These systems utilize air as the coolant. Four different types of cooling methods are preferred for these type systems in; external air wash, direct forced air, indirect force air and cooling via a fan. The electrical components in aircrafts are sealed in boxes.
- External air wash is the method of cooling the electronic by blowing air over the outside of the equipment compartment.
- Direct forced air is, often the most effusion method, the method of directly blowing air over the electrical component.
- Indirect forced air is the method where air is blown through a cold wall heat exchanger inside the box.