How Do Refrigerated Trailers Work?

You understand the need for certain items to remain at cold temperatures. It makes perfect sense for things that can freeze or melt such as wine and ice cream respectively. But do you know how the reefer unit actually works? It’s an amazing feat to travel long distances and maintain a cold temperature for your cargo and this invention has been around for less than 100 years. Let’s take a look at how these reefer units actually function.

The Components

One thing to be aware of is that the refrigeration systems are a closed system. The idea behind refrigeration is to remove heat and maintain a steady temperature. Let’s review the major parts of the system.

The compressor is driven by a small engine within the reefer unit. First, the compressor draws in gaseous refrigerant and compresses it. The pressure inside liquefies the gas and the liquid refrigerant gives off heat to the body of the compressor and the surrounding air.

The condenser receives the liquid from the compressor. At this point the liquid is still warm and the heat is exchanged within the condenser. The heat from the liquid flows to the walls of the tubing and then outside to the attached fins. The fins present more surface area to cool outside air drawn through the condenser fan. This is similar to how a radiator cools an engine.

The evaporator is located in the trailer. The refrigerant that has now given up most of its heat to the condenser has turned into a cool liquid. The refrigerant is then released into the evaporator through a metering valve that works like a throttle to control the amount of cooling.

In the evaporator the refrigerant expands and becomes a gas. As it goes through this process it absorbs lots of heat from the surrounding finned coils, which transfers heat from air flowing over the fins to the refrigerant. The trailer is being cooled by giving up some of its heat to the evaporator. This entire process continues to repeat until the desired temperature is reached.

We must care about our drivers and we care about our clients. By providing you with high quality service and quality equipment we can ensure your freight is going to be delivered in a timely manner without complications. We hope you enjoyed our article about how refrigerated vans work and have a better understanding of how your inventory will stay cool.