Abstract: The disclosed technology includes an air system including a first interlaced microchannel heat exchanger and a second interlaced microchannel heat exchanger. The air system can include a plurality of fluidly separated refrigerant circuits, and each of the refrigerant circuits can be configured to flow through the first interlaced microchannel heat exchanger and the second interlaced microchannel heat exchanger. The first interlaced microchannel heat exchanger can be located indoors, and the second interlaced microchannel heat exchanger can be located outdoors. Each of the refrigerant circuits can include its own compressor and expansion valve.

Abstract: The present disclosure provides a venturi system formed of a plurality of venturi portions, each of the plurality of venturi portions having an exterior surface, an interior surface having a generally convex profile, a first end, and a second end, wherein each of the plurality of venturi portions generally forms an arc of a circle and the first end of each of the plurality of venturi portions is configured to attach to the second end of an adjacent venturi portion to form the venturi system, wherein the venturi system is generally circular.

Abstract: The disclosed technology includes an air system including a first interlaced microchannel heat exchanger and a second interlaced microchannel heat exchanger. The air system can include a plurality of fluidly separated refrigerant circuits, and each of the refrigerant circuits can be configured to flow through the first interlaced microchannel heat exchanger and the second interlaced microchannel heat exchanger. The first interlaced microchannel heat exchanger can be located indoors, and the second interlaced microchannel heat exchanger can be located outdoors. Each of the refrigerant circuits can include its own compressor and expansion valve.

Abstract: The disclosed technology includes an air system including a first interlaced microchannel heat exchanger and a second interlaced microchannel heat exchanger. The air system can include a plurality of fluidly separated refrigerant circuits, and each of the refrigerant circuits can be configured to flow through the first interlaced microchannel heat exchanger and the second interlaced microchannel heat exchanger. The first interlaced microchannel heat exchanger can be located indoors, and the second interlaced microchannel heat exchanger can be located outdoors. Each of the refrigerant circuits can include its own compressor and expansion valve.

Abstract: A heat exchanger having a first heat exchanger tube and a second heat exchanger tube is disclosed. The first heat exchanger tube can have a first leg, a second leg, and a bend section, and the bend section of the first heat exchanger tube can include three or more bends, each of the three or more bends having a corresponding bend angle that is less than or equal to approximately 90 degrees. The second heat exchanger tube can have a first leg, a second leg, and a bend section, and the bend section of the second heat exchanger tube can include three or more bends, each of the three or more bends having a corresponding bend angle that is less than or equal to approximately 90 degrees.

Abstract: A heat exchanger having a first heat exchanger tube and a second heat exchanger tube is disclosed. The first heat exchanger tube can have a first leg, a second leg, and a bend section, and the bend section of the first heat exchanger tube can include three or more bends, each of the three or more bends having a corresponding bend angle that is less than or equal to approximately 90 degrees. The second heat exchanger tube can have a first leg, a second leg, and a bend section, and the bend section of the second heat exchanger tube can include three or more bends, each of the three or more bends having a corresponding bend angle that is less than or equal to approximately 90 degrees.

Abstract: Disclosed herein are heat exchanger system comprising: a refrigerant; a phase-changing material in thermal communication with the refrigerant; and a valve configured to selectively permit an amount of the refrigerant to flow through the heat exchanger system, the amount of the refrigerant being based on a temperature difference between the refrigerant and the phase-changing material. Also disclosed herein are methods of using the same.

Abstract: A heat exchange tube for an HVAC system can include at least one reduced diameter section with an integral flattened ridge. The flow of combustion gases through the heat exchanger tubes may be partially constricted inside the reduced diameter sections. When installed in an HVAC system the integral flattened ridges may be angled to intercept the flow of air outside the heat exchanger tubes.

Abstract: A heat exchange tube for an HVAC system can include at least one reduced diameter section with an integral flattened ridge. The flow of combustion gases through the heat exchanger tubes may be partially constricted inside the reduced diameter sections. When installed in an HVAC system the integral flattened ridges may be angled to intercept the flow of air outside the heat exchanger tubes.