🔍 Key Concepts

• Basic refrigeration cycle and what the thermostat in a walk-in box is intended to control • Difference between a space thermostat and controls that protect the compressor or control refrigerant flow, such as superheat controls • Normal purpose of a solenoid valve in a walk‑in box system (what happens when it opens/closes)

💭 Think About

• Ask yourself: What is the MAIN goal of the walk‑in box thermostat—protecting equipment or maintaining a certain condition inside the box? • Think about where the sensing bulb or thermostat element is usually physically located in a walk‑in cooler installation. • Which of the four options sounds like something a service technician would adjust to make the box warmer or colder for stored products?

✅ Before You Answer

• Verify which option relates to the condition inside the box, not just inside the piping of the refrigeration circuit. • Check which parameters (inlet temp, outlet temp, superheat, box temp) are normally read by safety/efficiency controls versus customer‑set temperature controls. • Confirm your choice by imagining where the sensing device would be mounted: on the evaporator piping or out in the refrigerated compartment air.