Contributions, Questions, Answers

May 2017

BOS S 3000, drum bearing systems

The known and proven drum bearing systems down to -50 ° C have been revised.

The new systems have a far more powerful isolation and the optimized economic possibility to lay and manage highly organized products down to -86 ° C.

New storage area, new insulation, new operating concept:

Approx. 3000l effective volume
Approx. 4 m² floor space
New, ultra-light storage containers
Temperature range + 10 ° C to -86 ° C
New control panel with touch screen

  • Optional cold water delivery
  • Optional cold gas delivery


November 2011

Rotating devices for erythrocytes

Erythrocytes lose some of their activity under conventional conditions of
static storage at temperatures between +2°C and +6°C (max. 48 days)
in nutritive solutions due to time-dependent stacking at rest.The Red Cross
in Innsbruck has established that samples that were stirred several times
during storage displayed greater viability. Furthermore, other data suggest
that stored RBCs should be stirred or thoroughly mixed at least once per week.
The BOS S 3000/86 storage system from NSC Medical Cooling Systems GmbH,
developed by NNC-MED Consulting, incorporates this as a standard feature. A new
development by NNC, the BOS S RBG storage system, can also be supplied with a rotating unit on request.

'Cascade', the new cell concept from NNC-MED Consulting

Current cold rooms are designed with an insulating wall so as to keep heat from
penetrating into the interior for as long as possible. Advanced designs incorporate
super vacuum insulation panels. NNC uses a different technique to optimize cooling
-- a double-wall design incorporating two insulation panels of equal thickness that are
separated by a plenum chamber. Cooling is effected with (LN2); the decompressed N2
then cools the plenum. This triple-layer separation of the internal environment from external
temperatures results in a greatly extended warm-up time of the internal space and the stored products.

Experiments in a test cell (4,000 mm wide / 6,000 mm high / 6,000 mm deep) at the Development Centre yielded the following results:Warm-up after turning off the cooling:

Heating during the cooling system is off
-40°C to -30°C 29 hours 0.35 K/h
-30°C to -20°C 30 hours 0.33 K/h
-20°C to -10°C 42 hours 0.23 K/h
-10°C to 0°C 54 hours 0.18 K/h
+2°C to +6°C 203 hours 0.019 K/h
-40°C to +6°C 775 hours 0.059 K/h Total test process

We would be happy to develop the right design and optimize operating procedures for you.

The combination of cost-containment,
improved products and more reliable work
processes is a worthwhile goal that we can help you achieve.


August 2010

Why is it so important ..... ? 

to use the right system to store your biological materials properly, monitor them effectively and permanently protect them from damage?

  • So that they don't deteriorate
  • So that they retain their effectiveness
  • So that you can derive added value from these materials
  • So that your materials don't cause any injury to your clients
  • So that you are protected against damage claims

This includes:

Ensuring that enough energy is always available to dissipate incoming heat from the system.

  • Heat that comes in through the insulation
  • Heat brought in by the products to be stored
  • Heat that it is let in when the access area is open

Ensuring that your stored goods are well organised.

  • Searching for items means letting heat into the system
  • Searching means damaging the products
  • Searching means wasting time and money

Ensuring that the right measurement techniques and monitoring locations are used.

  • A buffered temperature sensor is a bad temperature sensor.
  • The heat exchanger is the wrong place to put a reference container for the temperature sensors.

Our experience:

  • It is very important to ensure that enough energy is always available to dissipate incoming heat from the system.
  • It is very important to ensure that appropriate, unbuffered temperature sensors in the right locations can monitor your storage system properly.
  • Buffering with large reference vessels distorts the measurements and prevents the collection of objective data.

We would be happy to tell you more about these issues in a comprehensive consultation. 

Uwe Nehrmann 
NNC-MED Consulting


Juli 2010

Liquid nirtogen technology for storage of Fresh-Frozen Plasma and logistic features

Lehnert, Erik, Scharf, Rüdiger E., Heinrich Heine University Medical Center, Düsseldorf, Germany
Heinrich Heine University Medical Center, Department of Hemostasis and Transfusion Medicine, Moorenstr. 5, 40225 Düsseldorf, Germany

Compressor technology is being used for cooling purposes and storage of blood components. However, this technology has several significant disadvantages, including many mechanical parts, space requirements and high electric energy consumption.

Therefore a reliable, robust and user friendly technology without these drawbacks had to be designed.

We have implemented a BOS-S/040 storage system (NSC Medical Cooling Systems, Hamburg, Germany) for any kind of biological materials (temperature range +10 to -86°C) which meets all requirements including a computer-based storage management system connected to our production system. The installation of 34 systems, each comprising 2.592 standard units of fresh frozen plasma (FFP) in a cube of approximately 2 x 2 x 2 meters was completed in 2008.

In operational use of this technology, the following significant benefits were experienced:

  • The operating costs per stored plasma unit are much lower than before due to
  • a) a significant decrease by 26% in cooling energy costs (electrical energy vs. liquid nitrogen) corresponding to 910 € per 1000 FFP units per year
    a decrease in the net space by 31% requiring 1.5 square meters per 1.000 FFP units
  • c) a reduction in manpower requirement for handling by more than 50%
    d) a reduction in maintenance cost by more than 50%.
  • The stability of the stored products, as evaluated by hemostasis profiling including coagulation factor activities including FVIII:C following freezing and thawing is superior, as compared to the European Guidelines. This result is related to constant temperatures inside the BOS-S/040 system which are warranted specifically during handling procedures due to minimized opened areas and appropriate cooling input.
  • In case of complete charging, the cooling capacity is guaranteed by the manufacturer and, as evaluated, provided indeed.
  • Handling of the stored products by the staff is easy to perform due to usage of pocket computer devices.
  • A detailed visualization of all relevant system data is available including alarm situations.
  • There is a complete documentation of the cooling chain implemented in the data management system.
  • Service operations are reduced to less than 50% due to the robust technical concept of the system.
  • Occupational health and safety are considerably increased because handling is performed at room temperature without ice-covered floors.

The investment into the liquid nitrogen technology pays off shortly because of significant advantages over conventional compressor technology. Drawbacks cannot be seen. Moreover, occupational aspects for staff are evident because handling of FFP can be performed at room temperature instead of working in frosty environment. The complete loading/unloading process is performed and recorded automatically without hard copies and paper work. Most of all, the precise and computer-controlled management of the plasma units guarantees a significantly higher degree of safety for patients and staff. Based on this reliable and robust technology and our experience reported here, a follow-up system is being developed to preserve biological products at temperatures below -150°C, e.g. for red blood cells, hematopoietic progenitor or stem cells.

Storage temperature documentation

Liquid nitrogen technology Storage system for Fresh Frozen Plasma (FFP)

We would be happy to tell you more about these issues in a comprehensive consultation.

Uwe Nehrmann
NNC-MED Consulting


June 2010

What happens if frozen plasma is left lying unprotected in the work area for longer than 5 minutes?

This happens all the time, with little awareness of the significant consequences.

Expensive freezing systems are purchased, processes are tested and one starts out with good intentions, but then:

  1. The freezer has done its job and reports that the plasma has been frozen to a core temperature of -30°C. The surface temperature of the plasma is -40°C, the subsequent storage temperature.
  2. Packs and barcodes are checked again.
  3. The plasma is placed in a container. Insulated/not insulated?
  4. The container is sitting on a trolley.
  5. It is taken to the storage facility (quarantine store).
  6. The plasma is taken out of the container and stored.

How long does this take?

At least 30 minutes elapses between removal from the freezer and placement in the quarantine store, so products are often stored in the refrigerator in the meantime. Sometimes there is a wait until results are received from the laboratory.

Measurements have shown that a considerable change in temperature takes place after holding plasma unprotected even for very short periods. This must be avoided. Appropriate equipment and compliance with guidelines are essential.

What can I do, how should I do it?

The most important rule is compliance with the processes described (SOP). One problem is the lack of technical equipment (proper transport systems). A further point is the arrangement of the functional areas. Ideally, the freezer should be located next to the end storage system, so that the time between removal from the freezer and storage is minimal.

In order to illustrate how the plasma is affected, we have made some measurements.

During post-processing, we placed a sensor at the centre of the plasma pack and recorded the temperature.

In July you will find out about modern installations and their construction, including seamless monitoring of your biological materials store.

We would be happy to tell you more about these issues in a comprehensive consultation.

Uwe Nehrmann
NNC-MED Consulting

May 2010

Why is it so important,

that biological material is stored in an organised manner, with appropriate systems?

It is not very easy to answer this question. It is not simply about the ease of locating the products. The search for products and their storage in conventional systems such as refrigerators, freezers and cold stores entails the danger that the temperature of products stored like this can change significantly, making damage inevitable.
It is a challenge for the industry to provide systems that can prevent such damage.

This includes:

Low product holding times at ambient temperature
Accurate labelling of all stored products and their locations
Short handling times (storage and retrieval)
Protected handling areas, in which stored products are still protected from heat, even though they have left the main store or are yet to be stored.
Rapid response capability of cold-generating equipment. This avoids delays of some hours in reaching the required temperature.

High-quality insulation in order to keep energy requirements low. It should be noted that the topic of energy consumption is unfortunately not considered as a whole. Compressor systems not only generate cold - above all they generate waste heat, which must usually be dissipated with expensive air conditioning systems. The energy requirement of compressor systems can therefore be calculated as follows:

"Input energy of the compressor unit + energy expenditure of air conditioning system" = Total energycoast

Large openings in storage units mean that, particularly at low temperatures (-40°C to -86°C), warm and damp air enters and the system ices up severely. Severely enough that regular de-frosting is necessary. This can be avoided with the right choice of system, saving much energy and effort.

Appropriate temperature sensors and sensor locations. Modern systems work with open, unbuffered temperature measurements. This guarantees correct recording and that the temperature time course is always objectively and correctly registered.

In June you will find out what happens when frozen plasma is left unprotected in the workplace for longer than 2 minutes.

We will be happy to provide you with more information on this topic as part of a comprehensive consultation.

Uwe Nehrmann
NNC-MED Consulting

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