In an air conditioning system that uses a TXV, the evaporator outlet temperature relative to the inlet is usually

• A. Warmer than the evaporator inlet
• B. Colder than the evaporator inlet
• C. Equal to the evaporator inlet
• D. Not determinable without operating data

Answer: (A)

In an evaporator with a TXV, the refrigerant is there to absorb heat from the surrounding air. It enters the evaporator as a low‑pressure, cold liquid–vapor mixture and leaves as low‑pressure vapor that’s been heated and often superheated. Because heat is being transferred into the refrigerant, its temperature rises from the inlet to the outlet. The TXV helps maintain the right amount of refrigerant and a controlled superheat, but the basic flow is: cold inlet, warmer outlet after absorbing heat. So the evaporator outlet is warmer than the evaporator inlet.