A reefer trailer is a specialized trailer that works similar to a common fridge. This is how it works: A compressor, which functions like a miniature engine, is within the reefer trailer. By compressing a specific gas known as refrigerant, it creates a chilly liquid. Heat is produced as a result of this process. Next, the condenser receives the chilled liquid refrigerant. Using the surrounding air as a heat exchanger, the condenser lowers the temperature of the liquid refrigerant. This is comparable to how the radiator on a car cools the engine. After cooling, the liquid refrigerant is put under greater pressure before passing through a tiny valve and into the evaporator. The liquid refrigerant rapidly expands and turns back into a gas inside the evaporator. By absorbing heat from the interior air of the truck during the expansion process, a cooling effect is produced. It functions similarly to how water evaporates to cool your skin. The items kept inside the reefer trailer are then exposed to the cool air created by the evaporator, preserving the proper temperature. The trailer's coolness is more evenly distributed thanks to the air circulation. After absorbing heat, the refrigerant gas returns to the compressor to restart the cycle. The temperature inside the trailer is kept constant by this ongoing cycle of heat absorption, expansion, cooling, and compression. All of this is powered by the truck's diesel engine.