Monitoring environmental conditions in the museum

Humidity and temperature in the museum
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Humidity and temperature in the museum

Concern for the well-being of exhibits is one of the most important tasks faced by museology.

For the purpose of keeping the collections in the best possible condition, it is imperative to provide them with appropriate and constant microclimatic conditions, such as temperature and humidity. These parameters have a direct impact on the condition of the museum collections – they can be both positive and negative. Ensuring the right and as constant as possible microclimate in the exhibition halls, storage rooms or conservation studios is often a challenge. There are numerous factors influencing the fluctuation of these parameters, such as old buildings, visitors in wet outer garments, uncontrolled opening of windows, too tight joinery or economic limitations – the list goes on.

The greatest importance for keeping museum pieces in good condition is to maintain relative humidity at an appropriate, constant level.

This is of particular importance for collections with high absorbency, e.g. paper, leather, textiles, but also for materials susceptible to corrosion. Changes in the ambient water content lead to faster deterioration of objects through discolouration, deformation, swelling, shrinking, rusting or accelerated decomposition. The optimum humidity level for most museum pieces is 40-60%, and ideally should be maintained at 50%. Exceeding 65% can lead to the growth of mould or fungi, which can seriously damage exhibits in a short period of time. One should bear in mind that museums are places conducive to microbial growth, due to the high turnover of people and the variety of sensitive materials collected, such as wood, leather or paper.

The second important, albeit minor, parameter that influences the museums is the temperature. It is usually adjusted to the comfort of the people staying in the exhibition rooms, ranging from 16 to 25°C. Higher parameters, as with humidity, can encourage the growth of undesirable organisms. Too low a temperature, however, can contribute to increased fragility of objects and other mechanical damage.

What are the benefits of monitoring environmental conditions

Monitoring environmental conditions on a continuous basis is extremely useful for conservators and other museum employees. It will make it easier to locate areas where humidifiers or moisture-absorbing gels should be placed, to seal windows or to install additional curtains on doors. It will also help to choose the most suitable locations for sensitive objects, decide on a separate room or the positioning of showcases. The readings provide valuable guidance for engineers responsible for the design and correct operation of ventilation and air-conditioning systems. The systematic archiving of readings will enable an in-depth analysis of the changes taking place, catching irregularities in seasonal cycles and thus making the right decisions and generating savings. All this will contribute to ensuring the safety of the collections and enable them to be kept in the best possible condition for a long time.

Adaptation of the conditions to the nature of the collection

It should be borne in mind that the temperature and humidity ranges given may be different for the various groups of museum pieces and should be adapted to the nature of the collection on an individual basis. When choosing a storage or exhibition site, it is essential to take into account the microclimate in which the exhibits have previously been stored. To avoid ‘shock’, it is a good idea to analyse the temperature and humidity of the storage location of the object, at least for the last year, and confirm the positive condition of the object. The absence of damage will be evidence that the previous storage conditions were optimal and safe for the object in question.

Benefits of monitoring environmental conditions

Monitoring environmental conditions on a continuous basis is extremely useful for conservators and other museum employees. It will make it easier to locate areas where humidifiers or moisture-absorbing gels should be placed, to seal windows or to install additional curtains on doors. It will also help to choose the most suitable locations for sensitive objects, decide on a separate room or the positioning of showcases. The readings provide valuable guidance for engineers responsible for the design and correct operation of ventilation and air-conditioning systems. The systematic archiving of readings will enable an in-depth analysis of the changes taking place, catching irregularities in seasonal cycles and thus making the right decisions and generating savings. All this will contribute to ensuring the safety of the collections and enable them to be kept in the best possible condition for a long time.