How to choose a transport refrigeration unit

1. Cooling Capacity

• Load Assessment: The heat load must be calculated by taking into account the volume of the cargo space. Different types of transported goods possess distinct heat-generating qualities. For instance, perishable items like fruits, vegetables, and pharmaceuticals each have their own thermal characteristics. External temperature conditions also play a significant role. When transporting ice-cream, which requires extremely low temperatures, a greater cooling capacity is essential compared to transporting fresh vegetables. As a general guideline, the cooling capacity should be sufficient to maintain the desired temperature even under the most extreme ambient conditions.
• Safety Margin: It is recommended to incorporate a 10 – 20% safety margin into the calculated cooling capacity. This accounts for various unforeseen circumstances. During loading and unloading, door openings can lead to unexpected heat ingress. Additionally, during transportation, the external temperature might be higher than anticipated. This safety margin ensures that the refrigeration unit can handle such situations and maintain the required temperature.

2. Temperature Range and Precision

• Required Temperature: Different products have specific temperature needs. Frozen foods must be stored at approximately -18°C or lower to preserve their quality and safety. On the other hand, fresh produce such as lettuce and strawberries are typically maintained at around 0 – 4°C. It is of utmost importance to select a refrigeration unit that can accurately achieve and sustain the particular temperature range suitable for the cargo being transported.
• Temperature Control Precision: Certain goods, like vaccines and particular chemicals, demand highly precise temperature control. The refrigeration unit should be equipped with a thermostat or a sophisticated temperature-control system. This system should be capable of maintaining a consistent temperature within a narrow range, usually within ±1 – 2°C of the set point. Such precision is vital to ensure the integrity and effectiveness of these sensitive products.

3. Power Source and Energy Efficiency

• Energy-Efficient Design: Opt for units that exhibit high energy-efficiency ratings. This aspect is especially crucial for long-distance transportation, as it can lead to significant reductions in fuel costs. Features such as variable-speed compressors can adjust the cooling output according to the actual load, minimizing energy wastage. Well-insulated cabinets also contribute to better energy efficiency by reducing heat transfer. Moreover, the energy efficiency of the refrigeration unit can have an impact on the range of an electric vehicle if it is utilized for transportation.

4. Size and Weight

• Space Utilization: The physical dimensions of the refrigeration unit should be carefully selected to fit snugly within the available space in the vehicle’s cargo area. This is essential to avoid sacrificing excessive cargo-carrying capacity. Some units are designed to be mounted on the roof, side, or under the vehicle, allowing for the optimal use of interior space. Compact and modular designs are often favored for smaller vehicles, as they offer greater flexibility and space-saving benefits.
• Weight Considerations: The weight of the refrigeration unit is a critical factor. It can influence the vehicle’s payload capacity and fuel efficiency. It is necessary to ensure that the unit’s weight falls within the acceptable range specified by the vehicle’s specifications. Heavier units may necessitate a more powerful vehicle to transport them, and they can also accelerate wear and tear on the vehicle’s suspension and tires, leading to increased maintenance costs and potential safety risks.