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Overview
Ultralow temperature (ULT) freezers are designed to
operate between -86°C and -45°C, but usually op-
erated at a set point of -70°C or -80°C. ULT freezers
have a typical service life between twelve and f-
teen years. When considering the replacement of a
ULT ten years old, or older, there are many variables
to consider. New technology solves some of the is-
sues found in older freezers and reects new trends
in Ultralow Range (ULR) freezer construction.
Types of ULT freezers and
popular options
• ULT freezers come in two basic types, chest
freezers and upright freezers. Chest freezers
are more ecient than uprights, but due
to common space limitations fewer chest
freezers are purchased. Less than 5% of ULT
freezer sales are chest style. Chest freezers
last longer because the eciency of their
design requires less use of the compressor.
The same eciency also allows for
temperature set points to be reached more
quickly, and maintained.
• One popular option is the twin ULT
freezer with separate compressors. Some
manufacturers also provide a backup
compressor so if one fails, the other
maintains temperature.
• ULT freezers with vacuum insulated panel (VIP)
insulation have more capacity within a small
footprint, and so are a good option where
oor space is limited. A VIP panel is thinner
due to the lower thermal conductivity of a
partial vacuum compared to the conventional
foam insulation necessary to achieve the same
thermal insulating properties. It is important
to protect the integrity of VIP panels. Cracks
caused by temperature uctuations can
compromise the partial vacuum conditions and
degrade insulating properties. Opening and
closing the door of a VIP insulated freezer too
frequently can lead to cracks in the insulation,
causing failures.
Key Considerations
when Purchasing
Size, placement, frost, energy, and maintenance are among the
topics discussed.
