HVAC communication system

• US 7,163,158 B2
• Filed: 12/13/2005
• Issued: 01/16/2007
• Est. Priority Date: 12/14/2004
• Status: Expired due to Fees

• Current Assignee: Emerson Electric Company, Itron, Inc.
• Original Assignee: Emerson Electric Company, Comverge Incorporated (Itron, Inc.)
• Inventors: Mueller, Carl J., Garozzo, James P., Smith, Bradley A., Ng, Howard, Barrett, Cecil H., Huddleston, Paul Michael, Rossi, John F., House, Russell Thomas, Barton, Mark Lee
• Primary Examiner(s): JIANG, CHEN WEN
• Application Number:
  US11/301,447
• Publication Number:
  US 20060124759A1
• Time in Patent Office: 399 Days
• Field of Search: 236/51, 236/1.C, 340/310.01, 340/310, 340/310.17, 340/533, 340/538, 340/538.11, 340/538.16, 340/310.02
• US Class Current: 236/51
• 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 11/47 Responding to energy costs
• CPC Class Codes: F24F 11/56 Remote control
• CPC Class Codes: F24F 11/59 for presetting
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 11/70 Control systems characterised by their outputs; Constructional details thereof
• CPC Class Codes: F24F 11/88 Electrical aspects, e.g. circuits

Abstract

A system for communicating across conventional HVAC wiring is provided. The system includes a communication device having a communication module capable of inducing low power, high frequency current signals into a single control wire coupling, for example, a thermostat with a compressor. The communication module includes a power supply module that draws power sufficient to operate the communication module from the existing HVAC wiring, so as to eliminate any need for batteries or external power sources. A second communication module may be coupled to the single control wire. The second communication module operates as a transceiver sending communication signals to, and receiving communication signals from, the communication module. In one embodiment, the communication module is disposed within a building, for example coupled to an electronic thermostat, while the second communication module is disposed outside the building near the compressor. The communication signals are RF modulated signals between 5 and 50 MHz so as to take advantage of and pass across parasitic capacitances found inherent in transformers or other coils disposed within HVAC loads.

Claims

1. A HVAC communication system comprising:

a. a control module; and

b. a communication module coupled to the control module;

wherein the communication module is configured to communicate through the HVAC communication system by inducing current onto one HVAC control wire, wherein the current has a frequency of between 4 and 50 MHz.

2. The HVAC communication system of claim 1, wherein the HVAC system operates in conjunction with a HVAC load, further wherein the communication module comprises a communication transformer coupled serially with the control module and the HVAC load.

3. The HVAC communication system of claim 2, further comprising:

a. a thermal sensing element coupled to the control module;

b. at least one switch responsive to the thermal sensing element; and

c. a low-voltage AC input terminal coupled to the control module;

wherein when the at least one switch is closed, the HVAC load is actuated.

4. The HVAC communication system of claim 3, further comprising a power supply module coupled to the low-voltage AC input terminal, wherein the power supply module receives an amount of power from the low-voltage AC input terminal sufficient to operate the control module and the communication module.

5. The HVAC communication system of claim 4, wherein the amount of power is less than a predetermined threshold.

6. The HVAC communication system of claim 4, wherein the amount of power is less than 55 milliwatts.

7. The HVAC communication system of claim 2, further comprising:

a. a thermostat coupled to the control module; and

b. a HVAC load coupled to the thermostat by way of a single wire running from a coil disposed within the HVAC load to one of the control terminal and the thermostat.

8. The HVAC communication system of claim 7, further comprising a second control module and a second communication module having a second communication transformer coupled serially with the single wire.

9. The HVAC communication system of claim 8, wherein the control module is coupled with the thermostat and is disposed within a building, further wherein the HVAC load and the second communication module are disposed outside the building.

10. The HVAC communication system of claim 8, wherein when the communication module is actuated, a communication signal is transmitted across the single wire and is received by the second communication module.

11. The HVAC communication system of claim 8, wherein when the second communication module is actuated a second communication signal is transmitted across the single wire and is received by the communication module.