Technology overview & market analysis of charge-air coolers (CACs)
The global market for light vehicle CACs is forecast to grow in volume terms by 40.44% from 2017 to 2022.
After-cooling, inter-cooling, or charge-air cooling are interchangeable terms describing the system responsible for removing excess heat from the air charging the cylinders. The temperature of the air when compressed by forced induction rises as the boost pressure increases. There is a drop in the density of the air due to the rise in temperature resulting in lower oxygen content. In certain turbocharged engines, the temperature of the air can increase up to 220°C. The CAC is a heat exchanger fitted between the turbocharger/supercharger and the engine air inlet manifold, which cools the air entering the engine, making it denser and more oxygen-rich. This allows more fuel to be burned in the cylinder, thus improving the combustion process and increasing the volumetric efficiency of the engine. Lowering the temperature of air also prevents premature ignition or detonation, which can occur owing to the higher cylinder combustion temperature caused by high temperature compressed air after forced induction. The higher cylinder temperatures can also lead to excessive wear, or cause heat damage to the engine block or piston.