Superheat / Subcooling Decision
- Interactive decision labs
- Built by working technicians
- Path-based verifiable certificate
- Exam preparation only
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Commercial Refrigeration / RAC
~12 min
intermediate
The call
Walk-in cooler is running continuously and only reaching 42°F on a 35°F setpoint. Customer says it used to hold fine.
- Equipment
- Walk-in cooler, R-404A, TXV, remote condensing unit
- Ambient
- 90°F
- Site notes
- Coil is clear. Fans running. No obvious ice. Gauges are available.
Decision 1 of 4
The condensing unit is running non-stop in 90°F ambient and the box is stuck 7 degrees above setpoint.
What measurements do you take first?
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: 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: Natural Refrigerant Safe-Handling DecisionNext 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