A Typical Walk-In Refrigerator or Freezer A cross section of a typical commercial walk-in refrigeration or freezer. Located on the ceiling of the room, are the evaporator and the expansion device. The air-cooled condenser and the compressor are located outside the room. The refrigerant continuously circulates from the compressor to the air-cooled condenser into the expansion device and through the evaporator and then back to the compressor.