🔍 Key Concepts

• Refrigeration cycle basics – what should normally be cold vs. warm (suction line, liquid line, compressor body) • Effect of expansion valve operation on temperature/pressure in the evaporator and suction line • Difference between low refrigerant flow, no refrigerant flow, and excessive refrigerant flow

💭 Think About

• Think about what has to happen on the low‑pressure (suction) side of the system for the line to get so cold that moisture in the air will freeze on it. • Which condition would allow too much liquid or excessive cooling in the evaporator and suction line, rather than starving it? • For each choice, ask yourself: does this make the evaporator/suction line colder than normal, warmer than normal, or stop flow almost completely?

✅ Before You Answer

• Identify which option would most likely cause flooding of the evaporator/suction line rather than starving it. • Eliminate any option that would obviously reduce refrigerant flow to the evaporator to near zero (no cooling, therefore no frost). • Consider what happens to suction pressure and line temperature when the expansion valve fails in different positions.