ASHRAE Journal - February 2022 - 18

TECHNICAL FEATURE
FIGURE 3 Example of air transport insulated container with refrigeration unit.8,9
Operating Range
ULD Key Features
*
*
*
*
*
Accurate Temperature Control
* Wide Ambient Range Including Extreme Conditions
*
GDP Certified
1 Pallet or 4 EUR/5 U.S. Pallet Offering
3 Independent Refrigeration Redundancies
Full Electric with NiMH Battery for Autonomy,
100+ Hours
Fits Containers from 1.5 m3 - 4.5 m3 & 4.5 m3 - 8.5 m3
0°C to +25°C
FIGURE 4 Examples of marine intermodal refrigerated containers.8 - 10
Container Key Features
Operating Range
*
*
*
*
*
Accurate Temperature Control
* Wide Ambient Range
*
Full Electric or Diesel Option (With Generator Set)
Real-Time 24/7 Visibility
ISO Standard for Containerized Shipping
GDP Certified
Fits Multiple Size Containers (3 m, 6 m, 12 m)
-70°C to +30°C
refrigeration but could be used in combination with vaccine
packages containing dry ice or other thermal storage
to extend life.
Ship Transport Products, Also Used for On-Site Storage
Container units are systems used on ships for refrigerated
transport. Figure 4 shows examples of marine intermodal
refrigerated containers. Container size typically
ranges from 3 m to 12 m (10 ft to 40 ft) in length. ISO
standard boxes are well insulated to minimize heat load
from conduction or solar radiation. Systems operate
from electrical power input provided by the ship during
transport. When the container box is unloaded, it can
be connected to a diesel generator (genset) for portable
power during transport to the final destination.
A wide range of product technologies are available,
which could be used in the vaccine cold chain.
Conventional systems are capable of maintaining box
temperatures from -30°C to 30°C (-22°F to 86°F) in up
to 50°C (122°F) ambient, making them suitable for the
transport of many vaccines, aside from those requiring
ultralow conditions. Additional products are available
that provide storage temperatures down to -40°C
(-40°F) as well.
For ultralow refrigeration, products are available using
a dual compressor cascade refrigeration system capable
of maintaining a -70°C (-94°F) in 3 m to 6 m (10 ft to
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ASHRAE JOURNAL ashrae.o rg
F E B R U A RY 2022
20 ft) special insulated containers. Such products are
capable of direct storage of vaccines requiring ultralow
refrigeration. Special care may be required to ensure
proper temperature control and uniformity for direct
storage without supplemental thermal storage/dry ice.
As these products are typically used for long-term
transport, they are designed for optimum air distribution
and temperature control of ±0.25°C (0.45°F). Units
are down-flow, with conditioned air supplied through a
T-bar floor system in the box to attain the most uniform
temperature control possible. Systems also typically use
automatic fresh air exchange for the management of air
quality inside the container.
Systems are available with real-time telematics for
performance monitoring and security. This includes
GPS tracking, along with geofencing to monitor if the
container has moved from a designated area. Real-time
onboard data, including internal container temperature,
product temperature sensors, along with temperature
recording, can be remotely transmitted to a
data server for monitoring. Systems may also use data
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ASHRAE Journal - February 2022

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