Museums, archives and libraries


Museum, archive and library artefacts and documents are often delicate, rare and valuable – and almost always difficult to keep in good condition. Without proper humidity control, you can be faced with all kinds of problems with these priceless parts of our cultural heritage, including:

  • Deterioration that often is near-invisible until serious or fatal damage has occurred
  • Mould, mildew, fungal and bacterial growths
  • Cracking, shrinkage and swelling of artefacts made of wood, textiles and paper
  • Corrosion of priceless metal objects
  • Poor working conditions for staff storing and working on key materials


Controlled humidity means
we can preserve our heritage

Humidity challenges in museums, archives and libraries

Historical materials – be they books, documents or artefacts, or films and tapes documenting our history – are a key part of any society’s culture. They’re irreplaceable – they simply can’t be produced again.

Unfortunately, they easily get damaged when exposed to high relative humidity. Fluctuating levels of moisture in the air – affected by weather, seasons and climate – can make materials deteriorate as a result of a wide range of processes – often near-invisible until the fatal damage is done. Many such items are organic in origin, easily affected by mould, mildew, fungal growths and bacterial activity – all of which thrive in high-humidity environments.

Varying levels of airborne moisture in and around hygroscopic materials – such as wood, textiles, carton and paper – can also make them crack and alter size, resulting in significant damage that is irreparable and can destroy their historical, academic and cultural value.

Metal objects are easily affected by rust and corrosion, while materials such as films, tapes and documents all tend to degrade in uncontrolled humidity – and such degradation is irreversible.

Heating, fans and ventilation simply aren’t capable of dealing with the problems stemming from uncontrolled airborne humidity – as well as being extremely expensive to run. Replacing one body of air affected by uncontrolled, fluctuating levels of humidity with another – under just as little control – cannot do away with the problem.

Preventive action

Museums and libraries are often – in part, at least – public places. This means there are certain areas in which ambient air will enter, and its specifications will always be affected by natural ventilation.

The only realistic way to preserve and protect the kinds of materials stored and put on display in museums, archives and libraries is to maintain levels of relative humidity below 50%. And this has to be done all year round, irrespective of weather conditions, and regardless of visitor density.

Cotes adsorption dehumidifiers are an energy-efficient way to ensure reliable, humidity-controlled environments, doing away with expensive-to-run heating that doesn’t deal with humidity fluctuations and independent of outdoor weather conditions and fluctuations in relative humidity.

They’re small, lightweight and easy to place just about anywhere. There are also special models that you can move around to deal with changing needs, ad hoc requirements and special events.



How you benefit

  • Maintain stringent, reliable control of air conditions inside museums, archives and libraries where you store and work on key materials
  • Prevent corrosion and other humidity-related damage to historical artefacts of all kinds
  • Low energy consumption and minimal operating costs while ensuring a humidity-controlled environment
  • Service and maintenance costs kept to a minimum
  • No need for manual operation, emptying of water containers, etc.

Cotes solutions stand out

Cotes solutions for controlling humidity in museums, archives and libraries are
  • Easy to install in confined spaces, because they are light and compact
  • Sleek, elegant casing – can be mounted even where highly visible
  • Built for reliability and a long service life
  • Energy-efficient, with heat recovery that can save up to 20% on energy bills
  • Easy to move around, if needed