Thermal pallet cover or refrigerated truck? When passive insulation is enough
Short answer: for journeys of up to about 12 hours, transfer moments and multimodal transport, a thermal cover is in practice often sufficient, at a fraction of the cost of chilled transport. For long journeys with a strict temperature regime (such as pharma at 2 to 8 °C over several days), active cooling remains the standard. Below we explain where the line lies.
What exactly does a thermal cover do?
A thermal cover (also called a pallet cover or insulating cover) is a flexible, reflective cover that is placed over a pallet, roll container or ULD. The cover does not cool actively, but forms a passive insulation layer that keeps out heat transfer, solar radiation and moisture. The result: the temperature in the load changes much more slowly than without protection.
When is passive insulation enough?
- Short and medium journeys. In city distribution and journeys of a few hours, a well-fitting cover, especially in combination with cooling elements, keeps the load well within the margin.
- Transfer moments. The greatest temperature risk is not in the journey but in the waiting: on the dock, on the platform, in the cross-dock. That is exactly where a thermal cover protects.
- Air freight. In air freight, pallets and ULDs sometimes stand unprotected on the platform for hours in full sun or freezing cold. Thermal covers are the standard solution there, because a refrigerated truck does not drive into the aircraft.
- As a safety net alongside active cooling. Even inside a refrigerated truck, a cover adds stability during frequent door movements, and it bridges breakdowns or waiting times.
When is active cooling needed?
Choose a refrigerated truck or reefer when the load must stay within a narrow range for days, for extremely long transport times without a stop, or when laws and regulations prescribe continuous active cooling with temperature recording. Passive insulation slows temperature change, but does not stop it completely.
The cost difference
Chilled transport is more expensive per journey and more limited in availability, especially in peak periods. A reusable thermal cover is a one-off purchase that often lasts many journeys. For many shippers, the combination of standard transport + thermal cover + cooling elements is therefore a cost-effective route, without compromising product quality.
How to make the choice: five questions
- How long is the total time in transit? Include waiting times and transfers, not just the driving time.
- How narrow is the permitted temperature range? The narrower it is, the sooner active cooling is needed.
- Which season and which route? A summer route with a lot of waiting time demands more than a short winter journey.
- Is temperature recording mandatory? Check what your customer or industry requires and record that in advance.
- How often do you ship? On fixed, recurring routes, a reusable cover pays off sooner.
Comparing the costs
Do not compare only the journey price. Set side by side, per shipment: the cost of the refrigerated truck or reefer, the cost of cover and cooling elements per journey (purchase divided by the number of journeys), and the risk of damage or rejection. Ask your carrier about rates and availability in busy periods. A similar trade-off applies to containers, see reefer or container liner.
Practical rules of thumb
- Always load products at the right starting temperature; a cover holds temperature, it does not create it.
- Combine with gel packs for an extra buffer in warm weather.
- Make sure the cover fits well around the pallet or ULD, because gaps are heat leaks.
- Always cover the top, because that is where most heat enters.
- Measure your route once with a data logger; then you know for certain what happens in your supply chain.
How to test without risk
Do you want to know whether passive insulation is enough for your route? Start with a trial shipment alongside your current way of working. Place a data logger in both shipments and compare the temperature curve. Look especially at the moments of waiting and transfer. That way you base the choice on your own measurement data instead of on assumptions. How long a cover keeps the load at temperature depends on starting temperature, outside temperature, waiting time and the mass of the load. Read more about this in how long does a thermal cover keep the load at temperature.
Frequently asked questions
Is a thermal cover a replacement for a refrigerated truck?
Not in all cases. On short routes and at transfers it can be sufficient. On long routes with a strict regime, active cooling is often still needed.
Can I also use a cover in a refrigerated truck?
Yes. It can provide extra stability during door movements or waiting times.
What happens if the cooling fails?
A cover slows the warming of the load and can thus buy time. How much time depends on the circumstances.
Which loads are sensitive to warming?
You determine that yourself on the basis of your product and your customer's requirements. If you know the permitted range, you can tailor the route, the cover and the cooling elements to it. If in doubt, ask us to think along with you.
How many cooling elements do I need with a cover?
That depends on the load, route and weather. Start with a trial shipment and measure the curve, then you can adjust the quantity.
Want to test it yourself?
Take a look at our full range of thermal pallet covers in standard sizes for EURO and block pallets, roll containers and ULDs, from our own production since 1972 and delivered within a few working days. Made-to-measure solutions are possible for non-standard sizes. You can read more about the covers themselves in insulating thermal pallet cover and on our page about reusable thermal pallet covers.
