Navigating Cold
Storage Solutions
A practical guide to help choose the right
refrigerators and freezers for your needs
PHC Corporation, Biomedical Division PHCNA Marketing Material
Contents
Key factors contributing to TCO 25
Selecting cold storage units with optimal uniformity and recovery 10
Key considerations for sustainability 32
The CDC vaccine storage guidelines 15
Assessing reliability and robustness 19
ULTs: liquid nitrogen (LN2) vs mechanical 36
Storage capacity 7
Features to look out for 28
Understanding the impact of testing variation 11
The NSF 456 regulations 17
A key feature to look out for 23
Integration with existing systems 39
Advancements in cold storage technology 40
Calculating total cost of ownership 30
Features to look out for 12
2. Capacity, Space, and Location 5
6. Total cost of ownership (TCO) 24
3. Temperature Uniformity and Recovery 9
7. Sustainability 31
9. Feature recommendations summary 41
10.Choosing the ideal cold storage solution for your needs 43
4. Regulatory requirements (for traditional vaccine storage) 13
5. Reliability and robustness 18
8. Technological considerations 35
1. Introduction 3
Available floor space 6
2 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Introduction
01
3 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Refrigerators, freezers, and ultra-low
temperature (ULT) freezers play a vital, but often
underappreciated, role in science, safeguarding
precious samples and materials while ensuring
scientific progress goes on unencumbered.
With recent advancements in medical treatments,
the demand for cold storage units has surged.
The development of mRNA vaccines during the
COVID-19 pandemic, which requires storage at
temperatures ranging from -80o
C to -15o
C,1,2 has
increased demand for ULTs by more than 500%
according to some accounts.3
The growth of
cell and gene therapies has further driven the
need for cold storage solutions.4
As we continue
to develop more novel, advanced therapies
and vaccines, purchasing reliable, high-quality
performance refrigerators and freezers will
become ever more important for maintaining
scientific progress.
Selecting the right cold storage solution,
however, is challenging.
With so many different options, performance
metrics, regulations, and features to consider,
choosing a reliable cold storage unit that fits your
needs can feel overwhelming. It’s no surprise,
then, that people might struggle to make a
confident purchasing decision. Indeed, without
knowing what to look for, decision makers
risk buying a less than adequate refrigerator
or freezer, wasting time and resources and, at
worst, hampering any further research progress
or compromising valuable products and samples.
This eBook provides practical, expert advice to help you more confidently
purchase an optimal cold storage unit for your needs. By reading it, you’ll
learn more about:
Key metrics to evaluate performance and how to interpret them
Regulatory considerations to keep in mind for vaccine storage
Sustainability considerations
How to help maximize the chances of a long-term cost-effective purchase
Key technological factors to look for
$
4 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Capacity, Space,
and Location
02
5 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Available floor space
The floor space you have available in your
facility will be a big deciding factor when
it comes to the most suitable style of
refrigerator or freezer — upright models
or chest models.
Upright models tend to have a smaller
footprint,5
so they can be ideal for making
the best use of limited space. They are
also ideal for storing materials that require
frequent access. Chest models, on the other
hand, typically have a larger footprint6
(and
so may not be suitable for space-strapped
facilities), and are better suited for the longterm storage of materials that don’t need to
be accessed as often. They also reduce the
range of temperature fluctuation between
door openings as more cold air remains in
the chamber compared to upright models
that have the cold air leaving the chamber
after each door opening.7
In addition to the unit’s physical size, you also
need to keep in mind ventilation clearance
requirements when deciding on the best-fit
unit for your floorspace; most refrigerators
and freezers will require at least six inches of
clearance to the sides and rear of the unit
to allow the heat from the compressor to
properly ventilate, and for easy access in case
repair technicians need to access other parts
of the unit.
One of the first things to consider when looking for a new cold storage
solution is the size and capacity that will best fit your current and projected
research needs, and the size limitations of your facility.
6 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Storage capacity
Another important initial consideration is the quantity of
material that you’ll need to store. High-volume capacity
units are necessary for facilities with large-scale or long-term
storage needs. For labs with fewer or more specialized storage
needs, smaller volume units will generally suffice.
Unit capacity is often measured either by cubic foot capacity,
or by how many standard 2-inch sample boxes they can hold.
Careful consideration of these metrics helps ensure you select
a solution that balances volume with practical usability for
your specific needs.
For help with deciding on the best storage solution for your
capacity and space needs, you can use the following decision
tree:
7 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
What is the required storage volume for your samples?
High capacity for large volumes Go to 2
1 Moderate to low capacity for smaller volumes Go to 3
How much physical oor space is available in your lab or facility?
Ample space for larger units Consider Chest Models
(high-capacity storage but requires more oor space, ideal for bulk storage with less frequent access).
Limited space available Consider Large Upright Units
(upright models with high storage density, designed to optimize space in compact areas).
2
Are you primarily storing smaller samples that bene t from organization?
Yes, need to organize smaller samples Consider Upright Models with Racking Options
(allows high-density, organized storage of smaller samples in a small footprint).
No, bulk storage is needed for larger samples Consider Standard Chest Models
(more space-ef cient for larger samples, where organization is less critical).
5
Will the cold storage unit be placed in a controlled or restricted area, like a cleanroom?
Yes, in a cleanroom or controlled space Look for Cleanroom-Classi ed Upright Units
with compact pro les and low particle emissions (ISO-rated units suitable for restricted spaces).8
3
No, in a standard lab or room Go to 4
Do you need easy access to samples with limited oor space?
Yes, frequent access in limited space Consider Slim-Pro le Upright Models
(small footprint and convenient access in tight spaces). 4
No, occasional access is ne Go to 5
8 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Temperature Uniformity
and Recovery
03
9 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
The most important function of a cold storage unit
is to maintain the temperature of stored materials.
To do this reliably, refrigerators and freezers must
have good temperature uniformity and recovery.
But what do these measures actually mean?
Temperature uniformity refers to the
consistency in temperature across different points
within the unit’s chamber. In cold storage units,
every part of the chamber should maintain the
same temperature to ensure all stored materials
are kept in the same optimal conditions.
Temperature recovery is simply how quickly the
unit can return to the set temperature after the
door is opened (exposing the chamber to warm
air) and then closed. A high-quality unit should
have sufficient cooling capacity to quickly return
the contents to the set temperature.
Without good temperature uniformity and
recovery, a cold storage unit could end up
compromising the integrity of stored materials,
impacting their quality and viability.
Selecting cold storage
units with optimal
uniformity and recovery
Unfortunately, there is no ‘one-size-fits all’
value to look for when it comes to assessing
uniformity and recovery metrics. Generally
speaking, prospective buyers should look for
units that return to temperature as quickly as
possible after door opening and that don’t
give rise to hot or cold spots in the chamber.
Ultimately, though, the most important thing is
to consider the needs and requirements of your
specific application and select equipment that
can adequately meet those needs. For instance,
storing vaccines requires strict adherence to
very specific storage temperatures (discussed in
more detail in Chapter 4).
10 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Understanding the impact of testing variation
To make sure a unit meets your specific temperature
recovery and uniformity requirements, you’ll need
to understand and be able to interpret performance
testing data. To do that, you’ll need to understand
variations in common testing conditions and how
they can impact performance readouts.
Probe placement
Probe placement during testing can vary between
cold storage equipment providers and can impact
both temperature recovery and uniformity readouts.
When it comes to measuring uniformity, the
number and location of probes can range from
just one probe in the center of the unit, to multiple
probes scattered evenly throughout. Fewer probes,
or poorly positioned ones, can underestimate
temperature fluctuations within the unit.
When evaluating temperature recovery, it is
important to be aware that probes placed near
the back, lower parts of a ULT chamber (away
from the door and in close proximity to cooling
systems) will read a faster temperature recovery
than those at the top or front (positioned closest
to the door and furthest from cooling systems).
Similarly, for refrigerators, probes placed near the
air-cooling outlet will recover more quickly than
those elsewhere.
Unit contents
How full a unit is can also impact temperature
recovery. Since most of the energy expended by
a refrigerator or freezer goes into cooling down
the warm air that enters upon door opening,
the more a unit is filled (and thus the less air
space there is in the chamber), the faster the
refrigerator or freezer can recover.
Ambient temperature
The temperature of the testing area can impact
temperature recovery readouts. When a unit is
tested in higher ambient temperature conditions,
there will be a larger temperature difference
between the chamber and the air surrounding
the unit, leading to a larger drop in temperature
upon door opening, and thus a slower recovery
following door closure (relative to the same unit
tested at a lower ambient temperature).
Top Tip
To get a clearer idea of just how relevant
manufacturer testing results might be for
your application, ask yourself if the testing
conditions reflect your anticipated usage
of the equipment. Are probes placed in
the areas where you will store samples
or products? Are door opening durations
realistic for your use case? If not, ask the
equipment provider if they can conduct
unit testing according to your requirements.
11 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Features to look out for
Beyond just looking at uniformity and recovery performance readouts, consider looking for units with the
following features, which can help to ensure consistent chamber temperatures.
Traceability Remote temperature monitoring systems
Units with access tracing capabilities,
such as those afforded by electronic
digital locks, key cards, or facial
recognition, can help teams spot
deviations from best practices (such as
prolonged door openings) and swiftly
address them. Traceability can therefore
be a useful tool in helping reduce
temperature excursions and protecting
valuable stored products and samples.
Look for units that can easily integrate with remote
temperature monitoring systems. These systems allow
organizations to track temperature in real time and can
send instant alerts when temperatures fall outside of the
appropriate range. This can help teams quickly identify
and address temperature excursions to better protect
the integrity of the unit’s contents. Remote temperature
monitoring systems tend to use Wi-Fi or Ethernet
connectivity, however, there are other emerging methods
of connectivity such as Bluetooth, cellular, etc.
12 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Regulatory requirements
(for traditional vaccine storage)
04
13 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
If you are looking to purchase refrigerators or freezers to
store traditional vaccines, there are additional regulatory
requirements to consider.
Proper vaccine storage is vital in preventing and eradicating
vaccine-preventable diseases; improper storage can reduce
vaccine potency, resulting in inadequate immune response
in patients. Poor vaccine storage can also lead to significant
financial losses if vaccines are no longer usable, or if
revaccinations are necessary.
Two guidelines help assure the adequate storage of vaccines
— the CDC guidelines9
and the NSF 456 guidelines10 — with
implications for your choice of refrigerator or freezer.
14 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
The CDC vaccine storage guidelines
The CDC recommends using purpose-built
(otherwise known as pharmaceutical-grade) units
that are specifically designed for the storing of
biologics (including vaccines).9
Such units come
in a range of sizes, and often have features
such as microprocessor-based temperature
control and fan-forced air circulation to promote
good temperature uniformity and recovery,
ensuring stored vaccines are kept within the safe
temperature ranges.9
Refrigerators: 36oF – 46oF (2oC – 8oC)
Freezers: -58°F – +5°F (-50°C – -15°C)
ULT freezers: -130°F – -76°F (-90°C – -60°C)
Temperature requirements Refrigerator and freezer recommendations
15 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
The CDC also stresses the importance of regular
maintenance (which is generally recommended,
whatever your refrigerator or freezer application).9
Looking for a unit that is easier to maintain
and has features that reduce maintenance
requirements, such as frost-reduction (discussed
in more depth in chapter 6), could help
reduce the time and costs associated with such
maintenance.
The CDC guidelines also state that every cold
storage unit for vaccines must also have a
temperature monitoring device that can maintain
an accurate temperature history.9
An accurate
temperature history is critical for protecting
vaccines, as it can help organizations identify
whether vaccines have been stored at out-ofrange temperatures at any point in their lifespan.9
Specifically, the CDC recommends a type
of temperature monitoring device called a
digital data logger (DDL), which provides
the most accurate storage unit temperature
information.9
Unlike a simple minimum/maximum
thermometer, which only shows the coldest and
warmest temperatures reached in a unit, a DDL
provides detailed information on all temperatures
recorded at preset intervals, as well as details on
how long a unit has been operating outside of its
recommended temperature.9
For the full CDC recommendations regarding
DDLs, see the CDC vaccine storage and
handling tool kit.
Temperature monitoring device (TMD) recommendations Maintenance
16 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
The NSF 456 regulations
While the CDC provides broad recommendations, the NSF 456 standard defines specific
performance-based criteria that cold storage units must meet.
Units have to be tested according to defined procedures and under strict conditions at
accredited third-party testing organizations. Testing comprises three rigorous tests using
vaccine simulation devices (VSDs):11
An NSF 456 certified unit will have passed all of the above tests, ensuring it can maintain
the conditions necessary for safe traditional vaccine storage.
Closed-door test: with the unit door closed, all VSDs must stay within
the allowed temperature range.
Short door opening test: the door is opened once every ten minutes
over a period of three hours. The door is then opened once every five
minutes for the next hour. During the total four-hour period, the VSDs
must all stay in the allowed temperature range.
Long door opening test: after the short door opening test, the door
is opened for three minutes. Once the door is closed, all the probes
within the cabinet must recover to below 8o
C for refrigerators, or
below -15o
C for freezers, within 15 minutes.
1
2
3
17 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Reliability and robustness
05
18 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Assessing reliability and robustness
There are no specific standardized tests for reliability and robustness, making it hard to dependably
assess these aspects of performance. However, there are several ways prospective buyers can build
up a relatively good picture of a unit’s reliability and robustness before purchasing.
People within your own organization can be a valuable source of
information. For example, colleagues may have already used, or
be currently using, a unit that you are considering for purchase,
and therefore may be able to offer helpful insights about their
reliability or robustness (as well as other aspects of performance).
Repair technicians within your organization may also have
valuable insights to share. Having potentially repaired many pieces
of lab equipment in their careers, they may, for instance, be able
to inform you of common issues they have faced with particular
brands or units, or confirm if, in their experience, certain brands
experience more frequent failures.
Talking to colleagues
To adequately protect its
valuable contents, a refrigerator
or freezer must be reliable and
robust.
While reliability refers to the
predicted amount of time a
piece of equipment will perform
its expected function(s) under
stated conditions without failure,
robustness refers to how well a
product can accommodate longterm improper use or stressful
environmental conditions and
still work as new.
These qualities are vital not
only for safeguarding samples
and products but also for
reducing disruptions and costs,
since a reliable and robust unit
will require fewer repairs and
maintenance.
19 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Public and professional online forums can
be a useful source of information about the
reliability and robustness of cold storage
equipment. Reading through the relevant
discussions on forums such as r/labrats
on Reddit, for example, can give you an
overview of the community consensus and
opinion on the product and highlight any
common issues or red flags.
That said, it is important to keep in mind
that information on forums — particularly
public forums — may not always be reliable,
so remain diligent when using these as
an information source. If possible, seek
forums that do not allow employees of cold
storage equipment vendors to participate in
discussions, such as LabOps Unite.
How long an equipment provider
has been in the industry can also be
an important indicator of the quality
of the equipment they produce.
Companies who have spent longer
in the industry will have learned
valuable lessons about design and
build quality that they can leverage
to create more reliable and robust
products. Furthermore, the longevity
of a company can provide reassurance
that they are good at what they do —
while it may be easy to build a
cold storage solution, building a
good one that lasts is a difficult
task that requires extensive industry
experience.
Social media forums Assessing the experience of the equipment provider
20 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Asking the vendor the right questions
The testing process: how long do you
operate the refrigerator/freezer to assess
robustness and reliability?
A shorter testing duration isn’t likely to give you a very good
insight into long-term reliability and robustness. Ideally, look
for a provider that runs their cold storage equipment nonstop for at least six months before they take it apart and
examine component wear and tear.
Asking the vendor the right questions can also help you gather important
information that can further build out your understanding of the unit’s reliability
and robustness. We recommend asking vendors the following:
Critical components: what is the failure
rate of critical components?
Key components to inquire about include compressors,
door hinges (as they are a common point of breakage),
and display controls, focusing on issues such as screen
freezing or blackouts.
01
02
21 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Manufacturer repairs: what are the
most common repairs that need to be
made to a unit?
Manufacturer repair records can provide valuable insights
into how frequently equipment fails, and the most common
points of failure.
Third-party analysis: has the reliability/
robustness been audited by an
independent third party?
Assessment by an independent third party can provide
further confidence in a unit’s performance and verify that
information provided by the manufacturer is accurate.
03
04
22 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
A key feature to look
out for: Dual cooling
systems (ULTs)
Having two independent cooling systems provides
an extra layer of protection for valuable samples
and products. In units with this feature, there
are two independent refrigeration systems that
provide a reliable -86o
C temperature. In the event
of an unexpected failure of one cooling circuit, the
other can maintain the freezer in the -70o
C range
for a period of time until service can be arranged.
23 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Total cost of ownership (TCO)
06
24 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Key factors contributing to TCO
An often-overlooked aspect of the overall cost of a unit is the price of the floor space
it occupies in the lab. Keep in mind that the cost per sq. ft can vary significantly
depending on your location, so it is essential to keep this in mind when exploring cold
storage unit options.
When purchasing cold storage solutions, it is
important to look beyond the initial cost and
consider the additional associated costs that
can mount up over the product’s lifespan —
in other words, it is important to consider
the unit’s total cost of ownership (TCO).
There are numerous factors that can impact
a refrigerator’s or freezer’s TCO, and failure
to consider them at the buying stage can
mean that a seemingly cost-effective unit can
become a financial burden in the long run.
Floor space requirements
25 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Another contributor to overall costs is energy
efficiency. More energy efficient systems will
naturally consume less power for the same activity,
directly reducing operating costs. Over time, these
energy cost savings may offset the higher initial
purchase price, making energy-efficient models
potentially more cost-effective in the long run.12
A good way to determine a unit’s energy
efficiency is by using official ENERGY STAR®
ratings, which can be verified by the presence
of the ENERGY STAR logo. Since ENERGY STAR
testing is standardized, these ratings allow easier
comparison across manufacturers and models, too.
To make sure you can better evaluate a product’s
energy efficiency in the context of your own
application, it is important to also understand how
testing conditions affect energy consumption.
There are two important variables that impact
energy efficiency readouts (and if testing isn’t
done by ENERGY STAR, these factors may not be
the same from unit to unit).
Accessory usage
Accessory usage during energy-efficiency testing
can, understandably, impact energy consumption
results. Testing with accessories switched off, for
instance, will result in lower energy consumption
than testing with accessories on. Therefore,
it’s important that all accessories are turned
on during testing for the most accurate energy
consumption results.
Ambient temperature
Ambient temperature not only affects temperature
uniformity and recovery (as noted earlier), but
also impacts energy consumption. The ambient
temperature determines how hard a unit has
to work to maintain its low internal chamber
temperature - the higher the ambient temperature
during testing, the more energy a unit will
consume to maintain its chamber temperature.13
Energy efficiency
26 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Purchasing a reliable unit is essential for reducing TCO, as unreliable equipment can
significantly increase operational costs over time.
For unreliable units, the cost of repairs and replacement of key components can
quickly accumulate. The downtime resulting from repairs and breakdowns can also
decrease productivity and potentially result in the loss of samples or materials, further
driving up costs.
See chapter 5 for tips on how to vet a unit for reliability before purchasing.
Regular maintenance is crucial for extending the life of cold storage units,
preventing costly breakdowns, and minimizing downtime. By purchasing units
that require less maintenance, or are easier to maintain, businesses can reduce the
associated expenses.
Reliability
Maintenance
27 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Features to look for
When choosing cold storage equipment, certain features can help lower
the TCO:
Frost reduction (ULTs)
Frost build-up can damage freezer components, put pressure on
the freezer outer door, and reduce energy-efficiency. Clearing the
frost buildup is therefore an essential but time-consuming part of
maintenance.
A ULT that reduces the accumulation of frost decreases maintenance
time, freeing up staff for more valuable activities and improving
productivity. Additionally, less frost accumulation ensures that the freezer
is functioning optimally, helping maintain energy efficiency and reduce
the frequency of repairs (further lowering costs).
28 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Warranties
Outside of performance considerations, the type of
warranty that accompanies a cold storage unit can
have a significant impact on TCO. To reduce overall
costs, decision makers should look for a parts and labor
warranty, as opposed to a parts-only warranty.
While a parts-only warranty means you won’t need
to buy parts for repair (which are often only a small
fraction of the total cost of repair), you’ll still need to
arrange, manage, and pay for labor, which can be very
expensive and time-consuming.
A full parts and labor warranty, however, covers parts
and labor expenses, and will also mean you don’t need
to arrange the repair work, making it a more costeffective and less time-consuming option in the long run.
29 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Calculating total
cost of ownership
With so many factors to consider when
it comes to TCO, it can be helpful to create
a cost table that tracks and compares the
key factors across different units. On the
right is a blank template of such a table.
Unit 1 Unit 2
Annual floor space cost
Unit footprint (sq.ft) x annual floor space cost (e.g.,
$/sq.ft)
Annual unit energy cost
Energy consumed (kWh/day) x 365 x
local energy cost (cents/kWh) x 100
Estimated annual unit maintenance
cost (labor and parts)
Annual unit LN2 cost (relevant if
purchasing an LN2 ULT unit)
LN2 tank rental cost + LN2 cost + LN2 delivery cost
Annual operational cost
Annual floor space cost + annual unit energy cost +
annual unit maintenance cost + annual LN2 cost
Predicted length of ownership (years)
Lifetime operational cost
Annual operational cost x predicted length of
ownership
Initial unit purchase cost
Total cost of ownership
Lifetime operational cost + initial purchase cost
30 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Sustainability
07
31 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Key considerations for sustainability
Please note that the information below applies exclusively to US markets.
Units with greater energy efficiency consume less energy to achieve their required functions
and are thus more environmentally friendly. Look for official ENERGY STAR certification, as
this provides assurance that a unit meets stringent energy efficiency criteria.
Be aware, however, that the requirements for ENERGY STAR certification are changing
after June 30th, 2025. Due to advances in cold storage efficiency, the baseline for efficient
energy consumption will be reduced, meaning >80% of the products that currently have
an ENERGY STAR certification may lose it after June 2025. As such, check with vendors
that the product in question will still be part of ENERGY STAR after the changes (as this will
ensure you purchase a product that continues to be among the most energy efficient on
the market).
Reducing environmental impact is becoming an increasingly important
focus in the life sciences sector. Cold storage equipment can be a significant
contributor to an organization’s environmental impact, so it’s important to
select the most sustainable option that fits your application.
Energy efficiency
32 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Different refrigerants have drastically different environmental impacts.
To determine the level of impact of the refrigerants used in a cold storage unit,
purchasers can look at their Global Warming Potential (GWP) by doing a simple
internet search. GWP is a measure of the relative impact of different greenhouse gases
on global warming compared to carbon dioxide, which is assigned a value of 1. For
instance, a refrigerant with a value of 12 would be 12 times more polluting than CO2.
One of the most popular refrigerants used today, R-134a, has a GWP of 1,430.
However, newer, natural refrigerants that are much more environmentally friendly are
now available. Hydrocarbon refrigerants such as isobutane (R600A) and isopropane
(R290), which have GWP scores of 3, for example, are becoming increasingly popular
as an alternative to higher GWP refrigerants.14
As well as being better for the environment15, natural hydrocarbon refrigerants are
also more energy efficient, resulting in lower running costs.
Looking for manufacturers that are committed to continuing supply of parts after
the end of production will mean organizations can use their unit for longer before
buying a replacement, reducing the number of units going to waste, and saving costs
associated with more frequent unit replacements.
Natural refrigerants
Product support
33 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Cold storage units can still have a significant
environmental impact even at the end of their
life, particularly if they go to landfill. As such,
when purchasing a cold storage unit, look for
companies that offer take back programs for
old products, and be sure to confirm what they
do with the units once they receive them. If
they simply send the old units to landfill, then
the take-back program does little to mitigate
environmental impact.
Some companies also offer programs whereby
old equipment can be donated to developing
countries, helping to both minimize e-wastage
in landfill, and giving organizations a unique
opportunity to access critical equipment they
might otherwise struggle to purchase.
Equipment end-of-life
considerations
34 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Technological considerations
08
35 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
ULTs: liquid nitrogen
(LN2) vs mechanical
When selecting ULTs, two primary cooling
technologies are available: liquid nitrogen
(LN2) systems and mechanical refrigeration.
Understanding the advantages and
limitations of each is critical for selecting a
unit that best meets your needs.
In addition to the wealth of features
discussed throughout this eBook, there
are several other important technological
considerations to be aware of when
purchasing cold storage equipment.
36 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Liquid nitrogen systems
In LN2 freezers, liquid nitrogen is stored in highly
insulated containers and achieves extremely
low temperatures through vapor expansion
(transitioning from liquid to gas).
Mechanical ULT freezers
These systems employ multiple refrigeration
cycles using a blend of refrigerants to reach ultralow temperatures. High-insulation materials, such
as blown-in foam and vacuum insulation panels
(VIP), help maintain temperature consistency.
How the two technologies work
Lower operational costs
Mechanical freezers have much lower
operational costs than LN2 freezers, with
LN2 freezers having continuous costs
associated with the procurement, delivery
and handling of LN2.
16 By far the largest
cost is that of the LN2 itself, though — on
average an LN2 freezer consumes up to
$9000 worth of LN2 a year.16
By comparison, mechanical freezers
consume only electricity, the cost of which
amounts to only around $700 a year.16
Safety considerations
Handling and storing LN2 poses risks
including: asphyxiation, frostbite from
accidental exposure, and potential
container explosions (if not properly
vented). Mechanical freezers reduce these
risks by relying solely on electrical power,
enabling safer operation.
Environmental impact
Producing liquid nitrogen is energyintensive, involving high-pressure
liquefaction of atmospheric air. With
the process being only 25% efficient,
a significant portion of nitrogen is
also wasted during production.16 This
inefficiency contributes to a higher
environmental footprint compared to
the mechanical freezers, which rely
only on electricity.16
Advantages of mechanical ULT freezers over LN2
37 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Despite their limitations, LN2 freezers may be
preferable for applications that demand rapid
cooldown rates, or when maintaining extremely
low, stable temperatures over extended periods
is critical. Their simplicity and independence
from electrical grids also make them valuable
in areas where a stable power supply can’t be
guaranteed.
Choosing between LN2 and mechanical ULT
freezers ultimately depends on your operational
priorities, cost considerations, and safety
requirements. Assessing these factors will help
ensure that the cryogenic storage solution you
select is right for your needs.
When to consider LN2 freezers
38 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Integration with existing systems
Ensuring a new refrigerator or freezer integrates seamlessly with
current systems is critical for efficient operations and reliable data
management. There are several key features to look out for to help
increase chances of a smooth integration.
Ensure that new ULT freezers have rack systems compatible with
current cold storage equipment. This compatibility is crucial for
maintaining efficient workflow and optimizing storage capacity.
Additionally, having interchangeable racks and similar capacity to
current cold storage units allows for easy sample transfer between
units during preventative maintenance or repairs, minimizing
downtime and protecting sample integrity.
Rack compatibility and capacity (ULTs)
39 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
For facilities located in remote areas or regions prone to signal
interference, hardwired connections are more reliable than
wireless connections. Choosing a unit with options for hardwired
connections can therefore lead to a more reliable integration with
other lab equipment.
New storage units should be able to seamlessly integrate with
common facility alert systems, enabling real-time notifications of
temperature fluctuations or system issues. This integration is crucial
for timely identification of — and response to — issues, and thus
for maintaining sample and product safety.
Hardwired connectivity options
Connectivity to alert and notification systems
Advancements in cold
storage technology
Cold storage technology is continually improving. One notable
advancement comes in the form of inverter compressors. Unlike old
‘on-off’ compressors, inverter compressors dynamically and rapidly
adjust their speed based on the immediate cooling requirements,
helping to reduce energy consumption and enabling better temperature
uniformity and recovery after door opening.
40 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Feature
recommendations
summary
09
41 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Feature Description Benefits
Access-tracking capabilities Systems that track access, such as with digital locks, key cards, or facial
recognition, to monitor usage and identify deviations in best practices
Helps organizations swiftly address issues (such as prolonged door
openings) to minimize temperature fluctuations
Dual cooling systems (ULTs)
ULT freezers with two independent cooling circuits that help maintain
reliable temperatures. If one circuit fails, the other can keep the chamber
in the -70°C range
Provides an extra layer of protection for valuable samples and helps ensure
uninterrupted temperature control until maintenance can be arranged
Frost reduction (ULTs) Minimizes frost accumulation within the freezer Reduces maintenance time, ensures optimal energy efficiency and helps
prevent damage to components, leading to potential cost savings
Monitoring system connectivity Enables easy integration with remote systems that track temperatures in
real time and send alerts for immediate issue resolution
Helps maintain consistent temperature control, reduces energy
consumption, and ensures sample and product safety by preventing
potential temperature excursions
Inverter compressors Compressors that quickly and dynamically adjust their speed based on
immediate cooling requirements
Faster response to temperature fluctuations (leading to faster recovery),
and more efficient energy usage (compared to “on-off” compressors)
Hardwired connectivity options Enables wired connectivity to other systems and equipment Ensures secure and reliable connectivity in facilities in remote areas or
where signal interference is common
Throughout the eBook, we have recommended looking for cold storage units with various features.
We’ve summarized these features and their benefits in the table below for easy reference:
42 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Choosing the ideal
cold storage solution
for your needs
10
43 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
Refrigerators and freezers, while often overlooked, play an integral
role in the life sciences industry, safeguarding valuable samples and
products to facilitate scientific progress and improve lives. Selecting
the right refrigerator or freezer for your needs is therefore crucial.
But that’s easier said than done.
Organizations looking to purchase a refrigerator or freezer will need
to consider a wealth of factors and features to find an option that’s
right for their needs, which can quickly become overwhelming.
However, having absorbed the information and top tips summarized
in this guide, and by making use of the questions and tools, you’ll
be in a much better position to understand what to look for,
where to look for it, and how to engage with vendors to find
a cold storage solution that meets your specific application and
sustainability goals in the most cost-effective way.
Driven by a commitment to protect science, we deliver
laboratory refrigerators and freezers known for their
reliability, durability, performance, and sustainability.
Our user-centric designs and advanced features also
ensure operational ease and effortless use.
Backed by a rich cultural heritage of excellence, our
cold storage equipment empowers labs worldwide to
deliver seamless scientific progress with confidence.
Browse our broad selection of cold storage solutions
today, or reach out to one of our knowledgeable team
members to discuss how our solutions can meet your
specific cold storage needs.
Product pages
Contact us
44 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
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10. National Sanitation Foundation International. NSF/ANSI 456: Vaccine Storage Standard. 2021. https://webstore.ansi.org/standards/nsf/nsfansi4562021a?srsltid=AfmBOor1xNPFr_0NuI_CAO3dk2ASK0-XknbLpbrTGkYzn08yAG7N8zgN. Accessed January 10, 2025.
11. Thermo Fisher Scientific. Vaccine Storage Standards by NSF International Whitepaper. https://assets.thermofisher.com/TFS-Assets/LPD/Technical-Notes/Vaccine%20Storage%20Standards%20by%20NSF%20International%20Whitepaper.pdfAccessed January 10, 2025.
12. Practice Greenhealth. Mayo Clinic: Replacing Freezers Leads to Energy and Cost Savings. Practice Greenhealth. https://practicegreenhealth.org/tools-and-resources/mayo-clinic-replacing-freezers-leads-energy-and-cost-savings Accessed January 10, 2025.
13. Gumapas LAM, Simons G. Factors affecting the performance, energy consumption, and carbon footprint for ultra-low temperature freezers: case study at the National Institutes of Health. World Rev Sci Technol Sust Dev. 2013;10 (1/2/3):129.
14. American Biotech Supply. Environmentally Friendly Refrigerants. https://americanbiotechsupply.com/environmentally-friendly-refrigerants/. Accessed January 20, 2025.
15. Hwang Y, Jin DH, Radermacher R. ARI: Global refrigerant environmental evaluation network (GREEN) program comparison of hydrocarbon R-290 and two HFC blends R-404A and R-410A for medium temperature refrigeration applications. Final interim report. Air-Conditioning,
Heating, and Refrigeration Institute; March 2004. https://www.ahrinet.org/system/files/2023-06/Green%20Program%20Report%20Final-03-04_0.pdf Accessed January 10, 2025.
16. PHC Corporation of North America. The Future of Cryogenic Storage: A Comparative Analysis Between Liquid Nitrogen and Mechanical Freezers. 2024. https://pages.services/markitbiomedical.com/energy-use-in-cryogenic-storage-white-paper/?utm_source=linkedin&utm_
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45 NAVIGATING COLD STORAGE SOLUTIONS: A PRACTICAL GUIDE TO HELP CHOOSE THE RIGHT REFRIGERATORS AND FREEZERS FOR YOUR NEEDS
