How do you calculate the right LN2 supply tank size for your fertility clinic using cycle volume as the basis?
A worked example makes this calculation straightforward. A fertility clinic performing 500 IVF cycles per year, with a freeze-all rate of 40 per cent and an average of 3 embryos frozen per cycle, is cryopreserving approximately 600 embryos per year. If those embryos are stored across 4 storage dewars with a combined capacity of 3,000 straws, and each dewar has a static evaporation rate of 0.15 litres per day, the combined standby LN2 loss is 0.6 litres per day or approximately 220 litres per year before any access events are counted.
Adding access losses of approximately 0.5 litres per access event at 3 access events per day across all vessels gives a further 547 litres per year in access losses. Total annual LN2 requirement is therefore approximately 767 litres before accounting for top-up inefficiency. A supply tank or cylinder arrangement delivering 100 litres per delivery every 7 to 8 weeks covers this volume with adequate margin. Scaling this calculation to your clinic’s actual freeze rate, storage vessel configuration, and access frequency gives a supply tank specification grounded in real operational data rather than guesswork. Cryolab’s LN2 dispensing range and storage vessel range are both specified with the data needed to run this calculation accurately. CryoGPT can run a tailored LN2 supply calculation for your facility’s configuration. Contact Cryolab to discuss supply infrastructure for your specific cycle volume.
