Method and apparatus for operating a thermostat to provide an automatic changeover

• US 20030056946A1
• Filed: 09/21/2001
• Published: 03/27/2003
• Est. Priority Date: 09/21/2001
• Status: Active Grant

• Current Assignee: Robert Louis Breeden
• Original Assignee: Robert Louis Breeden
• Inventors: Breeden, Robert Louis
• Granted Patent: US 6,681,848 B2
• Time in Patent Office: Days
• US Class Current: 165/238
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/65 for selecting an operating mode
• CPC Class Codes: G05D 23/1917 using digital means
• CPC Class Codes: G05D 23/1951 with control of the working time of a temperature controlling device

Abstract

A method and apparatus defines (302) a time period Ps following a completion of a demand for one of heating and cooling the time period sufficient to allow a sensed room temperature Tr measured (309) by a thermostat (500) to stabilize after the completion of the demand; and records (310) an evaluation temperature Te equal to the sensed room temperature measured at an end of the time period. The method and apparatus determines (318, 320, 324, 326), at a future time after recording the evaluation temperature, whether to allow an automatic changeover between heating and cooling modes, based upon a comparison of the evaluation temperature and the sensed room temperature measured at the future time.

Claims

1. A method of operating a thermostat to provide an automatic changeover from a current mode to a new mode, the current mode and the new mode being alternate ones of a heating mode and a cooling mode, the method comprising the steps of:

defining a time period following a completion of a demand for one of heating and cooling, said time period sufficient to allow a sensed room temperature measured by the thermostat to stabilize after the completion of the demand;

recording an evaluation temperature equal to the sensed room temperature measured at an end of said time period; and

determining, at a future time after the recording step, whether to allow the automatic changeover, based upon a comparison of said evaluation temperature and the sensed room temperature measured at said future time.

2. The method of claim 1, further comprising the step of

repeating the determining step until an occurrence of one of the automatic changeover and a next demand in the current mode.

3. The method of claim 1, further comprising the steps of:

defining a single setpoint temperature; and

utilizing the single setpoint temperature as a target temperature for both the heating mode and the cooling mode.

4. The method of claim 1, wherein, when the thermostat is in the heating mode, the determining step comprises the step of

switching to the cooling mode in response to the sensed room temperature becoming greater than the evaluation temperature by more than a predetermined margin.

5. The method of claim 1, wherein, when the thermostat is in the cooling mode, the determining step comprises the step of

switching to the heating mode in response to the sensed room temperature becoming less than the evaluation temperature by more than a predetermined margin.

6. The method of claim 1, further comprising the steps of:

defining first and second setpoint temperatures having values which are not restricted by each other;

utilizing the first setpoint temperature as a target temperature for the heating mode; and

utilizing the second setpoint temperature as the target temperature for the cooling mode.

7. The method of claim 1, wherein the determining step comprises the steps of:

detecting whether the automatic changeover to the new mode, when made, will cause an immediate demand for one of heating and cooling in the new mode; and

delaying the automatic changeover until the automatic changeover will cause the immediate demand in the new mode.

8. A thermostat for providing an automatic changeover from a current mode to a new mode, the current mode and the new mode being alternate ones of a heating mode and a cooling mode, the thermostat comprising:

a sensor for measuring a sensed room temperature;

a processor coupled to the sensor for defining a time period following a completion of a demand for one of heating and cooling, said time period sufficient to allow the sensed room temperature measured by the sensor to stabilize after the completion of the demand; and

a memory coupled to the processor for cooperating with the processor to record an evaluation temperature equal to the sensed room temperature measured at an end of said time period,

wherein the processor is programmed to make a determination, at a future time after recording the evaluation temperature, of whether to allow the automatic changeover, based upon a comparison of said evaluation temperature and the sensed room temperature measured at said future time.

9. The thermostat of claim 8, wherein the processor is further programmed to

repeat making the determination of whether to allow the automatic changeover, based upon the comparison of said evaluation temperature and the sensed room temperature measured at said future time, until an occurrence of one of the automatic changeover and a next demand in the current mode.

10. The thermostat of claim 8, further comprising

a user interface coupled to the processor for allowing a user to control the thermostat,

wherein the processor is further programmed to cooperate with the user interface to:

define a single setpoint temperature; and

utilize the single setpoint temperature as a target temperature for both the heating mode and the cooling mode.

11. The thermostat of claim 8, wherein the processor is further programmed, when the thermostat is in the heating mode, to

switch to the cooling mode in response to the sensed room temperature becoming greater than the evaluation temperature by more than a predetermined margin.

12. The thermostat of claim 8, wherein the processor is further programmed, when the thermostat is in the cooling mode, to

switch to the heating mode in response to the sensed room temperature becoming less than the evaluation temperature by more than a predetermined margin.

13. The thermostat of claim 8, further comprising

a user interface coupled to the processor for allowing a user to control the thermostat,

wherein the processor is further programmed to cooperate with the user interface to:

define first and second setpoint temperatures having values which are not restricted by each other;

utilize the first setpoint temperature as a target temperature for the heating mode; and

utilize the second setpoint temperature as the target temperature for the cooling mode.

14. The thermostat of claim 8, wherein the processor is further programmed to:

detect whether the automatic changeover to the new mode, when made, will cause an immediate demand for one of heating and cooling in the new mode; and

delay the automatic changeover until the automatic changeover will cause the immediate demand in the new mode.

15. A module for use in a thermostat including a sensor for measuring a sensed room temperature, the module for cooperating with the sensor to provide an automatic changeover from a current mode to a new mode, the current mode and the new mode being alternate ones of a heating mode and a cooling mode, the module comprising:

a processor for defining a time period following a completion of a demand for one of heating and cooling, said time period sufficient to allow the sensed room temperature measured by the sensor to stabilize after the completion of the demand; and

a memory coupled to the processor for cooperating with the processor to record an evaluation temperature equal to the sensed room temperature measured at an end of said time period,

wherein the processor is programmed to make a determination, at a future time after recording the evaluation temperature, of whether to allow the automatic changeover, based upon a comparison of said evaluation temperature and the sensed room temperature measured at said future time.

16. The module of claim 15, wherein the processor is further programmed to

repeat making the determination of whether to allow the automatic changeover, based upon the comparison of said evaluation temperature and the sensed room temperature measured at said future time, until an occurrence of one of the automatic changeover and a next demand in the current mode.

17. The module of claim 15,

wherein the thermostat further includes a user interface coupled to the processor for allowing a user to control the thermostat, and

wherein the processor is further programmed to cooperate with the user interface to:

define a single setpoint temperature; and

utilize the single setpoint temperature as a target temperature for both the heating mode and the cooling mode.

18. The module of claim 15, wherein the processor is further programmed, when the thermostat is in the heating mode, to

switch to the cooling mode in response to the sensed room temperature becoming greater than the evaluation temperature by more than a predetermined margin.

19. The module of claim 15, wherein the processor is further programmed, when the thermostat is in the cooling mode, to

switch to the heating mode in response to the sensed room temperature becoming less than the evaluation temperature by more than a predetermined margin.

20. The module of claim 15,

wherein the thermostat further includes a user interface coupled to the processor for allowing a user to control the thermostat, and

wherein the processor is further programmed to cooperate with the user interface to:

define first and second setpoint temperatures having values which are not restricted by each other;

utilize the first setpoint temperature as a target temperature for the heating mode; and

utilize the second setpoint temperature as the target temperature for the cooling mode.

21. The module of claim 15, wherein the processor is further programmed to:

detect whether the automatic changeover to the new mode, when made, will cause an immediate demand for one of heating and cooling in the new mode; and

delay the automatic changeover until the automatic changeover will cause the immediate demand in the new mode.