Heat exchangers are a key component of most advanced cooling systems as they enable the heat transfer from within the system into the ambient environment or another system. Within the heat exchanger, working fluids are mechanically separated in a way that allows heat to transfer from one to the other so that the heat can be dissipated elsewhere. Heat exchangers are typically comprised of heat transfer fins to maximize surface contact and highly engineered channels to optimize fluid flow.
Heat exchangers are used across all industries in a wide variety of applications and are essential to many facets of everyday life. They can be constructed in a diverse range of materials, fluids, and configurations to allow for maximum design flexibility and scalability as well as efficiency. The three most common types of heat exchangers are liquid to air, air to air, and liquid to liquid.
Liquid to Air
Liquid to air heat exchangers are the most common and can be found in a number of applications and industries ranging from consumer electronics and data centers to recreational and commercial vehicles used for mining, transportation, or defense. Cooling systems utilizing liquid to air heat exchangers are ideal for high power cooling and can be used anywhere with high density heat loads from CPU/GPU cooling to IGBTs and beyond.
Air to Air
Air to air heat exchangers are commonly used in electrical enclosures, particularly where electronics are sensitive to the environment. Air to air heat exchangers enable ruggedized systems by sealing complex or sensitive electronics from environmental hazards such as dust, particulates, and liquids. Air to air also allows for more flexibility in design as they can be natural convection or forced convection and by integrating two phase cooling, engineers can improve heat transfer for both passive and active cooling.
Air to air heat exchangers are often associated with HVAC systems. HVAC (Heating, Ventilation, and Air Conditioning) systems are essential for environmental control in building and vehicles as they provide both temperature management and air quality control. Keeping the air streams separate prevents external particles and outside contaminants from entering the system, while still allowing for sufficient control over air temperature.
Liquid to Liquid
Liquid to liquid heat exchangers are often used in applications such as vehicles, aerospace, and defense where there are already multiple working fluids within the application that may need to be cooled and/or heated for optimized performance. An example would be using a liquid to liquid heat exchanger in an aircraft that uses hot oil from the engine to heat the fuel for maximum fuel efficiency.
Other Types of Heat Exchangers
Air to liquid heat exchangers are much less common than liquid to air, but can be used in industrial processes where there is a waste of energy/heat that can be recovered and put to use which saves time and money.
Phase change heat exchangers are used for specialty applications that require consistent temperatures or have extremely high heat flux such as advanced servers or CCD cooling. Similar to thermosiphons, phase change heat exchangers utilize evaporators and condensers to enable two phase cooling, however they do not rely on gravity for transporting fluids. Aavid is the global leader in the design and manufacture of these more complex systems.