Some items need to stay at a particular temperature to retain freshness. For example, fresh flowers, wine, and related products need to be kept at a specific temperature range when in transit. Refrigerated trucks control temperatures in storage compartments all the time when these items are on the road. This is a closed system, which keeps away any atmosphere and temperature from the outside.
The items meant for transport are put in a closed compartment. Its sides of the compartment are insulated with polymer foam. The insulation along with seals at the door creates a heat-free closed space. Then, a refrigerated system keeps the temperatures low in the compartment. This system is comprised of a compressor, a condenser, and an evaporator. A condenser is a curved pipe that is filled with a coolant fluid called a refrigerant. It helps absorb heat into the compartment, while the fluid circulates through the system. The fluid sucks the heat, becomes hot, and turns to a gaseous state.
The gas is transported to a condenser where it is compressed under high pressure. The compressed gas is turned into a liquid again. This liquid is then passed through the evaporator. This part takes in air from the outside and passes it through the compressed coolant fluid. In doing so, the coolant fluid is cooled, and heat expelled to the outside. In the process, the coolant turns into a gas and absorbs heat from the coils. At this point, the release of the coolant is metered to help in precise control of temperature. The process starts again with the coolant being transferred to the condenser. As the process is repeated continuously, the atmosphere inside the compartment gets colder with time.
Regulations Affecting Temperature Control
There are temperature guidelines across various industries to ensure the quality of the products is maintained along the supply chain. These regulations are part of the Hazard Analysis, Critical Control Point. HACCP is a management system that helps prevent contamination by biological, physical, and chemical hazards. There is also the Food Safety Modernization Act that requires precise temperature control on food in transit. The act states that if there is a failure in temperature control that may render the food unsafe, the food should not be distributed until it is determined to be safe. There are also regulations for temperature control requirements for ready-to-eat foods.
The World Health Organization has also standardized temperature ranges for various medicines and vaccines when in transit. It classifies packaging into three different classes. Class A requires that the temperature does not go above 80°C. Class B packaging should ensure that temperature in a package does not go above 300°C while Class C requires that temperatures are maintained between 300°C and 20°C.
Other industries, such as flowers have their temperature control regulations enforced by specific regulators. Companies in those industries need to determine the regulations that apply to their products. They should then work with temperature monitoring companies to help in ensuring temperature compliance both at the store or in transit. There should also be a team in place to monitor compliance with temperature requirements. Fortunately, there are several technologies such as wireless, temperature monitoring, temperature management systems and modern refrigeration that makes real-time temperature monitoring easy and possible around the clock.