When Erika Mustermann peels her weekly groceries out of their insulated packaging, she doesn't think about how much planning went into that delivery - and that's a good thing: Last-mile delivery is all about making the end customer happy. But for Erika to be happy, the temperature-controlled logistics must overcome numerous challenges - and in the end, the cost-benefit calculation should also be right! We show why conventional insulating packaging is not ideal for passive refrigerated logistics and what the alternative is.

Packaging in refrigerated logistics - active vs. passive

How do frozen goods actually get to the supermarket? And how is it that lamb's lettuce still looks as freshly picked after several hours in the truck? In fact, transporting food, medicines and other temperature-sensitive goods is a logistical tour de force. Depending on the nature of the products, specific temperature corridors must be constantly maintained - regardless of whether the carrier has to wait for suppliers, has a flat tire or gets stuck in rush hour. Customers expect fresh goods and smooth service.

In order to protect consumers, there are national, EU-wide and global legal requirements for temperature-controlled transport.

Guidelines such as the HACCP concept and the ATP(Agreement on the International Carriage of Perishable Foodstuffs) are intended to standardize temperature-controlled food transport in particular. We take a look at which requirements have to be met in this area.

Transport along the cold chain

From the manufacturer to the wholesaler, from the wholesaler to the intermediary, from the intermediary to the retailer or directly on to the end customer: before temperature-sensitive goods land in our refrigerators and medicine cabinets, they sometimes have the proverbial world tour behind them. To ensure that the products nevertheless arrive at their destination at the correct temperature, retail and logistics companies are required to to maintain the cold chain obligated.

The cooling or refrigeration chain begins at the latest when the products are picked or made available for removal. The responsible company must ensure that

• all goods to be transported are at the prescribed temperature at the time of departure.
• the packaging or the transport containers guarantee the maintenance of the prescribed temperature.
• the temperature of the goods is controlled at each station of the transport route and finally at the handover to the recipient(interface control)

Deviations of more than+/- 3 degrees Celsius from the respective prescribed temperatures are not permitted under European law and are considered an interruption of the cold chain. To ensure continuous cooling and to be able to transport temperature-controlled products in accordance with the regulations, companies have a choice between two different systems: active cooling and passive cooling.

Active and passive cooling in temperature-controlled transport

Classically, temperature-sensitive products are transported with the help of refrigerated fleets. These are vehicles, usually trucks, that are equipped with a power-supplied refrigeration unit that keeps the temperature in the cargo hold constantly within the desired temperature range. In this context, we also speak of active cooling:

The unit runs on the vehicle battery and there is a continuous recording of temperature and humidity data. This data can be read on a display. Active cooling of temperature-sensitive food and products is effective, but corresponding systems also have some disadvantages:

• High costs: Refrigerated vehicles with permanently installed units are expensive to purchase and costly to operate.
• High damage sums: Even the smallest shunting damage often necessitates costly repairs to refrigerated trucks.
• Low range for electric vehicles: Electric vehicles with an active cooling system cannot be used on longer routes because the unit significantly reduces the range of the traction battery.

Another problem is the increased_{CO2 emissions} in food transport with actively cooled vehicles. Since the cooling technology is supplied with power via the vehicle battery, actively cooled vehicles consume significantly more fuel per kilometer traveled than uncooled vehicles. An alternative to active cooling is passive cooling in the transport of temperature-controlled food and products.

Packaging in passive refrigeration logistics

In contrast to active cooling, passive cooling works without electricity and without permanently installed units: the actively cooled hold is replaced by insulating packaging, which keeps the goods within a certain temperature range during transport. Until a few years ago, this insulating packaging was made exclusively of Styrofoam. Today, more environmentally friendly materials such as hemp and straw are also used.

In order to keep the temperature constant over longer distances , retail and logistics companies also use cold packs and/or dry ice. Passive cooling of temperature-sensitive products has the following advantages over active cooling: 

• Lower costs: Transport in non-refrigerated vehicles is significantly more cost-effective than classic refrigerated transport. A further reduction in costs is possible if companies opt for reusable solutions for insulated packaging.
• Lower risk of damage to the goods: freezer burn, which can occur in refrigerated trucks, for example, due to inadequate airflow, is not normally a problem during transport with insulated packaging.

Passive cooling in temperature-controlled transport

Passive cooling has advantages over active cooling, especially financially. In addition, companies can plan transports with passive cooling more flexibly because they are not dependent on the use of cooled vehicles. The problem: The passive cooling solutions currently available to retail and logistics companies have their limits.

The biggest disadvantage of conventional passive cooling solutions is that they only keep the goods in the required temperature range for a very limited time.

This is also the reason why passively cooled transports are normally only used for the so-called "last mile": Constant cooling for more than 36 hours is often not possible. Other disadvantages of conventional passive cooling solutions are:

• High_{CO2 emissions}: When dry ice sublimates (melts),_{CO2 is released} . This process is not only harmful to health, but also accelerates climate change (more information about the Dangers of dry ice in food transport).
• Environmental impact of packaging waste: For the passive cold chain to work, it needs appropriate packaging. Conventional disposable solutions produce tons of additional waste year after year.
• Tied to the price of dry ice: Companies that use dry ice to cover longer distances using passive cooling have difficulty scaling due to fluctuating prices.
• No uniform data tracking: Companies use solutions from different manufacturers to record temperatures and combine them with different transport containers, which makes it difficult to interpret the data accurately.

Passive cooling solutions from temprify

In view of the climate catastrophes of recent years, we no longer have to ask ourselves whether the future of refrigeration logistics is active or passive: permanently installed refrigeration units are neither sustainable nor cost-efficient. Companies that stick to active cooling will therefore not only have to calculate with ever higher energy prices in the future, but they will deliberately leave behind a massive ecological footprint.

At temprify we believe that refrigeration and freezer logistics must work without high costs and a poor environmental footprint. That's why we decided to harness the potential of passive cooling for commercial refrigeration and freezer solutions: We transform refrigeration logistics challenges into sustainable, scalable products.

As a one-stop store for passive cooling, we develop sustainable total systems that guarantee energy-efficient storage, a dry-ice-free last mile and the lowest possible cost per delivery.

Passive cooling saves money. Convince yourself!