A refrigerated trailer is also known as a reefer. As this video explains, it works by extracting hot air and returning cold air. The main components of the refrigerated trailer include the condenser, compressor, and evaporator. This cooling system has its own fuel source separate from the truck. This also means that the cooling system continues to function even with the truck switched off.
The cooling process begins with the compressor pulling gaseous refrigerant from the container and compressing it into a liquid.
From the compressor, the refrigerant moves to the condenser. The condenser is a heat exchanger, absorbing heat from the refrigerant through fan-based cooling. Next, the refrigerant moves inside the container through an expansion valve. The expansion valve controls the temperature of the container by controlling how much refrigerant gets into the container. From the valve, the refrigerant goes into the evaporator and rapidly expands into a gas. Lastly, a fan pulls air from the container over coils containing gaseous refrigerant. The refrigerant absorbs heat from the air leaving cool air behind, and the process repeats. It should be noted that refrigerated truck rental services only maintain the temperature inside the truck, not cool down the cargo.
