Natural Refrigerant Safe-Handling Decision
- Interactive decision labs
- Built by working technicians
- Path-based verifiable certificate
- Exam preparation only
- Worldwide online
Commercial Refrigeration / RAC
~11 min
intermediate
The call
You are called to a small commercial site that has a new hydrocarbon (R-290) reach-in and a CO₂ (R-744) system in the same building. You must decide safe working practice before starting diagnosis.
- Equipment
- R-290 reach-in + R-744 (CO₂) system present on site
- Ambient
- 78°F
- Site notes
- Enclosed plant area. Limited ventilation. No prior hydrocarbon or CO₂ experience recorded for the last tech.
Decision 1 of 4
The plant area is enclosed with limited ventilation and two very different refrigerants on site.
Before opening any circuit, what is the first requirement?
Where this lab sits
This is one module lab from Commercial Refrigeration / RAC. The full path adds sealed systems, defrost, rack-system orientation and natural-refrigerant safety, each ending in a lab like this one.
Open the full pathNext lab: Residential No-Cool — Split System Not CoolingNext lab: Residential No-Heat — Gas Furnace Short Cycling on IgnitionNext lab: Frozen Coil / Airflow RestrictionNext lab: Superheat / Subcooling DecisionNext lab: Walk-in Cooler Not Holding TemperatureNext lab: Ice Machine Not Making IceNext lab: Reach-in / Prep Table Not Holding TemperatureNext lab: Walk-in Freezer Defrost FaultNext lab: Rooftop Unit Not CoolingNext lab: RTU Economizer Stuck — No Free CoolingNext lab: RTU High Static — Low Airflow and Poor CoolingNext lab: RTU Gas Heat — No Heat / Ignition Fault