Alex Roskoss, Global Head of Technical Services
There are two major ways to move temperature controlled products or payloads, passive provision or active provision of temperature control.
Active systems are what you typically think of as temperature control; freezers, fridges and cold rooms. When it comes to shipments, these active systems are typically just mounted on trailers, vans or pallets. They provide thermal control which actively responds to the adverse temperatures outside.
Passive systems are less obvious and most people would know them from coolers or chilly bins, combining ice or cool-packs with insulation to provide a fixed amount of thermal protection. Its ability to protect a payload depends upon the design and preparation of the passive system.
The choice between actives and passives involves a large number of factors including
- Level of protection required
- Need for power supply
- Availability for use
- Flexibility of your supply chain
- Extremities of external environment
When powered and handled correctly, active systems can provide a high level of thermal protection, advanced units being capable of both heating and cooling in response to low or high external temperatures. They typically consume fuel, use battery power, or require constant external power to operate. This imposes tight restrictions on handling and shipping. The scale of these systems is typically from single pallet to whole vehicles. For high utilisation of space on fixed shipping routes and with good handling agreements, active solutions provide a good level of protection. There are inefficiencies however when only small payloads need to be moved. The high initial costs for the units also pose a barrier to use. To ameliorate the inefficiency, suppliers often lease units to reduce the costs to the single customers while increasing the utilisation of the units.
The passive systems in contrast can be scaled from single vials to multi-pallet and once assembled for shipping can be sealed and sent without the need for power supply and typically without temperature aware handling. They can travel through a wide range of carriers and integrators. The thermal performance occurs irrespective of the handling or external environment so re-routing and flexible supply chains can be accommodated. The performance is determined by initial design and preparation, in contrast to active solutions, the duration of the thermal protection is finite. They are comparatively low unit cost and so can be held in stock to allow flexibility of supply. Not requiring special handling and being size versatile, if there are a large number of destinations for payloads, in differing quantities, the passive solutions can provide a very economic solution.
The choice between the active and passive solution, given an acceptable quality level, is best approached on a total cost of ownership model where the flexibility of provision, the security of supply to the market, the replacement and quality costs along with the shipping costs and thermal solution costs are all evaluated.