CO2 120 Properties of R744

CO₂ 120: CO₂ Thermodynamics, Properties & Transcritical Operation is a technical foundations course for refrigeration technicians, operators, and engineers seeking a deeper understanding of how CO₂ functions within modern systems. This course explains why CO₂ is both an environmentally advantageous refrigerant and a unique thermodynamic fluid that behaves differently from ammonia and synthetic refrigerants.

Learners begin with the fundamental reasons for using CO₂, including its environmental benefits, safety classification, and efficiency potential. The course then explains the critical point and triple point—two thermodynamic landmarks that drive system behavior and dictate when CO₂ enters transcritical operation.

Students gain a clear understanding of subcritical versus transcritical operation through detailed exploration of the R744 pressure‑enthalpy cycle. Concepts such as COP, EER, flash gas, compressor work, and gas‑cooler control are demystified and linked directly to system efficiency. Additional modules cover CO₂’s pressure and density properties, explaining why CO₂ systems use smaller compressors, different piping sizes, and specialized component ratings.

The course also reviews CO₂ safety fundamentals, material interactions, and the consequences of moisture contamination. Students learn why water creates acid and ice within CO₂ systems and how to prevent long‑term damage using filtration and proper evacuation.

Course Modules Include:

1. Why Use CO₂ (R744)
2. Critical Point & Triple Point
3. R744 and the Carnot / Transcritical Cycle
4. CO₂ Properties – Pressure
5. CO₂ Properties – Density
6. CO₂ Safety
7. Water in CO₂ Systems
8. Going Transcritical

By the end of CO₂ 120, students will have mastered the physical science behind CO₂ refrigeration and will be fully prepared for commissioning‑level training in CO₂ 220 and 320.