Air Curtains for Energy-Efficient Refrigerated Vans: Do Smaller Vehicles Benefit from BlueSeal?

In our previous test, we demonstrated the performance of BlueSeal air curtains in a semi-trailer cargo space, showing cooling fuel energy savings of 30-40%. These results led to the development of BlueSeal Original, which has been widely adopted in the food and pharmaceutical industries.

We later created BlueSeal Compact – a streamlined model designed for minimal obstruction in smaller cargo areas. Before launching, we wanted to test whether air curtains for energy-efficient refrigerated vans could deliver the same advantages as in larger vehicles, maintaining maximum efficiency while reducing energy loss.

Why Smaller Vehicles Need Air Curtains for Energy-Efficient Refrigerated Vans

Temperature-controlled vans face the same challenges as larger refrigerated trucks: significant cold loss occurs when cargo doors are opened. Without an effective climate barrier, cooling units must work harder, using more energy and fuel.

Testing the Design in a Refrigerated Van

We tested BlueSeal in a Mercedes Vito van (internal cargo space approx. 4.8 m³) at outside temperatures of 16-17 °C. The van’s temperature was regulated by a diesel cooling system (also electrically powered when needed).

Ten sensors were placed throughout the cargo space, recording temperatures every 5 seconds over a 6-hour period.

• Day 1 – Single 1-minute door opening, with and without BlueSeal
• Days 2 & 3 – Repeated door openings, comparing no barrier, PVC strips, and BlueSeal

(Figure 1 shows the cargo space layout; Figure 2 details the sensor locations.)

Fig 1. Cargo space of the Mercedes Vito. Locations in height are given for the 8 sensors near the rear doors and in the centre of the cargo space

Test 1 – Single Exposure: Cargo Air Temperature

The centre of the cargo space proved most vulnerable to heat gain. Without any barrier, temperatures near the ceiling rose 17 °C within one minute. With air curtains for energy-efficient refrigerated vans, this increase was limited to 7.5 °C.

As Figure 2 shows, temperatures rose significantly less across almost all sensors when using BlueSeal, except at floor-level near the cargo door – likely due to the air curtain’s downward turbulence.

Test 2 – Repeated Door Openings

Over four consecutive 1-minute door openings:

• No barrier – Temperatures at 75 cm and 95 cm height in the centre rose 15-18 °C (Figure 3a)
• With BlueSeal – Only 7-8 °C increase

Without a barrier, temperatures near the floor rose less, likely because the ceiling, walls, and floor helped cool incoming air. However, cooling units had to work much harder to restore temperatures, increasing energy use.

With air curtains for energy-efficient refrigerated vans, energy use was reduced and cargo temperatures stayed more stable, even after multiple openings.

Test 3 – BlueSeal vs PVC Curtains

We compared BlueSeal with PVC strips, the traditional climate barrier. During 3-minute door openings:

• PVC strips – Air temperatures rose 20-22 °C near the ceiling and cargo centre
• BlueSeal – Rise limited to 17 °C

PVC strips often allow upper-level warm air infiltration, while BlueSeal maintained more consistent ceiling-to-floor temperatures thanks to its controlled circulation pattern.

Conclusions: The Case for Air Curtains in Energy-Efficient Refrigerated Vans

BlueSeal performed excellently as a climate control method in small cargo spaces. Whether in single or repeated door opening scenarios, BlueSeal significantly slowed temperature rise and reduced the cooling unit’s workload.

Compared with PVC curtains, air curtains for energy-efficient refrigerated vans provided better temperature stability, improved hygiene (no physical barrier to push aside), and reduced energy costs.

These 2013 tests laid the foundation for BlueSeal’s development into a fully commercial product, now used globally by operators seeking better cold chain management. Subsequent independent studies have confirmed these benefits, cementing BlueSeal’s place as a leading solution in refrigerated vehicle climate control.