🔍 Key Concepts

• Function of a thermostatic expansion valve (TXV) in a vapor-compression refrigeration cycle • Difference between temperature control in a room/box and control of refrigerant condition at the evaporator outlet • Relationship between superheat and protection of the compressor from liquid slugging

💭 Think About

• Think about where the thermostatic expansion valve is located in the system and what variable it actually senses and responds to. • Consider what must be controlled at the outlet of each evaporator to ensure safe and efficient compressor operation in a multi-box system. • Ask yourself: does a TXV directly sense room air temperature, suction pressure at the compressor, or the temperature of the refrigerant leaving the evaporator?

✅ Before You Answer

• Identify what bulb or sensor on a TXV usually measures (what temperature and where). • Distinguish between space (room) thermostats and evaporator control devices – which one actually controls box temperature? • Verify which choice mentions superheat and how that relates to preventing liquid refrigerant from returning to the compressor.