Different components, different equipment
Whole blood and red cell concentrates are commonly stored refrigerated in the +2 to +6 °C band. Platelets are not refrigerated at all: they are generally held at +20 to +24 °C on a continuous agitator in a platelet incubator. Plasma is frozen and stored in a plasma freezer at temperatures set by the applicable standard, typically well below −18 °C. Check the exact limits in your own standards; they vary between countries and editions.
| Component | Typical storage | Equipment |
|---|---|---|
| Whole blood, red cells | Refrigerated, commonly +2 to +6 °C | Blood bank refrigerator |
| Platelets | +20 to +24 °C with agitation | Platelet incubator and agitator |
| Fresh frozen plasma, cryoprecipitate | Frozen, limit set by standard | Plasma freezer |
| Transport | Within the limits your procedure sets | Validated transport boxes |
Why blood bank refrigerators differ from ordinary ones
The +2 to +6 °C window is narrow. An ordinary commercial refrigerator can swing several degrees as the compressor cycles and can warm sharply during defrost. A blood bank refrigerator uses forced-air circulation, a sensitive controller and a design that keeps the whole cabinet within band, including during defrost and after the door is opened. Ask suppliers for uniformity data across every shelf or drawer, under a full load, at a stated ambient temperature.
Monitoring, alarms and records
- Continuous temperature recording, either a chart recorder or an electronic logger, with a probe that represents product temperature rather than air temperature.
- Audible and visual alarms for high and low temperature, set inside the storage limits so staff can act before blood goes out of range.
- Power-failure alarm with battery backup so the alarm still works when mains power is lost.
- Door-open alarm and, ideally, remote alerts to the on-call person.
- An independent thermometer or logger for daily checks against the controller reading.
Defrost, door openings and recovery
Two moments test a blood bank refrigerator: defrost and a long door opening. Every evaporator collects frost and has to clear it, and a poorly designed unit lets the cabinet warm during that cycle. Ask how defrost is handled and what the cabinet temperature does during it. Then ask how quickly the cabinet returns to band after the door has been open for, say, a minute while staff search for a unit of a rare group.
Small design details help here: an inner door or individual drawer fronts reduce the amount of cold air that spills out, and a fan that stops when the door opens keeps warm room air from being pulled in.
Drawers, shelves and layout
Many blood bank refrigerators use pull-out drawers or baskets so bags can be organised by group and expiry and found quickly with the door open for as short a time as possible. Glass doors let staff see stock before opening. Interior lighting and clear labelling of each drawer reduce search time. Leave room for air to circulate; packing bags tightly against the walls creates cold and warm spots.
Power and site conditions in India
Blood centres need reliable power. Connect blood storage equipment to the emergency supply circuit, check that your generator or UPS can start the compressor, and protect against voltage fluctuation. Place units in a ventilated room with enough clearance for the condenser; a crowded, hot store room shortens compressor life and makes temperature control harder.
Agree a preventive maintenance and calibration schedule with the supplier at the time of purchase, and keep the records with the equipment file. Inspectors usually ask for them.
Buying checklist
- Confirm which standard or specification the unit is designed and tested to, and ask for the test report.
- Check the temperature range, uniformity and recovery data against your standard.
- Ask what alarm and recording features are included as standard and which are extra.
- Ask about local service response, spares and calibration support.
- Confirm installation qualification and operational qualification support if your quality system requires it.
Frequently asked questions
- Can platelets be stored in a blood bank refrigerator?
- No. Platelets are generally stored at room temperature, around +20 to +24 °C, with continuous agitation in a platelet incubator. Follow your applicable standards for exact conditions.
- Who sets the requirements for blood storage equipment?
- Health authorities, licensing bodies and accreditation standards set them, and WHO publishes guidance on blood cold chain equipment. Your blood centre's licence and quality manual tell you which apply.
- Why is the alarm set inside the storage limits?
- So staff have time to respond. If the alarm only sounds when the limit is crossed, blood is already out of range. Setting it slightly inside the limits gives a warning while there is still time to fix a door, a plug or a fault.
