Cold Chain
Installation, Loading and Maintenance


Installation of cold chain equipment must be done in the adequate room. The room must be accessible for vaccine reception and delivery, large enough, in good building conditions (roof, ceilings, floors, electrical services, etc.) and secure. Useful information can be found in WHO’s Guideline for establishing or improving primary and intermediate vaccine stores and WHO-UNICEF’s Effective Vaccine Store Management Initiative.

Remember that cold chain is not only about refrigeration equipment: storage space for diluents, packaging materials, cold boxes and icepacks should be also considered. A proper planning of the storage room and all needed pre-operation must be completed before installing any active cold chain equipment.

Manuals shall be provided by the manufacturer with each equipment with clear descriptions on procedures for installation, operation, diagnostic and maintenance. Nevertheless, general recommendations for a proper installation of cold chain equipment include:

  • Place it out of the sun, away from any source of heat (stove, radiator) and protected from dust.
  • The room must be at least 20 m3 of volume, be well aerated and cool if possible; always respect the ambient operating temperature range indicated by the manufacturer.
  • Make sure there is clearance between the unit and a wall, partition or other equipment in order to allow air to circulate and facilitate maintenance; the clearance distance should be of at least 25 cm for compression type refrigerators and 40 cm for absorption type refrigerators.
  • The refrigerator/freezer should be placed on blocks or pallets to avoid direct contact with the ground, protect against humidity and increase heat evacuation.
  • Install it horizontally to ensure good circulation of the cooling fluid.

For equipment powered by electricity, it is essential that it is installed according to the national standards of electrical equipment installation. Devices not having an integrated voltage stabiliser, must be protected relying on standalone voltage stabiliser. This is critical wherever voltage fluctuations exceed ±15% of rated voltage (or the refrigeration equipment manufacturer’s voltage tolerance, whichever is lower).

After the setup of a compression type refrigerator, it is recommended to wait 24 hours before starting it. This is to allow oil lubrication of the compressor, which could have left in the pipes during transport, to go down in the compressor. In the event of starting without waiting, the lack of oil could deteriorate the compressor.

Absorption type refrigerators must be perfectly vertical. To check and to adjust it, a plumb line and a spirit level are located inside the fridge. No waiting period is necessary before using an absorption refrigerator. It can be started immediately.

When possible, and especially if not having in-house capacity, it is advised to outsource the installation of the cold chain equipment. This is especially critical when acquiring SDD equipment or walk-in cold/freezer rooms. It is recommended that full/final cost of the payment for cold store install costs be withheld  until a full commissioning test has been completed satisfactorily. Typical commissioning tests should include:

  • Cool-down time: Start the refrigeration unit when the room is empty and the same temperature exists inside and outside the room. Keep the cold room door closed during the test. Record the time needed for the internal temperature to drop below +8°C. Run the test for at least 48 hours.
  • Running test: Record the number of hours that the compressor runs with the door closed and the room empty. Monitor the internal and external temperatures, the evaporator and condenser temperatures, and the pressures of the system. Measure the maximum temperature difference in the cold room and record the locations of any warm and cold spots.
  • Temperature-rise test: Cut off the electricity supply to the room and measure the period required for the internal temperature to rise to 5°C above the normal operating temperature.
  • Control and monitoring equipment tests: Test the operation of the automatic duty-sharing, temperature control and temperature-monitoring and alarm equipment. If computerised temperature monitoring is used, load, configure and test the software.
  • Stand-by generator operation test: Check the power output of the stand-by generator and the operation of the automatic mains failure control system. Run the generator continuously for 48 hours under load.

For detailed installation instructions for refrigerators and freezers, check EVM Model Standard Operating Procedures, Consolidated version, with user guide, from the Effective Vaccine Management Initiative.


Basic recommendations for loading the refrigerator units with vaccines, include:

  • Do not store unauthorised products (like food or drinks) in refrigerators used for thermo-sensitive products storage. Overload and continuous opening reduce the performance of the equipment and affect negatively temperature stability.
  • Keep all vaccine stacked on shelves or baskets, not on the floor.
  • Do not append the boxes together or in contact with the walls: leave a space between them to allow cold air to circulate.
  • Be careful, not to store freeze-sensitive products in the coldest part of the fridge (in contact with the evaporator): in the bottom for horizontal/top door fridge and on the top for vertical/front door fridges.
  • Do not store any vaccine in the doors of vertical/front open refrigerators.
  • Keep all vaccines in its inner cardboard box. There should be no loose vials in the store.
  • Products should be quickly identifiable in order to reduce the time with the door open. Names and expiry dates must be located on the front and be readable as soon you open the fridge.
  • Store the vaccine systematically and keep together the contents of each batch.
  • To facilitate handling and reduce the time opening the door, apply a positioning rule. For example, the rule: expiration date closest to the left of the shelf and the farthest to the right. Products with expiry dates closest leave first, then date more distant.
  • If there is enough place, the diluents may be stored in the refrigerator also. Remember that vaccine produced by one manufacturer must never be used with diluent produced by another.
  • Each refrigerator must be equipped with a thermometer and other mandatory indicators.

For further details on arrangement of vaccines with specific rules for using front or top-opening refrigerators, read WHO’s Immunisation in Practice: A practical guide for health staff.


Cold chain equipment needs periodic maintenance and repairs. Maintenance should be planned from the moment of installation by defining a regular schedule of basic tasks to be implemented by on-site workers.

These regular tasks should include:

  • Temperature control and monitoring: This will allow the review of the system performance. Check and record the temperature twice a day. A convenient routine is to do so, first thing in the morning when opening the facility, and last thing in the evening before closing it. Analyse the trend of recorded temperatures and report and investigate any abnormality.
  • Visual inspection inside: Weekly check if excessive ice has accumulated in the interior and the evaporator plate. Ice reduces device performance, requiring more electricity, gas, kerosene or solar power. Whenever the ice on the inside lining is thicker than 5mm or at least once per month, defrost the unit and clean and dry the interior of the refrigerator and/or freezer. Regularly check for signs of damage, including corrosion and deformation of the door or lid seal. Carry out repairs as necessary. A door not closing properly or being open too often are the main causes of excessive formation of ice.
  • Visual inspection outside: monthly clean and wipe the dust accumulating on the back of the refrigerator and/or freezer (condenser and cooling unit). Excessive dust may reduce device performance. Do not allow rubbish and packaging to accumulate in the vaccine storage area. It is essential to maintain free air movement around the condensing units. Regularly check for signs of rust and carry out repairs as necessary.
  • Visual inspection of the source of energy: Maintain the source of energy (mains, voltage stabiliser, batteries, solar panel, etc.) according to the instructions of the manufacturer.

For detailed maintenance instructions for the different type of refrigerators and freezers, including defrosting procedure, check EVM Model Standard Operating Procedures (Consolidated version, with user guide), from the Effective Vaccine Management Initiative.

Basic repairs, such as replacing fuses or repairing rusty surfaces can be performed by on-site workers. To enable this, training of staff is essential. On-site training can be provided by the installation service provider at the time of equipment installation or during a follow-up visit. Other more complex repairs, such those affecting the thermostat, the controllers or the cooling unit, will require a local, regional or central workshop technician. An important element of the maintenance plan is to identify suitable technicians at one or several of these levels able to perform scheduled and emergency repairs.

In any case (regular maintenance such a defrosting or in a breakdown), it is imperative to have the means to relocate the vaccines in another unit during the intervention. The relocation can be done using passive means such cool boxes. Consequently, accurate inventories of the equipment and the basic spare parts are a corner stone of the cold chain maintenance system.

Any malfunctioning, maintenance or repair performed must be consistently reported. This will allow making the correct decisions when a particular unit is not reliable and reviewing the reasoning behind the selection of particular models or technologies in a given context.

Be aware that some types of temperature monitoring equipment are battery powered. These devices contain a non-replaceable battery with a minimum operating life of 2 years from the date of activation. It is essential to include the replacement of these devices as part of their routine preventive maintenance programme.

Decommissioning and Disposal

Decommissioning and disposal are the last stages in the life cycle of the cold chain equipment. When the equipment become technically obsolete or repair and maintenance costs become higher than the remaining value of the equipment, decommissioning and disposal should be considered.

There are several disposal methods depending on the degree of obsolescence of the cold chain equipment: un-repairable, ineffective for vaccines, costly, surplus due to down-scaling of operations, etc. The most common methods for disposal are: donation, transfer, sale, recycling (spare part harvesting) or destroyed.

The development of a decommissioning and disposal policy and practical guideline & tools, is recommended. It should provide guidance on:

  • Expected lifespan of the equipment in order to get the best performance and cost-effectiveness.
  • Budgeting decommissioning costs.
  • Decision process and administrative steps on assets for decommissioning (considerations, responsibilities and traceability).
  • Available disposal channels and decision criteria.
  • Human and technical available means (for packaging, freight, transport, etc.).
  • Environmental considerations.

Obsolete cold chain equipment can be hazardous to people and the environment; therefore, the applied disposal method must consider at least the following aspects:

  • Cold chain equipment could have been used for laboratory purposes, storing potentially infectious substances such as: biological material, blood, and body fluid or excreta. In such cases, decontamination by a trained technician should be performed.
  • Compression type refrigerators are loaded with a coolant fluid agent (refrigerant) having a high Global Warming Potential. Refrigerant may be recovered, destroyed, reclaimed for sale, or stored safely to prevent emissions.
  • Some refrigerators and freezers may have heavy-metal components that should be safely removed prior to final disposal.
  • Plans also need to be in place for the safe disposal of used temperature monitoring devices. Ideally, they should be recycled in accordance with local regulations because they contain valuable materials, some of which may be toxic. Electronic devices marketed in the European Union will generally be marked with a warning symbol indicating that the product should not be sent to a landfill.
  • Solar equipment (panels and batteries) should be handled separately with its own assessment and disposal procedure.

For further information on decommissioning and disposal, refer to UNICEF guidance on Decommissioning and Safe Disposal of Cold Chain Equipment.

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