Hvac communication system

Abstract From the Canadian patent

A system for communicating across conventional HVAC wiring is provided. The system includes a communication device having a communication module capable of including low power high frequency current signals into a single control wire coupling such as a thermostat. 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 …