperature.

8. The thermostat of claim 1 further comprising a wire insertion sensing system that automatically detects when a dehumidifier is connected to the thermostat, wherein the processing system is configured to deactivate the occupied-state automated dehumidification algorithm and the away-state automated dehumidification algorithm when the dehumidifier is detected.

9. A method of dehumidifying an enclosure using a cooling function of an HVAC system, the method comprising:

characterizing, using an occupancy sensing system of a thermostat, an occupancy status of the enclosure, the occupancy status being selected from among a plurality of possible occupancy statuses including an occupied state and an away state;

processing humidity sensor measurements provided by a humidity sensor of the thermostat, wherein the thermostat comprises;

a housing;

a user interface;

one or more temperature sensors, each of the one or more temperature sensors being configured to provide temperature sensor measurements;

the humidity sensor;

the occupancy sensing system; and

a processing system disposed within the housing, the processing system being configured to be in operative communication with the one or more temperature sensors to receive the temperature sensor measurements, in operative communication with one or more input devices including said user interface for determining a setpoint temperature, and in still further operative communication with a heating, ventilation, and air conditioning (HVAC) system to control the HVAC system based at least in part on the setpoint temperature and the temperature sensor measurements; and

operating, using a processing system of the thermostat, an occupancy-status-sensitive automated dehumidification feature comprising;

(i) an occupied-state automated dehumidification algorithm designed to operate according to combined comfort-and-humidity criteria characterized in that when the humidity sensor measurements are above a first humidity threshold, and the temperature sensor measurements are below the setpoint temperature, a cooling function of the HVAC system operates in order to reduce a humidity level in the enclosure until a first set of conditions are met; and

(ii) an away-state automated dehumidification algorithm designed to operate according to away-humidity criteria characterized in that when the humidity sensor measurements are above a second humidity threshold, and the temperature sensor measurements are below the setpoint temperature, the cooling function of the HVAC system operates in order to reduce the humidity level in the enclosure until a second set of conditions are met.

10. The method of claim 9 wherein the occupied-state automated dehumidification algorithm and the away-state automated dehumidification algorithm are configured to wait for a first backoff interval after the first/second set of conditions are met before again activating the cooling function of the HVAC system in order to reduce the humidity level in the enclosure.

11. The method of claim 10 wherein the occupied-state automated dehumidification algorithm and the away-state automated dehumidification algorithm are further configured to:

determine when a threshold number of dehumidification cycles to reduce the humidity level in the enclosure have occurred; and

wait for a second backoff interval after the first/second set of conditions are met before again activating the cooling function of the HVAC system in order to reduce the humidity level in the enclosure.

12. The method of claim 11 wherein the second time interval is substantially longer than the first time interval.

13. The method of claim 9 wherein the first set of conditions and the second set of conditions include a maximum time interval during which a dehumidification cycle may continue while the humidity sensor measurements are substantially similar.

14. The method of claim 9 wherein the first set of conditions comprises a first temperature threshold below the setpoint temperature, and the second set of conditions comprises a second temperature threshold below the setpoint temperature.

15. The method of claim 14 wherein the first humidity threshold is higher than the second humidity threshold, and the first temperature threshold below the setpoint temperature is higher than the second temperature threshold below the setpoint temperature.

16. The method of claim 9 further comprising determining whether a dehumidifier is connected to the thermostat using a wire insertion sensing system, wherein the processing system is configured to deactivate the occupied-state automated dehumidification algorithm and the away-state automated dehumidification algorithm when the dehumidifier is detected.

17. A thermostat comprising:

one or more temperature sensors that provide temperature sensor measurements;

a humidity sensor that provides humidity sensor measurements;

an occupancy sensing system that is used to characterize an occupancy status of an enclosure in which the thermostat is installed from among a plurality of possible occupancy statuses including an occupied state and an away state;

a processing system configured to activate a cooling function of an HVAC system to reduce a humidity level in the enclosure based on a first set of conditions when the occupancy status is in the occupied state, or based on a second set of conditions when the occupancy status is in the away state.

18. The thermostat of claim 17 wherein the first set of conditions comprises a temperature threshold, a humidity threshold, and a time interval based on user comfort considerations.

19. The thermostat of claim 17 wherein the second set of conditions comprises a temperature threshold, a humidity threshold, and a time interval based on efficiency and power saving considerations.

20. The thermostat of claim 17 wherein the processing system is further configured to activate the cooling function of the HVAC system to reduce the humidity level in the enclosure in a plurality of dehumidification cycles that are separated by backoff intervals.