A fluid direct contact heat exchanger having a contact chamber with a source fluid inlet provided by a source fluid inlet pipe, a source fluid outlet provided by a source fluid outlet pipe, a transfer fluid inlet provided by a transfer fluid inlet pipe, and a transfer fluid outlet provided by a transfer fluid outlet pipe. The source fluid and the transfer fluid have substantially different specific gravities and the source fluid and the transfer fluid are each insoluble in the other. The heat exchanger incorporates a heat transfer inducement element in the contact chamber which has a rotatable inducer shaft and a transfer accelerator element attached to the inducer shaft.

A fluid direct contact heat exchanger having a contact chamber with a source fluid inlet provided by a source fluid inlet pipe, a source fluid outlet provided by a source fluid outlet pipe, a transfer fluid inlet provided by a transfer fluid inlet pipe, and a transfer fluid outlet provided by a transfer fluid outlet pipe. The source fluid and the transfer fluid have substantially different specific gravities and the source fluid and the transfer fluid are each insoluble in the other. The heat exchanger incorporates a heat transfer inducement element in the contact chamber which has a rotatable inducer shaft and a transfer accelerator element attached to the inducer shaft.

An air conditioning system having a compact configuration may include an evaporator and a heater core that have a cylindrical shape. The evaporator defines a cavity. The heater core is positioned within the cavity such that the evaporator and the heater core are coaxially positioned with each other about a center axis. The heater core is configured to rotate about the center axis to draw in air.

Rotary heat exchangers can include a ride-along compressor, at least a portion of which can be rotated along with the heat exchanger. By rotating at least a portion of the compressor along with the heat exchanger, a sealed fluid circuit containing a two-phase working fluid can be provided. A rotary heat pump or heat engine can include an evaporator and a condenser in the form of back-to-back centrifugal fans. The centrifugal fan blades or other portions of the evaporator and condenser may include internal cavities where the working fluid undergoes a phase change.

Rotary heat exchangers can include a ride-along compressor, at least a portion of which can be rotated along with the heat exchanger. By rotating at least a portion of the compressor along with the heat exchanger, a sealed fluid circuit containing a two-phase working fluid can be provided. A rotary heat pump or heat engine can include an evaporator and a condenser in the form of back-to-back centrifugal fans. The centrifugal fan blades or other portions of the evaporator and condenser may include internal cavities where the working fluid undergoes a phase change.