Humidity Control in Seed Storage and Preservation

The main reason for seed storage is to facilitate distribution to areas not normally reached, or on a timescale that would not naturally be possible. These seeds should maintain a longevity that makes this achievable.

There are various, more specific reasons why seeds would be stored.

Farmers must keep their seeds for a short period of time until the next growing season, while germplasm banks do so for long periods of time, some theoretically can store seeds indefinitely. There is also forest use or immediate-application restoration.

The new challenges of modern society demand the use of  phytogenic resources to support sustainable development.

It is therefore essential to establish conditions and resources for handling and conserving seeds until use. It is of such vital importance that large public and private funds are earmarked for this purpose.

Reasons to Implement Humidity Control in Seed Preservation

The longevity of orthodox seeds, most cultivated and wild plants,  is increased when moisture content is decreased. The moisture content is in equilibrium with the relative humidity level of the air. If you only intend to preserve the seeds for a single season, moisture levels in equilibrium with 65%RH will suffice. For storage periods of 2-3 years, they must be in equilibrium with an ambient RH of 45%. However, when the target is stable long-term storage, moisture levels must be in equilibrium with 25%RH.

As most storage temperatures are low (below 20°C), the condensation drying method becomes uneconomic and moisture control accuracy is difficult to achieve and even more difficult to maintain. Therefore, most seed stores and banks use desiccant rotor dehumidifiers. This technology can dry up to very low levels of humidity, at low temperatures, and with absolute control of the %RH in the ambient air of the warehouse or seed bank.

Fisair has provided advice and equipment to the world’s leading seed banks and warehouses, where the task of safeguarding the precious contents, requires faultless function 24 hours a day, 365 days a year.

There are many cases we could cite for the storage of seeds, including the multinational Hy Tech Seeds, the most advanced private company in biotechnology development, Monsanto, and public seed banks such as those of the Spanish Plant  Genetic Resources Center “INIA” or the Polytechnic University of Madrid.

The Best Solution to Control Humidity During Seed Preservation

The new DFRIGO series is specially designed for this application. It has a desiccant rotor with a high drying capacity, essential insulation, heat recovery to avoid raising room temperature and high efficiency EC fans.


The DFRD series is optimal for small rooms where there is very little opening of doors. Fisair has worked with large companies with these products such as Hy-Seeds.

DFRD air dehumidifiers picture | Air dehumidifiers with deseccant rotor | Fisair

The DFRA series is optimal for large rooms or where door opening is more frequent. These dehumidifiers are able to reach very dry air conditions and work very well in conservation chambers. Fisair has worked with various reputable multinationals with this equipment, for example, the firm Monsanto.

DF air dehumidifiers picture | Fisair

Application References

Some outstanding references:

    • Hy Seeds
    • Monsanto
    • INIA – UPM Madrid University

    • CIAT 

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