TIME-BASED SETBACK RECOVERY

• US 20130153195A1
• Filed: 12/16/2011
• Published: 06/20/2013
• Est. Priority Date: 12/16/2011
• Status: Active Grant

• Current Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Original Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Inventors: Wallaert, Timothy E.
• Granted Patent: US 9,377,212 B2
• Time in Patent Office: Days
• US Class Current: 165/239
• 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 11/46 Improving electric energy efficiency or saving
• 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 11/63 Electronic processing
• CPC Class Codes: F24F 11/64 using pre-stored data
• CPC Class Codes: F24F 11/65 for selecting an operating mode
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: G05D 23/1904 variable in time

Abstract

A system controller of a heating, ventilation and air-conditioning system is configured to control the operation of a demand unit to maintain a comfort characteristic setpoint of a conditioned space. The controller includes a setback calculation module that is configured to calculate a setback value of the setpoint as a function of a recovery time from the setback value to the setpoint.

Claims

1. A heating, ventilation and air-conditioning system, comprising:

a system controller configured to control the operation of a demand unit to maintain a comfort characteristic setpoint of a conditioned space; and

a setback calculation module of said system controller configured to calculate a setback value of said setpoint as a function of a recovery time from said setback value to said setpoint.

2. The system as recited in claim 1, wherein said comfort characteristic setpoint is a setpoint temperature and said setback value is a setback temperature.

3. The system as recited in claim 1, wherein said system controller calculates said setback value from a historical rate of recovery.

4. The system as recited in claim 1, wherein said system controller and demand unit are components of a residential system.

5. The system as recited in claim 1, wherein said system controller and demand unit are components of a commercial rooftop system.

6. The system as recited in claim 1, wherein said setback calculation module is further configured to determine said time to recover as a function of measured local environmental conditions.

7. The system as recited in claim 6, wherein said local environmental conditions are selected from the group consisting of:

current indoor air temperature;

outdoor air temperature;

solar gain; and

outdoor wind speed.

8. The system as recited in claim 1, wherein said comfort characteristic is one of relative humidity and particulate concentration.

9. The system as recited in claim 1, wherein said system controller is configured to receive a user input value of said recovery time.

10. A method of manufacturing a heating, ventilation and air-conditioning system, comprising:

configuring a system controller to control the operation of a demand unit to maintain a comfort characteristic setpoint of a conditioned space; and

configuring a setback calculation module of said system controller to calculate a setback value of said setpoint as a function of a recovery time from said setback value to said setpoint.

11. The method as recited in claim 10, wherein said comfort characteristic setpoint is a setpoint temperature and said setback value is a setback temperature.

12. The method as recited in claim 10, wherein said system controller calculates said setback value from a historical rate of recovery.

13. The method as recited in claim 10, wherein said system controller and demand unit are components of a residential system.

14. The method as recited in claim 10, wherein said system controller and demand unit are components of a commercial rooftop system.

15. The method as recited in claim 10, wherein said system controller and demand unit are components of a refrigeration system.

16. The method as recited in claim 10, further comprising configuring said setback calculation module to determine said time to recover as a function of measured local environmental conditions.

17. The method as recited in claim 16, wherein said local environmental conditions are selected from the group consisting of:

current indoor air temperature;

outdoor air temperature;

solar gain; and

outdoor wind speed.

18. The method as recited in claim 10, wherein said comfort characteristic is one of relative humidity and particulate concentration.

19. The method as recited in claim 10, wherein said system controller is configured to receive a user input value of said recovery time.

20. A heating, ventilation and air-conditioning system controller, comprising:

a processor; and

a memory containing instructions,

wherein said instructions are configured to control the operation of a demand unit to maintain a comfort characteristic setpoint of a conditioned space, and to calculate a setback value of said setpoint as a function of a recovery time from said setback value to said setpoint.

21. The controller as recited in claim 20, wherein said comfort characteristic setpoint is a setpoint temperature and said setback value is a setback temperature.

22. The controller as recited in claim 20, wherein said instructions configure said processor to calculate said setback value from a historical rate of recovery.

23. The system as recited in claim 20, wherein said instructions configure said processor to receive a user input value of said recovery time.

24. A heating, ventilation and air-conditioning system controller, comprising:

a processor; and

a memory containing a data structure that correlates a recovery time of a comfort characteristic setpoint maintained by said processor with at least one measured local environmental condition,

wherein said processor is configured to update said data structure to maintain a comfort characteristic setpoint of a conditioned space, and to calculate a setback value of said setpoint as a function of said recovery time.

25. The controller as recited in claim 24, wherein said maintaining includes replacing said recovery time with a last measured recovery time.

26. The controller as recited in claim 24, wherein said processor is further configured to calculate said setback value as a function of an external environmental condition.