The 20L liquid nitrogen dewar has become something of a default choice for smaller labs and clinics that do not have the floor space or liquid nitrogen supply infrastructure for larger vessels. It is a genuinely versatile size, but versatility does not mean it is automatically right for every application. Before committing to a 20L liquid nitrogen dewar, there are a few calculations worth doing.
First, look at your daily access frequency. A 20L liquid nitrogen dewar with a wide neck and frequent access will lose nitrogen faster than one used for passive long-term storage. In a busy IVF lab where staff are accessing samples multiple times per day, a 20L vessel may require top-up every five to seven days under normal conditions. If your liquid nitrogen supply logistics make frequent top-ups inconvenient, stepping up to a 35L or 47L vessel may be more practical even if the footprint increase feels significant.
Second, think about what you are storing. A 20L liquid nitrogen dewar configured for canister-and-cane storage of straws will hold a different sample count than one fitted with an inventory rack system. The internal configuration is as important as the headline volume. A properly configured 20L vessel can hold thousands of straws, making it more than adequate for many fertility and veterinary applications.
Third, consider static hold time. The best 20L dewars on the market can hold liquid nitrogen for 100 days or more under static conditions. Entry-level products may manage 30 to 60 days. In a power outage or emergency situation, that difference is the difference between sample preservation and sample loss.
View specifications and pricing for the 20L liquid nitrogen dewar range at Cryolab.co.uk. We can advise on internal configurations based on your inventory.
