The selection of heat exchangers plays a crucial role in the capacity control of free cooling systems. The type and size of heat exchangers influence the system’s ability to transfer heat efficiently and effectively. For example, plate-and-frame heat exchangers offer higher heat transfer coefficients and are more suitable for free cooling applications, while shell-and-tube heat exchangers are more commonly used in traditional cooling systems. The heat exchanger selection also affects the system’s pressure drop, flow rates, and overall energy efficiency.