Method and apparatus for establishing a set back temperature for an environmental control system

• US 9,501,071 B2
• Filed: 02/14/2012
• Issued: 11/22/2016
• Est. Priority Date: 02/14/2011
• Status: Active Grant

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Shah, Rajendra K.
• Primary Examiner(s): Lo, Kenneth M
• Assistant Examiner(s): Alvarez, Olvin Lopez
• Application Number:
  US13/991,262
• Publication Number:
  US 20130325193A1
• Time in Patent Office: 1,743 Days
• Field of Search: 700276-277, 700299-300
• US Class Current: 1/1
• 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 11/47 Responding to energy costs
• CPC Class Codes: F24F 11/523 for displaying temperature data
• CPC Class Codes: F24F 11/61 using timers
• 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: G05D 23/19 characterised by the use of electric means G05D23/1393 takes precedence
• CPC Class Codes: G05D 23/1904 variable in time

Abstract

A method for establishing a set back temperature for an environmental control system includes entering an energy saver control phase having a predetermined time period, determine an effective thermal load for an environmental control zone, calculating a set-back temperature based on the effective thermal load for the environmental control zone and the predetermined time period, operating an environmental control device to establish and maintain the set-back temperature for a portion of the predetermined time period, and operating the environmental control device to establish a desired temperature substantially by an end of the predetermined time period.

Claims

1. A method for establishing a set back temperature for an environmental control system, the method comprising:

entering an energy saver phase having a predetermined time period;

determining an effective thermal load for an environmental control zone;

determining an effective thermal response of the environmental control zone, the effective thermal response representing a ratio of a net capacity of an environmental control device to a rate of change of temperature of the environmental control zone;

calculating a set-back temperature based on the effective thermal load for the environmental control zone, the effective thermal response of the environmental control zone and the predetermined time period;

operating an environmental control device to establish and maintain the set-back temperature for a portion of the predetermined time period; and

operating the environmental control device to establish a desired temperature substantially by an end of the predetermined time period.

2. The method of claim 1, wherein determining the effective thermal load of the environmental control zone includes setting a default effective thermal load value.

3. The method of claim 1, wherein calculating the set-back temperature includes calculating the set-back temperature based, in part, on estimated capacities and efficiencies of the environmental control system.

4. The method of claim 3, wherein calculating the set-back temperature includes setting a set-back temperature that does not exceed the set-back temperature limit.

5. The method of claim 1, further comprising:

establishing a set-back temperature limit.

6. The method of claim 1, wherein calculating the set-back temperature includes calculating a first set-back temperature for a first environmental control zone and a second set back temperature for a second environmental control zone, the first set-back temperature being independent of the second set-back temperature.

7. The method of claim 1, wherein operating the environmental control system to establish the desired temperature includes setting a recovery time period.

8. The method of claim 7, wherein setting the recovery time period includes determining a recovery time period in which maximum available recovery capacity is equal to total required recovery capacity.

9. The method of claim 7, wherein operating the environmental control system to establish the desired temperature includes operating the environmental control system at maximum available recovery capacity during a first recovery portion of the recovery time period and operating the environmental control system at a lower capacity during a second recovery portion of the recovery time period.

10. The method of claim 7, wherein operating the environmental control system to establish the desired temperature includes setting a target temperature that is distinct from the desired temperature, operating the environmental control system at a rate configured to establish the target temperature during a first recovery portion of the recovery time period, and operating the environmental control system at a rate configured to establish the desired temperature at a second recovery portion of the recovery time period.

11. A programmable control unit comprising:

a controller; and

a memory operatively connected to the controller, the memory including a computer readable program which, when executed by the controller, causes the controller to;

enter an energy saver control phase having a predetermined time period;

determine an effective thermal load for an environmental control zone;

determine an effective thermal response of the environmental control zone, the effective thermal response representing a ratio of a net capacity of an environmental control device to a rate of change of temperature of the environmental control zone;

calculate a set-back temperature based on the effective thermal load for the environmental control zone, the effective thermal response of the environmental control zone and the predetermined time period;

operate an environmental control device to establish and maintain the set-back temperature for a portion of the predetermined time period; and

operate the environmental control device to establish a desired temperature at an end of the predetermined time period.

12. The programmable control unit according to claim 11, wherein the computer readable program which, when executed by the controller, causes the controller to:

set a default effective thermal load value.

13. The programmable control unit according to claim 11, wherein the computer readable program which, when executed by the controller, causes the controller to calculate the set-back temperature based, in part, on estimated capacities and efficiencies of the environmental control system.

14. The programmable control unit according to claim 11, wherein the computer readable program which, when executed by the controller, causes the controller to:

calculate a first set-back temperature for a first environmental control zone and a second set back temperature for a second environmental control zone, the first set-back temperature being independent of the second set-back temperature.

15. The programmable control unit according to claim 11, wherein the computer readable program which, when executed by the controller, causes the controller to:

set a recovery time period to re-establish the desired temperature.

16. The programmable control unit according to claim 15, wherein the computer readable program which, when executed by the controller, causes the controller to:

determine a recovery time period in which maximum available recovery capacity is equal to total required recovery capacity to set the recovery time period.

17. The programmable control unit according to claim 15, wherein the computer readable program which, when executed by the controller, causes the controller to:

operate the environmental control system at maximum available recovery capacity during a first recovery portion of the recovery time period and operating the environmental control system at a lower capacity during a second recovery portion of the recovery time period to re-establish the desired temperature.

18. The programmable control unit according to claim 15, wherein the computer readable program which, when executed by the controller, causes the controller to:

set a target temperature that is distinct from the desired temperature;

operate the environmental control system at a rate configured to establish the target temperature during a first recovery portion of the recovery time period; and

operate the environmental control system at a rate configured to establish the desired temperature at a second recovery portion of the recovery time period to re-establish the desired temperature.

19. An environmental control system comprising:

a plurality of environmental control devices configured and disposed to condition an environmental control zone; and

a programmable control unit operatively connected to the plurality of environmental control devices, the programmable control unit including;

a controller; and

a memory operatively connected to the controller, the memory including a computer readable program which, when executed by the controller, causes the controller to;

enter an energy saver control phase having a predetermined time period;

determine an effective thermal load for an environmental control zone;

determine an effective thermal response of the environmental control zone, the effective thermal response representing a ratio of a net capacity of an environmental control device to a rate of change of temperature of the environmental control zone;

calculate a set-back temperature based on the effective thermal load for the environmental control zone, the effective thermal response of the environmental control zone and the predetermined time period;

operate an environmental control device to establish and maintain the set-back temperature for a portion of the predetermined time period; and

operate the environmental control device to establish a desired temperature at an end of the predetermined time period.

20. The environmental control system according to claim 19, wherein, the computer readable program, when executed by the controller, causes the controller to:

set a default effective thermal load value.

21. The environmental control system according to claim 19, wherein, the computer readable program, when executed by the controller, causes the controller to:

calculate the set-back temperature based, in part, on estimated capacities and efficiencies of the environmental control system.

22. The environmental control system according to claim 19, wherein, the computer readable program, when executed by the controller, causes the controller to:

calculate a first set-back temperature for a first environmental control zone and a second set back temperature for a second environmental control zone, the first set-back temperature being independent of the second set-back temperature.

23. The environmental control system according to claim 19, wherein, the computer readable program, when executed by the controller, causes the controller to:

set a recovery time period to re-establish the desired temperature.

24. The environmental control system according to claim 23, wherein, the computer readable program, when executed by the controller, causes the controller to:

determine a recovery time period in which maximum available recovery capacity is equal to total required recovery capacity to set the recovery time period.

25. The environmental control system according to claim 23, wherein, the computer readable program, when executed by the controller, causes the controller to:

operate the environmental control system at maximum available recovery capacity during a first recovery portion of the recovery time period and operating the environmental control system at a lower capacity during a second recovery portion of the recovery time period to re-establish the desired temperature.

26. The environmental control system according to claim 23, wherein, the computer readable program, when executed by the controller, causes the controller to:

set a target temperature that is distinct from the desired temperature;

operate the environmental control system at a rate configured to establish the target temperature during a first recovery portion of the recovery time period; and

operate the environmental control system at a rate configured to establish the desired temperature at a second recovery portion of the recovery time period to re-establish the desired temperature.