Patent ID: 11940189
Assignee: GOODMAN MANUFACTURING COMPANY LP
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A heating, ventilation, and air conditioning (HVAC) system operable to use a refrigerant to heat or cool an indoor space and comprising:
a compressor, an outdoor heat exchanger, an indoor heat exchanger, a bi-flow expansion device, and a four-way valve operable to flow the refrigerant through the bi-flow expansion device in a first direction in a cooling mode and in a second direction, opposite the first direction, in a heating mode;
a supply duct including a supply damper operable to control a supply airflow through the supply duct from the indoor heat exchanger to the indoor space;
a supply air temperature sensor positioned in the supply airflow;
a return duct including a return damper operable to control a return airflow through the return duct from the indoor space to the indoor heat exchanger;
a defrost duct extending between the supply duct and the return duct between the indoor heat exchanger and the supply and return dampers, the defrost duct including a defrost damper operable to control a defrost airflow through the defrost duct; and
a controller programmed to receive temperature measurements of the supply air from the supply air temperature sensor and selectively position the defrost damper, the supply damper, and the return damper into closed positions, fully open positions, and positions therebetween;
wherein in a defrost mode:
the four-way valve is operable to direct the refrigerant flow in the first direction through the outdoor heat exchanger to defrost the outdoor heat exchanger; and
the controller is operable to position the supply damper, the return damper, and the defrost damper based on the received temperature measurements of the supply air from the supply air temperature sensor to control the supply airflow, the return airflow, and the defrost airflow to flow between the supply duct, the return duct, and the indoor heat exchanger without substantially flowing into and substantially cooling the indoor space.