Abstract: A compressor-condenser unit for use in a residential heating, ventilation, and air conditioning system includes a condenser orifice ring sized to receive one or more fan blades. The condenser orifice ring includes an annular member having an upstream edge and a downstream edge. The annular member includes a wall that flares outward at the upstream edge and flares outward at the downstream edge with a narrow middle section. The flare of the wall at the upstream edge is between 5 and 20 degrees from vertical, and the flare of the wall at the downstream edge is between 15 and 30 degrees from vertical. Other condenser orifice rings and systems are presented.

Abstract: Systems and methods for displaying a dynamic badge for accessing a facility are disclosed. The dynamic badge may include a display of one or more objects that change shape over time according to a predetermined pattern. The dynamic badge may visible at a specified distance (such as a social distancing limitation). The dynamic badge may be scanned or recognized by a scanning device at the specified distance to determine facility access for a user of the badge.

Abstract: Systems and methods for displaying a dynamic badge for accessing a facility are disclosed. The dynamic badge may include a display of one or more objects that change shape over time according to a predetermined pattern. The dynamic badge may visible at a specified distance (such as a social distancing limitation). The dynamic badge may be scanned or recognized by a scanning device at the specified distance to determine facility access for a user of the badge.

Abstract: A system and method are described that help in alleviating charge imbalance issues, especially in HVAC systems that are operable in both heating and cooling modes. In various embodiments a compensator is attached to the liquid line of an outdoor heat exchanger. A heater is attached to the compensator. During cooling operations the heater is turned on to help drive refrigerant out of the compensator. During heating operations the heater is turned off, allowing excess refrigerant to migrate to the compensator and alleviate high pressure in the system.

Abstract: In various implementations, a heat pump may include heating operations and defrost operations. The heat pump may monitor cycle time(s) for one or more of the operations. Defrost operation(s) in the heat pump may be automatically adjusted based at least partially on cycle times.

Abstract: A system and method are described that help in alleviating charge imbalance issues, especially in HVAC systems that are operable in both heating and cooling modes. In various embodiments a compensator is attached to the liquid line of an outdoor heat exchanger. A heater is attached to the compensator. During cooling operations the heater is turned on to help drive refrigerant out of the compensator. During heating operations the heater is turned off, allowing excess refrigerant to migrate to the compensator and alleviate high pressure in the system.

Abstract: In various implementations, a heat pump may include heating operations and defrost operations. The heat pump may monitor cycle time(s) for one or more of the operations. Defrost operation(s) in the heat pump may be automatically adjusted based at least partially on cycle times.

Abstract: One embodiment of the present disclosure comprises a method of managing defrost operations in HVAC systems. In one embodiment a primary defrost operation comprises allowing a cooling cycle of the heat pump and a secondary defrost operation comprises allowing fans of the heat pump to operate at a low speed.

Abstract: In various implementations, a heat pump may include heating operations and defrost operations. The heat pump may monitor cycle time(s) for one or more of the operations. Defrost operation(s) in the heat pump may be automatically adjusted based at least partially on cycle times.

Abstract: In various implementations, a heat pump may include heating operations and defrost operations. The heat pump may monitor cycle time(s) for one or more of the operations. Defrost operation(s) in the heat pump may be automatically adjusted based at least partially on cycle times.

Abstract: Frost may accumulate on a heat pump. In various implementations, a primary defrost operation and/or a secondary defrost operation may be utilized to remove at least a portion of the frost from the heat pump.

Abstract: A heat pump system includes a controller and a closed system that includes a condensing heat exchanger coil, an evaporating heat exchanger coil, a refrigerant and a compressor. The compressor is configured to compress the refrigerant, thereby causing the refrigerant to have a greater pressure in the condensing heat exchanger coil than in the evaporating heat exchanger coil. The controller is configured to perform a passive defrost of the evaporating heat exchanger coil. The passive defrost includes disabling the compressor and providing a bypass path between the condensing and evaporating heat exchanger coils that bypasses the compressor. The bypass path allows the refrigerant to flow from the condensing heat exchanger coil to the evaporating heat exchanger coil while the compressor is disabled.

Abstract: A heat pump system includes a controller and a closed system that includes a condensing heat exchanger coil, an evaporating heat exchanger coil, a refrigerant and a compressor. The compressor is configured to compress the refrigerant, thereby causing the refrigerant to have a greater pressure in the condensing heat exchanger coil than in the evaporating heat exchanger coil. The controller is configured to perform a passive defrost of the evaporating heat exchanger coil. The passive defrost includes disabling the compressor and providing a bypass path between the condensing and evaporating heat exchanger coils that bypasses the compressor. The bypass path allows the refrigerant to flow from the condensing heat exchanger coil to the evaporating heat exchanger coil while the compressor is disabled.