Do you store temperature sensitive items correctly?
A fridge isn't just a fridge
Debates about throwing away medicines, essentially money, due to improper storage conditions - is ever-present. We argue that debates of this nature are relevant, but we strongly believe that the solution is simple and straight forward. Here is why
Household refrigerators should not be considered for professional use especially when it involves storing temperature sensitive material. The common misconception is that one refrigerator is as good as another, it’s not that difficult to have a stable and uniform temperature, right?
You would be surprised…
In an industry where large amounts of expensive materials are stored, it is a relevant question to ask if a refrigerator intended for storing food - is suited for storage of medicine?
Temperature in the cabinet
There is never only one temperature in a cabinet. Temperature varies in a cabinet depending on where you are measuring. The temperature difference depends on the surroundings, degree of use and how the refrigeration system is constructed. Best possible temperature uniformity in a cabinet is achieved by having forced air distribution in the cabinet, that distributes the cold evenly and minimises hot/cold spots.
What should you look for?
Many considerations have to be made when assessing what a refrigerator or freezer for the life sciences should be capable of and feature.
Inadequate refrigerators and freezers often pose as some of the weaker links in the cold chain.
Here are some pointers as to where to focus, thereby keeping risks low and item quality high.
No cold walls
A refrigeration system that is not located in the storage space, does away with cold walls, allowing for better and safer use of the storage space
Forced air distribution in the cabinet distributes air around the cabinet and ensures high temperature stability and uniformity
Designed for professional use ensures reliability, capacity and long life
Acoustic and visual alarms
Gives clear indication if temperature limits have been exceeded, providing additional security for the stored items
Customise to specific requirements. Allowing good utilisation of the storage space, improved ergonomics and high security of the stored items
Offers easy viewing allowing shortest possible door opening time
No cold walls, no frost damage, better utilisation of storage space
The elimination of cold walls is achieved with a ground-up approach, and results in many advantages
No cold walls!
The term “cold walls” and frost damage in a refrigerator is a common occurrence and a challenge when dealing with storage of temperature sensitive materials such as medicines.
Temperature-stability and uniformity
Professional design differing considerably from household and commercial refrigerators eliminates cold wall loss of items by frost exposure even when placed against the the back wall.
Using a finned tube evaporator and placing it away from the storage chamber eliminates cold walls. A fan forces cooled air around the cabinet to ensure even distribution.
Utilisation of storage space
As there is no need to take cold walls into consideration, the entire storage space can be used for storage, ensuring maximum ultilisation of the cabinet.
A conventional refrigerator
A Conventional refrigerator with the evaporator down the back of the storage space.
The main implication of having the evaporator down the back of the storage chamber is very localised generation of cold, often resulting in sub-zero temperatures in many places.
With this extensive emission of cold at the back of the storage chamber, it is very difficult to control which parts of the storage chamber are and aren't exposed to this intensive cold.
Ultimately you are forced to remove items from the back of the cabinet to prevent frost damage, essentially making 15-25% of the storage chamber useless. Additionally, temperature stability and uniformity is greatly impeded as it is difficult to control where and how the cold is distributed throughout.
A refrigerator with a finned tube evaporator
A BioCompact II 210 refrigerator with a finned tube evaporator.
A construction with a finned tube evaporator has many advantages. The first distinguishing factor is that the evaporator is removed from the storage space. This completely eliminates cold walls in the storage space.
As a result of eliminating cold walls, the storage chamber can be utilised to its fullest.
Just as importantly, a finned tube evaporator enables forced air distribution inside the storage chamber, distributing cold air throughout - enhancing temperature stability and uniformity.
A stable, uniform temperature is achieved by forced air distribution
If a cabinet includes fixtures that provide good ergonomics , effective use of space and store items safely it still must be able to distribute cold air uniformly in the storage area to ensure temperature stability.
The best way to achieve this is with flows of air that are forced in specific directions, directing cold air around into every section within the cabinet. This gives you both temperature stability and uniformity – regardless of the fittings and fixtures you choose to install.
Storage on your terms
Drawers provide a clear overview of the contents ensuring items are not missed at the rear of the cabinet. This arrangement is ideal for first in/first out operations.
Effective use of storage space
Forced air circulation means BioCompact II cabinets have no cold walls. If you use drawers divided up into sections, this also helps you make sure that all the space within the cabinet is put to effective use.
Because the cabinet can be organised to meet specific requirements it provides ease of access to all stored items. Drawers can be extended fully from the cabinet.