Method and system for automatically optimizing zone duct damper positions

• US 7,017,827 B2
• Filed: 07/13/2004
• Issued: 03/28/2006
• Est. Priority Date: 01/20/2004
• Status: Active Grant

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Shah, Rajendra K., Werbowsky, Laurie L., VanOstrand, William F.
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US10/889,735
• Publication Number:
  US 20050156050A1
• Time in Patent Office: 623 Days
• Field of Search: 236/49.3, 236/78.D, 236/1.B, 621/77, 621/79, 621/80, 622/98, 165/205, 165/209, 165/217, 700/276, 700/277, 700/278
• US Class Current: 236/1.00B
• CPC Class Codes: F24F 11/70 Control systems characterised by their outputs; Constructional details thereof
• CPC Class Codes: F24F 13/02 Ducting arrangements
• CPC Class Codes: F24F 3/0442 with volume control at a constant temperature
• CPC Class Codes: G05D 23/1934 each space being provided with one sensor acting on one or more control means

Abstract

A control is functional to perform a method of determining a maximum desired airflow for each of a plurality of zones in a multi-zone HVAC system, and an expected airflow to those zones. In part, these determinations are based upon an algorithm that calculates the relative size of the ducts leading to each of the zones. The expected and maximum airflows are compared for each of the zones, and if any zone has an expected airflow that exceeds its maximum airflow, certain steps are taken to reduce airflow to that zone.

Claims

1. An HVAC system including:

a temperature changing component to change the temperature of air;

ducts to supply air to a plurality of zones and a damper associated with said ducts leading to each of the zones;

controls for providing temperature set points and actual temperatures in the plurality of zones;

a system control determining information relative to the plurality of zones; and

said control calculating an expected airflow for each of the plurality of zones based upon said information, said control also storing a maximum airflow desired for at least some of said plurality of zones, and said control comparing said expected and said maximum airflows for said some of said plurality of zones and taking corrective action should an expected airflow exceed said maximum airflow of said some of said plurality of zones.

2. The HVAC system of claim 1, wherein said expected airflow is calculated based in part on a determination of duct sizes for said ducts leading to the plurality of zones.

3. The HVAC system of claim 1, wherein said control also storing a maximum airflow for each of the plurality of zones, and said control comparing said expected and said maximum airflows, and taking corrective action should an expected airflow exceed said maximum airflow for any of the plurality of zones.

4. The HVAC system of claim 2, wherein said maximum airflow is also determined utilizing said duct size for each of the ducts leading to the plurality of zones.

5. The HVAC system of claim 2, wherein airflow limits are set, and considered along with said duct sizes to calculate said maximum airflow.

6. The HVAC system of claim 5, wherein said airflow limits may be set by an operator.

7. The HVAC system of claim 1, wherein said control evaluates available options to reduce airflow to any zone wherein said expected airflow exceeds said maximum airflow.

8. The HVAC system as set forth in claim 7, wherein, as one option, said control considers whether the total airflow through the entire system may be reduced to achieve said reduction of airflow to any zone wherein said expected airflow exceeds said maximum airflow.

9. The HVAC system as set forth in claim 7, wherein, as one option, said control evaluates whether airflow to any of said plurality of zones can be increased to reduce airflow to any zone wherein said expected airflow exceeds said maximum airflow.

10. The HVAC system as set forth in claim 9, wherein said control first considers whether any unoccupied zone airflow can be adjusted to achieve said airflow increase.

11. The HVAC system as set forth in claim 10, wherein said control then considers whether any occupied zones can be adjusted to achieve said airflow increase.

12. An HVAC system including:

a temperature changing component to change the temperature of air;

ducts to supply air to a plurality of zones and a damper associated with said ducts leading to each of the zones;

controls for providing temperature set points and actual temperatures in the plurality of zones;

a system control determining information relative to duct sizes for said ducts leading to the plurality of zones; and

said control calculating a maximum airflow for each of the zones based at least in part on said duct sizes.

13. The HVAC system of claim 12, wherein said maximum airflow is calculated in part based on a determination of duct size for said ducts leading to the plurality of zones.

14. A method of operating an HVAC system comprising the steps of:

(1) providing an HVAC system including a temperature changing component to change the temperature of air, ducts to supply air from said temperature changing component to a plurality of zones, and providing a damper associated with each of said ducts leading to each of the zones, and providing a control for providing temperature set points and actual temperatures in each of the plurality of zones to a system control; and

(2) operating said HVAC system, and determining an expected airflow volume into each of the zones, and comparing said expected airflow volume to a maximum airflow volume for each of the zones, and taking corrective action should said actual airflow value exceed said maximum airflow value for any of the zones.

15. The method of claim 14, wherein said corrective action includes increasing airflow into another of the zones, should any of the zones have an expected airflow that exceeds said maximum airflow.

16. The method of claim 15, wherein airflow is increased into an unoccupied zone as a first step, if an unoccupied zone can have increased airflow.

17. The method of claim 16, wherein airflow is increased into an occupied zone, should the airflow not be able to be increased into an unoccupied zone.

18. The method of claim 17, wherein a capacity stage of said temperature changing equipment is reduced if airflow cannot be further increased into either an unoccupied zone or an occupied zone.

19. The method of claim 14, wherein said system control reduces total system airflow as said corrective action.

20. An HVAC system controller comprising:

a control receiving information relative to duct sizes for ducts leading to each of several zones associated with said control;

said control calculating a maximum airflow for each of the zones based upon said information; and

said control also calculating an expected airflow for each of the zones, and comparing said expected airflow to said maximum airflow for each of said zones.

21. The control as set forth in claim 20, wherein airflow limits are set, and considered along with the duct sizes to calculate said maximum airflow.

22. The control as set forth in claim 21, wherein said airflow limits may be set by an operator.

23. The control as set forth in claim 20, wherein said control also calculates an expected airflow for each of the zones, and compares said expected airflow to said maximum airflow for each of said zones.

24. The control as set forth in claim 20, wherein said control evaluating available options to reduce airflow to any zone wherein said expected airflow exceeds said maximum airflow.

25. The control as set forth in claim 24, wherein, as one option, said control considers whether the total airflow through that system may be reduce to achieve said reduction.

26. The control as set forth in claim 24, wherein, as one option, said control evaluates whether airflow to any of the zones can be increased to achieve said reduction.

27. The control as set forth in claim 26, wherein said control first considers whether any unoccupied zone set points can be adjusted to achieve said airflow increase.

28. The control as set forth in claim 27, wherein said control then considers whether any occupied zone set points can be adjusted to achieve said airflow increase.