Which device works together with boilers to facilitate heat transfer?

The heat exchanger is integral to the efficient operation of a boiler system as it facilitates heat transfer between two or more fluids. In the context of a boiler, the heat exchanger allows the heat produced during the combustion of fuel to be transferred to the water or steam in the system without the two substances mixing. This separation is crucial for maintaining system integrity and safety while ensuring efficient energy transfer.

The design of a heat exchanger can vary, but its primary function is to optimize heat transfer efficiency, which is essential for heating applications. By using principles of thermodynamics, heat exchangers help improve the overall energy efficiency of heating systems, making them a key component in steam and hot water production.

While other devices in a boiler setup play significant roles—such as pumps for moving water, burners for generating heat, and filters for maintaining water quality—the heat exchanger specifically is the component that directly facilitates the heat transfer process, making it the correct answer in this context.