Refrigeration units inside fridge vans use similar technology. Absorb heat in an insulated airtight compartment and dissipate that heat outside of that compartment. The insulation used is one of the most crucial parts of the whole operation. It is vital that there is a thick, high-quality layer of insulation inside the load space because, unlike household fridges, refrigerated vans are outside for long periods of time in all ambient conditions, sometimes in direct sunlight, running on hot roads, and powered by heat-generating engines.
The most commonly used insulation used to insulate the load space is made of an extremely high-density polymer foam containing billions of tiny air bubbles. This slows down the ingress of heat into the load space. The better the insulation the more heat you can keep out and the more heat you stop going in, the less heat the refrigeration unit has to take out.
The mechanics of the unit are made up of the same basic components as a standard kitchen fridge. The aim is to absorb heat inside the load space and dissipate it in the atmosphere this will reduce the load space temperature.
The condenser – The chances are, this is the thing you’ve seen on the top of a refrigerated van and wondered just what it does. The Condenser has a coil inside with a series of tubes and fins. A bit like a car radiator. A fan (or fans) passes air over the condenser coil which is full of sealed refrigerant tubes. Inside the tubes, the hot gas condenses into a liquid refrigerant. Heat is dissipated here into the atmosphere. The cooled liquid refrigerant then passes to the evaporator.
The evaporator – Inside the load space is the evaporator. It is a series of tubes and fins called the evaporator coil (much like the condenser coil). The liquid refrigerant is metered into the coil through a valve. As it enters the coil tubes it evaporates at a very low temperature. Heat is absorbed in this point. A fan or fan then circulates air over the coil and into the load space reducing the internal temperature. The refrigerant gas exits as a low-pressure gas and returns to the compressor.
The compressor – This is the heart (pump) of the system. It takes low-pressure refrigerant gas from the evaporator, compresses it to a hot high-pressure gas, and forces it out to the condenser for the cooling cycle to start all over again.
In a nutshell, each element of the refrigeration unit works together to remove heat from inside the vehicle so that the product being transported can be held at the required temperature.
Refrigerated units in vans differ from standard kitchen fridges in the way that they are powered. Of course, household fridges are typically connected to a mains supply but that’s not practical for a van that’s on the road.
Generally, fridge vans will use a direct drive system with a compressor bolted directly to the side of the vehicle’s engine to power the unit whilst delivering goods. A direct drive system is generally considered an efficient and simple solution however; in some cases, fridge vans can also be powered by a separate mains-driven compressor called a “standby compressor”. A standby allows either pre-cooling of the load space, additional storage, or an onsite storage facility used for example on catering vehicles A standby system is a highly useful feature to make sure that any perishable goods left inside the
Commonly, fridge van temperature settings have a range between 0℃ to 8℃ while a freezer van is more or less consistently at around -18℃. There are three classes: Class A: Refrigerated vans equipped with a cooling system that allows the user to set a storage temperature between +12°C and 0°C inclusive