System and method for heating and cooling

An HVAC system for providing conditioned air to a structure, comprising:

• an outdoor unit configured to operate a compressor at variable speeds;
• a plurality of indoor units configurable to provide conditioned air to the structure, wherein the plurality of indoor units comprises;
• a ducted indoor unit comprising a first expansion valve for controlling refrigerant flow;
• and
• at least one duchess indoor unit comprising a second expansion valve for controlling refrigerant flow;
• and
• a gas furnace;
• wherein a controller of the outdoor unit communicates with a controller of the at least one ductless indoor unit via a first communication protocol, wherein a controller of the ducted indoor unit communicates via a second communication protocol, and wherein translation circuitry in communication with at least one of the controller of the outdoor unit and the at least one ductless indoor unit and in communication with the controller of the ducted indoor unit includes translation features configured to translate between the first and second communication protocols, facilitating communication between the ducted and the at least one duchess indoor unit.

An HVAC system for providing conditioned air to a structure, comprising:

• an outdoor unit configured to operate a compressor at variable speeds;
• a plurality of indoor units configurable to provide conditioned air to the structure, wherein the plurality of indoor units comprises;
• a ducted indoor unit comprising a first expansion valve for controlling refrigerant flow;
• and
• a ductless indoor unit comprising a second expansion valve for controlling refrigerant flow;
• a gas furnace;
• and
• a controller that receives an input indicative of a dew-point temperature at which moisture in the air surrounding in HVAC system may condense, wherein the controller is configured to operate the HVAC system to increase the temperature of the liquid refrigerant that is in a refrigerant line coupling at least one of the indoor units to the outdoor unit and that is downstream of a heat exchanger of the HVAC system operating as a condenser based on the input indicative of a dew-point temperature.

An HVAC system for providing conditioned air to a structure, comprising:

• an outdoor unit configured to operate a compressor at variable speeds;
• a plurality of indoor units configurable to provide conditioned air to the structure, wherein the plurality of indoor units comprises;
• a ducted indoor unit comprising a first expansion valve for controlling refrigerant flow;
• and
• a ductless indoor unit comprising a second expansion valve for controlling refrigerant flow;
• a gas furnace;
• and
• an oil-recovery system configured to estimate an amount of stray oil in the HVAC system based on the flow rate of refrigerant in a refrigerant line coupling at least one of the indoor units to the outdoor unit.