Dear Colleagues,
We've developed a lightweight web tool for calculating the net storage capacity of an existing cold room from its installed shelving, and we'd value critique from this community before we take it further.
The gap we're trying to fill
The established tools — the WHO Vaccine Volume Calculator, the Immunization Supply Chain Sizing Tool, the UNICEF Cold Chain Weight & Volume Calculator, and the EVM Assistant — all run from demand to required capacity. In practice, the harder half of a capacity gap analysis is often the supply side: establishing what a given room already holds, room by room, with the shelving physically present in it. That work is still typically done in spreadsheets, transcribed from field notes.
What the tool does
- Room-level inputs: facility, room description, length, width, height (cm)
- Per shelf unit: shelf width, shelf length, number of shelves, shelf thickness, floor-to-bottom clearance, floor-to-top-shelf height
- Outputs: gross room volume, net storage capacity (litres and m³), and the ratio between them
- Multiple rooms per assessment, with a to-scale isometric diagram that redraws live
Method
The shelving calculation follows WHO TRS 961, Annex 9, Supplement 3, Estimating the capacity of storage facilities, §2.5.5, applying both the restricted and unrestricted ceiling-height forms and taking the more conservative result. The utilization factor defaults to 0.5 and is user-adjustable within the 0.5 to 0.65 range the supplement specifies. It is displayed on screen and carried into the output, so any result can be reproduced and audited.
Where we'd like input
- Does taking
min(restricted, unrestricted)match how you'd apply §2.5.5 in practice, or should the user select the case explicitly? - Is 0.5 the right default for walk-in cold rooms specifically, or does field experience suggest otherwise?
- What validation would you want before trusting an output for a procurement or gap analysis decision?
- What is missing for the tool to be useful in an EVM assessment or a CCE inventory exercise?
🔗 https://crspace-calc.iseet.co
The tool is under active development. Comments here or to ([email protected]) are welcome, particularly where the method is wrong.
Thank you and best regards,
Amjad
Dear Sirs,
I suggest creating a table listing the various biological products in the immunization schedule, taking into account the tertiary packaging (or the secondary packaging if tertiary packaging is not used). You should place these boxes on each shelving unit's shelves and calculate the actual number of doses that fit into each storage unit—specifically, per shelf.
For example, to standardize storage capacity across different cold rooms, we established a requirement for plastic shelving units measuring 45 cm x 90 cm with five shelves; each shelf can accommodate:
1. 48.000 doses of MR (10 doses/vial)
2. 4.800 doses of MMR (1 dose/vial)
3. 56.000 doses of BCG (10 doses/vial)
4. 5.600 doses of HB (1 dose/vial)
5. 960 doses of Rotavirus (1 pre-filled syringe), etc.
...and so on for the entire schedule.
I do not recommend using a utilization factor of 0,5 or similar. The actual calculation should be based on a layout plan determining the number of shelving units and shelves that will fit. Aisle width must be set at 0,80 m, and shelving units should be spaced 10 cm away from the wall. Additionally, the cold room height must account for the 45 cm height of the refrigeration system's evaporators; this is to prevent direct airflow at temperatures below 0ºC from reaching vaccines that must not be frozen.
Finally, as recommended by the manufacturer, do not remove the vials or pre-filled syringes from the original box. The vials could fall, break, or get lost under the shelving and become contaminated.
Best regards.
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