Heat exchangers are devices that allow heat to be transferred between two or more fluids of different temperatures (vapors, liquids, or gases). The heat transfer process can be liquid-to-gas, gas-to-gas, or liquid-to-liquid, and it can happen through a solid separator or direct fluid contact, depending on the type of heat exchanger used. Other design features, such as construction materials and components, heat transfer processes, and flow configurations, aid in classifying and categorizing the various types of heat exchangers accessible. Heat exchanger makers offer a wide range of heat exchanging devices designed and manufactured for use in both cooling and heating processes and find applications across a wide range of industries.