主动冷却系统是指冷却系统消耗能量来冷却，与此相对的是被动冷却，冷却时不消耗能量。

常见的主动冷却会让冷媒循环热传，使热由一处带到另一处。冷媒可能是气体，例如电脑硬件冷却中用到的风冷，或是液体，像是汽车中的散热系统。若冷媒是液体，从引擎流到散热器时将热带到散热器，再经过散热器上的空气使冷媒冷却。

另一种主动冷却则是利用制冷循环。

An active cooling system is one that involves the use of energy to cool something, as opposed to passive cooling that uses no energy.

Such systems circulate a coolant to transfer heat from one place to another. The coolant is either a gas, such as in air cooling of computers, or a liquid such as in a car engine. In the latter case, liquid is pumped to transfer heat from the engine to the radiator, which in turn is cooled by passing air over it.