THERMOSTAT SYSTEM WITH SOFTWARE-REPURPOSABLE WIRING TERMINALS ADAPTABLE FOR HVAC SYSTEMS OF DIFFERENT RANGES OF COMPLEXITY

• US 20140084072A1
• Filed: 09/21/2012
• Published: 03/27/2014
• Est. Priority Date: 09/21/2012
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Nest Labs Incorporated (Alphabet Inc.)
• Inventors: Conner, Brian J., Palmer, Joseph E., Sloo, David
• Granted Patent: US 8,708,242 B2
• Time in Patent Office: Days
• US Class Current: 236/1.C
• 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 11/38 Failure diagnosis
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/523 for displaying temperature data
• CPC Class Codes: F24F 11/58 using Internet communication
• 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: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: G05D 23/1902 characterised by the use of a variable reference value
• CPC Class Codes: G05D 23/1919 characterised by the type of controller

Abstract

An auxiliary hardware box is described that can be installed at or near the HVAC system. The auxiliary box includes a large number of wiring terminals, for example 16 or more, for connecting to a relatively large number of HVAC control wires. The auxiliary box can include a “train map” type graphic display that is visible to the installer and provides a graphical indication as to which relays or switches are currently open and which are currently closed. A small sleek visually pleasing thermostat is also described that can be connected either directly to an HVAC system or to the auxiliary box, and can automatically detect an purpose the connected wires according to which it is connected to.

Claims

1. A thermostat adapted for direct connection either to a Heating, Ventilation, and Air Conditioning (HVAC) system or to an intermediate auxiliary HVAC control unit, the thermostat comprising:

a plurality of wiring terminals each adapted to make electrical connection with one of a plurality of control wires running between a first location where the thermostat is installed and a second location where the HVAC system is installed; and

processors and circuitry configured and programmed to communicate with the intermediate auxiliary HVAC control unit directly at the second location via one or more of the plurality of control wires connected to one or more of the plurality of wiring terminals, the intermediate auxiliary HVAC control unit being directly electrically connected to the HVAC system via a plurality of HVAC control wires, the processors and circuitry further configured and programmed to;

automatically determine whether the intermediate auxiliary HVAC control unit is installed, or whether the intermediate auxiliary HVAC control unit is not installed and the plurality of control wires are connected directly to both the plurality of wiring terminals and to the HVAC system;

operate in a first mode to control the HVAC system directly and receive electrical power directly from the HVAC system when the intermediate auxiliary HVAC control unit is not installed and the plurality of control wires are connected directly to both the plurality of wiring terminals and to the HVAC systems; and

operate in a second mode to control the HVAC system indirectly by electronically re-purposing at least one of the plurality of control wires such that the thermostat communicates with and receives electrical power from the intermediate auxiliary HVAC control unit when the intermediate auxiliary HVAC control unit is installed.

2. A thermostat according to claim 1 wherein the processors and circuitry are further programmed to communicate with the intermediate auxiliary HVAC control unit bi-directionally.

3. A thermostat according to claim 1 wherein the processors and circuitry are further programmed to automatically detect when the plurality of control wires are connected to the intermediate auxiliary HVAC control unit.

5. A thermostat according to claim 3 wherein the automatic detection is based at least in part on an assessment of which of the one or more wiring terminals have wires connected thereto.

6. A thermostat according to claim 1 wherein the HVAC system includes an air mover or furnace and the intermediate auxiliary HVAC control unit is mounted within 5 meters of the air mover or furnace.

7. A thermostat according to claim 6 wherein the intermediate auxiliary HVAC control unit is mounted directly on a housing of the air mover or furnace.

8. A thermostat according to claim 1 wherein the plurality of control wires used for connection between the wiring terminals and the intermediate auxiliary HVAC control unit is fewer in number than the plurality of HVAC control wires.

9. A thermostat according to claim 8 wherein the one or more of the plurality of control wires is at most four wires.

10. A thermostat according to claim 9 wherein the one or more of the plurality of control wires is at most three wires.

12. A thermostat according to claim 1 wherein the intermediate auxiliary HVAC control unit is capable of controlling a variable fan speed using a pulse-width-modulated control signal.

13. A thermostat according to claim 1 wherein the intermediate auxiliary HVAC control unit includes a graphic display visible to a human viewing the display, the display indicating to the human which of a plurality of HVAC control wires connecting the intermediate auxiliary HVAC control unit to the HVAC system are currently electrically connected to each other.

14. A thermostat according to claim 1 wherein the thermostat when mounted on a wall occupies no more than 100 square centimeters, and the plurality of wiring terminals are configured for tool-free wire connection.

4. (canceled)

11. (canceled)

15. A system for controlling an HVAC a Heating, Ventilation, and Air Conditioning (HVAC) system comprising:

a thermostat installed in a first location comprising;

a plurality of wiring terminals each adapted to make electrical connection with one of a plurality of control wires running between the first location and a second location where the HVAC system is installed; and

processors and circuitry configured and programmed to communicate with an intermediate auxiliary HVAC control unit via one or more of the plurality of control wires connected to one or more of the plurality of wiring terminals, the processors and circuitry further configured and programmed to;

automatically determine whether the intermediate auxiliary HVAC control unit is installed, or whether the intermediate auxiliary HVAC control unit is not installed and the plurality of control wires are connected directly to both the plurality of wiring terminals and to the HVAC system;

operate in a first mode to control the HVAC system directly and receive electrical power directly from the HVAC system when the intermediate auxiliary HVAC control unit is not installed and the plurality of control wires are connected directly to both the plurality of wiring terminals and to the HVAC system; and

operate in a second mode to control the HVAC system indirectly by electronically re-purposing at least one of the plurality of control wires such that the thermostat communicates with and receives electrical power from the intermediate auxiliary HVAC control unit when the intermediate auxiliary HVAC control unit is installed; and

the intermediate auxiliary HVAC control unit installed in the second location where the HVAC system is installed, the intermediate auxiliary HVAC control unit being directly electrically connected to the HVAC system via a plurality of HVAC control wires, the intermediate auxiliary HVAC control unit comprising;

a first set of auxiliary unit wiring terminals each adapted to make electrical connection with one of the plurality of control wires running between the first location and the second location;

a second set of auxiliary unit wiring terminals each adapted to make electrical connection with one of the plurality of HVAC control wires running between the intermediate auxiliary HVAC control unit and the HVAC system;

a plurality of relays used to open and close connections between conductors leading to the second set of auxiliary unit wiring terminals; and

a graphic display visible to a human viewing the display, the display indicating to the human a status of one or more of the plurality of relays so as to show to the human which of the second set of auxiliary unit wiring terminals are currently electrically connected to each other.

16. A system according to claim 15 wherein the graphic display includes a plurality of visible LEDs which indicate status of one or more of the relays.

17. A system according to claim 15 wherein the intermediate auxiliary HVAC control unit further comprises one or more wiring terminals adapted to make electrical connection to one or more wires leading to one or more remote temperature sensors.

18. A system according to claim 17 wherein the one or more remote temperature sensors measures one or more temperatures selected from a group consisting of:

outdoor air temperature, indoor air temperature and return air temperature.

19. A system according to claim 15 wherein the graphic display includes lines representing conductors silkscreened onto an external housing of the intermediate auxiliary HVAC control unit.

20. A system according to claim 15 wherein the intermediate auxiliary HVAC control unit further comprises a wireless communication module configured to wirelessly communicate with at least one other device located with an enclosure conditioned by the HVAC system.

21. A system according to claim 15 wherein the first set of auxiliary unit wiring terminals are further adapted to make connection to a second thermostat.

22. A system according to claim 21 wherein the second thermostat can be located in the second location and be temporarily connected for use in installation of and/or diagnostics relating to the intermediate auxiliary HVAC control unit.

23. A system according to claim 15 wherein the intermediate auxiliary HVAC control unit further comprises circuitry for generating a pulse-width-modulated control signal for controlling variable speed on an HVAC component.

24. A system according to claim 15 wherein the intermediate auxiliary HVAC control unit further comprises circuitry for supplying electrical power to the thermostat through the first set of wiring terminals, said electrical power not being switched in order to control HVAC functions.

25. A system according to claim 24 wherein the electrical power is DC electrical power.

26. (canceled)