Device to transfer heat between two physically separated fluids
* Counterflow heat exchanger: Heat exchanger in which fluids flow in opposite directions approximately parallel to each other
* Cross-flow heat exchanger: Heat exchanger in which fluids flow perpendicular to each other
* Heat pipe heat exchanger: See heat pipe
* Parallel-flow heat exchanger: Heat exchanger in which fluids flow approximately parallel to each other and in the same direction
* Plate heat exchanger or plate liquid cooler: Thin plates formed so that liquid to be cooled flows through passages between the plates and the cooling fluid flows through alternate passages