Exam Question

### (a) Ingress of Air into the Freon System
**Concept:** Air, primarily composed of nitrogen, oxygen, and argon, is a non-condensable gas within the operating temperature and pressure range of a typical “Freon” (e.g., R-22) refrigeration system. Its presence severely impedes the system's efficiency and longevity.
* **Causes:**
* **Leaks on the Low-Pressure Side:** The most common cause is a leak on the suction side of the system (e.g., evaporator, suction line, compressor crankcase seal). When the compressor cycles off and the internal pressure drops below atmospheric, air can be drawn into the system.