HVAC communication system

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.

A communication system, the communication system comprising:

• a. a communication device comprising a plurality of terminals configured to couple to a plurality of HVAC control wires, the plurality of terminals comprising at least a low-voltage AC input terminal and a Y-line terminal;
• b. a power supply coupled to the low-voltage AC input terminal, wherein power required to operate the communication system is drawn from the low-voltage AC input terminal;
• c. a control module coupled to the power supply;
• d. at least one switch coupled to the control module, wherein when the at least one switch is coupled between the low-voltage AC input terminal and the Y-line terminal;
• e. a communication module coupled to the control module;
• and
• f. a communication transformer coupled to the communication module, wherein a winding of the communication transformer is coupled serially with the Y-line terminal.

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.

A method of communicating across an HVAC system, the method comprising the steps of:

• a. providing a communication device coupled serially with at least one wire of the HVAC system;
• and
• b. inducing a current in the at least one wire;
• wherein the current comprises an AC current having a frequency of between 5 and 50 MHz.

A communication system, the communication system comprising:

• a. a communication device comprising a plurality of terminals configured to couple to a plurality of HVAC control wires, the plurality of terminals comprising at least a low-voltage AC input terminal and a Y-line terminal;
• b. a power supply connected to the low-voltage AC input terminal for providing power to the communication device;
• c. at least one switch connected serially between the low voltage AC input terminal and the Y-line terminal such that when the switch is closed a low-voltage AC signal is conducted to the Y-line terminal;
• d. a microprocessor capable of controlling the at least one switch;
• e. a communication module coupled to and in communication with the microprocessor;
• f. a communication transformer coupled to and in communication with the communication module, wherein the communication transformer comprises at least one winding that is serially coupled with the Y-line terminal;
• and
• g. a thermostat coupled to the communication device, wherein the communication device is configured to transmit an energy provider override request to the thermostat.