HVAC communication system

• US 7,537,172 B2
• Filed: 12/06/2006
• Issued: 05/26/2009
• Est. Priority Date: 12/13/2005
• Status: Expired due to Fees

• Current Assignee: Itron, Inc.
• Original Assignee: Comverge Incorporated (Itron, Inc.)
• Inventors: Mueller, Carl J., Garozzo, James P., Smith, Bradley A., Ng, Howard, Barton, Mark Lee, Barrett, Cecil H., Huddleston, Paul Michael, Rossi, John F., House, Russell Thomas
• Primary Examiner(s): JIANG, CHEN WEN
• Application Number:
  US11/567,641
• Publication Number:
  US 20070131787A1
• Time in Patent Office: 902 Days
• Field of Search: 236/51, 236/1.C, 340/310, 340/310.17, 340/533, 340/538, 340/538.11, 340/538.16
• 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 11/33 to fire, excessive heat or smoke
• CPC Class Codes: F24F 11/47 Responding to energy costs
• CPC Class Codes: F24F 11/56 Remote control
• CPC Class Codes: F24F 11/63 Electronic processing
• 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 system comprising:

a. at least one HVAC load;

b. an air handler coupled to the at least one HVAC load; and

c. a communication device coupled between the at least one HVAC load and the air handler, the communication device comprising;

i. an input terminal electrically coupled to the air handler;

ii. a Y-terminal electrically coupled to the HVAC load;

iii. a power supply module coupled to the input terminal;

iv. a communication module coupled to the power supply module;

v. a first signal transformer coupled to the communication module, wherein one winding of the first signal transformer is coupled serially with the Y-terminal; and

vi.a switch, wherein when the switch is closed, the HVAC load actuates.

2. The HVAC system of claim 1, further comprising a second signal transformer coupled serially with the Y-terminal;

and a second communication device coupled to the second signal transformer.

3. The HVAC system of claim 2, wherein the HVAC load is selected from the group consisting of heat pumps, furnaces and air conditioners.

4. The HVAC system of claim 3, wherein the HVAC load comprises an air conditioner, wherein the air conditioner comprises a contactor coil, wherein a Y-line couples the Y-terminal with one winding of the contactor coil.

5. The HVAC system of claim 2, wherein the communication module communicates with the Y-communication unit by way of low-power current modulation at a frequency of one of between 8 and 10 MHz, between 18 and 25 MHz and between 44 and 46 MHz.

6. The HVAC system of claim 2, wherein the second communication device is configured to receive energy consumption information from a energy provider and to communicate the energy consumption information across the Y-line to the communication module, wherein when the energy consumption information matches a predetermined criterion, the control module executes an operation selected from opening the switch and closing the switch.

7. The HVAC system of claim 2, wherein the communication module is configured so as to retrieve a received signal strength from the second communication device, and, where the received signal strength is below a predetermined threshold, to increase a transmitted signal strength.

8. The HVAC system of claim 2, wherein the communication module is configured so as to retrieve a received signal strength from the Y-communication unit, and, where the received signal strength is above a predetermined threshold, to decrease a transmitted signal strength.

9. The HVAC system of claim 2, wherein the second communication device is configured to communicate with one of a public switched telephone network, a wireless wide area network and a local area network.

10. The HVAC system of claim 2, wherein the second communication device comprises PLC circuitry for communication across electrical wiring.