AUTO TEST FOR DELTA T DIAGNOSTICS IN AN HVAC SYSTEM

• US 20140214212A1
• Filed: 01/25/2013
• Published: 07/31/2014
• Est. Priority Date: 01/25/2013
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Leen, Cary, Zywicki, Stan, Barton, Eric
• Granted Patent: US 10,094,585 B2
• Time in Patent Office: Days
• US Class Current: 700/276
• 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 11/49 ensuring correct operation, e.g. by trial operation or configuration checks
• CPC Class Codes: F24F 11/52 Indication arrangements, e.g. displays
• CPC Class Codes: F24F 11/58 using Internet communication
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2221/50 HVAC for high buildings, e.g. thermal or pressure differences
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05D 23/1902 characterised by the use of a variable reference value

Abstract

An HVAC controller may be programmed to initiate a delta T test in response to a request received from a user. The user may initiate the delta T test at the HVAC controller or via a remote device. In some cases, the HVAC controller may be configured to automatically execute a delta T test for each valid equipment stage combination of the HVAC system without receiving further input from the user and to determine both a run time and a stabilized delta T parameter value for each equipment stage combination. The HVAC controller may also record the delta T parameter value and run time for each test in the memory of the HVAC controller. The HVAC controller may be further configured to notify the user when testing for each/all equipment stage combination is complete.

Claims

1. An HVAC controller configured to control one or more components of an HVAC system, the HVAC controller comprising:

a memory;

an I/O block, for receiving one or more signals from the HVAC system including one or more signals related to a delta T parameter value of the HVAC system, and for providing one or more control signals to the HVAC system including one or more control signals to activate the HVAC system; and

a controller operatively coupled to the memory and the I/O block, the controller programmed to initiate a delta T test that is configured to;

provide one or more control signals to activate the HVAC system;

monitor the one or more signals related to the delta T parameter value;

determine when a rate of change of the delta T parameter value falls below a threshold value, indicating a stabilized delta T parameter value; and

record the stabilized delta T parameter value in the memory.

2. The HVAC controller of claim 1 further comprising a user interface, and wherein the delta T test is initiated in response to a request made by a user via the user interface.

3. The HVAC controller of claim 1, wherein the delta T test is further configured to:

monitor an elapsed time of the delta T test before the rate of change of the delta T parameter value falls below the threshold value; and

record the elapsed time in the memory.

4. The HVAC controller of claim 3 further comprising a user interface having display, wherein the controller is further programmed to repeatedly update and display the delta T parameter value and the elapsed time on the display of the user interface during the delta T test.

5. The HVAC controller of claim 1, further comprising a user interface having display, wherein the controller is further programmed to repeatedly update and display the delta T parameter value on the display during the delta T test.

6. The HVAC controller of claim 1, wherein the controller is further programmed to accept one or more installer set up parameters, and wherein at least one of the installer set up parameters corresponds to a number of equipment stages of the HVAC system.

7. The HVAC controller of claim 6, wherein the controller is further programmed to automatically execute the delta T test for each of two or more valid equipment stage combinations of the HVAC system without further input from a user.

8. The HVAC controller of claim 7, wherein the controller is further programmed to record a stabilized delta T for each of the two or more valid equipment stage combinations.

9. The HVAC controller of claim 8, wherein the delta T test is further configured to monitor an elapsed time until the rate of change of the delta T parameter value falls below the threshold value for each of the two or more valid equipment stage combinations, and records the corresponding elapsed times in the memory.

10. The HVAC controller of claim 1, wherein the controller is further programmed to display a notification on a display, notifying the user that the delta T test is complete.

16. The HVAC controller of claim 1, wherein the HVAC controller is a wireless thermostat that includes a temperature sensor.

11. An HVAC controller configured to control one or more components of an HVAC system, the HVAC controller comprising:

a memory;

an I/O block, for receiving one or more signals from the HVAC system including one or more signals related to a delta T parameter value of the HVAC system, and for providing one or more control signals to the HVAC system including one or more control signals to activate the HVAC system;

a user interface;

a controller operatively coupled to the memory, the I/O block and the user interface, the controller programmed to initiate a delta T test sequence in response to a request received via the user interface, and once initiated, to execute a delta T test for each valid equipment stage combination of the HVAC system, each delta T test including;

starting a timer to monitor an elapsed time;

providing one or more control signals to activate a first/next valid equipment stage combination of the HVAC system;

monitoring the one or more signals related to the delta T parameter value;

determining when a rate of change of the delta T parameter value falls below a threshold value, indicating a stabilized delta T parameter value at a stabilized elapsed time; and

recording the stabilized delta T parameter value and the stabilized elapsed time in the memory.

12. The HVAC controller of claim 11, wherein the controller further provides a notification via the user interface when the delta T test for all of the valid equipment stage combinations is complete.

13. The HVAC controller of claim 11, wherein the controller repeatedly updates and displays a current delta T parameter value on the user interface during the delta T test for each valid equipment stage combination of the HVAC system.

14. The HVAC controller of claim 13, wherein the controller repeatedly updates a current elapsed time on the user interface during the delta T test for each valid equipment stage combination of the HVAC system.

15. The HVAC controller of claim 11, wherein the controller records the stabilized delta T parameter value and the stabilized elapsed time in the memory for a first equipment stage combination before executing a delta T test for a second equipment stage combination.

17. A method of monitoring a performance of an HVAC system having one or more components controller at least in part by an HVAC controller, the HVAC controller having a memory and a controller, the method comprising:

providing one or more control signals from the HVAC controller to activate the HVAC system;

monitoring one or more signals from the HVAC system that are related to a delta T parameter value of the HVAC system;

determining when the delta T parameter value becomes stable, indicating a stabilized delta T parameter value; and

recording the stabilized delta T parameter value in the memory of the HVAC controller.

18. The method of claim 17, wherein the delta T parameter value becomes stable when the delta T parameter value changes by less than a predetermined amount over a predetermined amount of time.

19. The method of claim 18, further comprising:

determining a time that elapses before the delta T parameter value becomes stable; and

recording the elapsed time in the memory.

20. The method of claim 18, further comprising:

repeating the providing, monitoring, determining and recording steps for each of a plurality of equipment stage combination of the HVAC system.