Patent attributes
A heat-pump system includes a compressor, an outdoor heating exchanger, an indoor heat exchanger, an expansion device, and a supplemental heater. The outdoor heat exchanger is in fluid communication with the compressor. The indoor heat exchanger is in fluid communication with the compressor. The expansion device is in fluid communication with the indoor and outdoor heat exchangers. The supplemental heater includes a burner and a working-fluid conduit. The burner is configured to burn a fuel and heat the working-fluid conduit. When the heat-pump system is operating in a heating mode, the indoor heat exchanger receives working fluid from the working-fluid conduit such that the working fluid flows from an outlet of the working-fluid conduit to an inlet of the indoor heat exchanger.
