Case Study: Indoor Air Quality Monitoring and Environmental Control in Museums for Conservation and Visitor Health and Wellness

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Museums as both civic spaces and a place to store and display historical artifacts require good indoor air quality to fulfill both of their core functions. 

The importance of the indoor environment and IAQ in museums is twofold.

One, as spaces for the display of historical objects for the public, the conservation and preservation of heritage artifacts that are exhibited is a core function of museums. As such, climate control and removal of potentially damaging pollutants is a necessary function of exhibition facilities.

Two, a welcoming and comfortable environment that is suitable for visitor comfort and encourages increased attendance.

Both goals are especially important in the subtropical climate of Hong Kong, where high heat and humidity are not conducive to human comfort or preservation of historical artifacts.

According to a survey of 115 European heritage sites, the top 3 most common environmental factors that cause damage to artifacts are in order, humidity, temperature and air pollution (Dahlin, et al, 2013), all of which fall under HVAC and climate control. High humidity can cause mold damage and encourage pests, which coupled with temperature changes can cause condensation and moisture damage to paper, wood, cloth and pigments.

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Best practices for display exhibits

Neither local nor international standards directly regulate cultural artifacts, however, various organisations such as the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the International Council of Museums – Committee for Conservation, the International Institute for Conservation of Historic and Artistic Works and ISO standards for archival and library materials are commonly used as references for storage of delicate and significant objects.

While standards vary, they commonly suggest the maintenance of stable temperatures near generally accepted ‘room temperature’, around 20 degrees celsius and a stable and low relative humidity of 50%, kept throughout the year.

More extensive protection of irreplaceable sites such as “The Last Supper” painting in Milian, Italy even include filtration of outside air to remove potentially damaging pollutants such as Nitrous Oxides, Ozone, Particulate Matter and exhaled Carbon Dioxide from visitors. The structure was also converted to a sealed, environmentally controlled chamber and kept under positive pressure to stop infiltration of pollutants from outside air. In addition, visitor numbers and length of visit are strictly controlled.

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The local context

In Hong Kong, the Palace Museum is host to exhibits of high historical and cultural value, including visiting exhibits of foreign treasures, which necessitates more strict levels of IAQ control and monitoring.

It is currently rated Good class under the Environmental Protection Department IAQ certification scheme and museum staff have stated they follow the “highest international standards”.

A real time monitoring system was also installed to monitor air using 250 wireless devices inside the building to achieve wide coverage while a cloud connection lowers staffing requirements.

Conclusion

To improve service and allow for exhibition of valuable historical artifacts from abroad and better fulfill the core mission of educating and entertaining the public and supporting the arts, history, science and culture that is borne by museums, IAQ management should be viewed as a core function and mandate of museum facilities.

References

Dahlin, E., Grøntoft, T., Wittstadt, K., Drda-Kühn, K., Colombini, M-P., Bonaduce, I., Vandenabeele, P.,
Larsen, R., Potthast, A., Marincas, O., Schieweck, A., Thicket, D., Odlyha, M., Andrade, G., Hackney, S.,
McDonagh, C., Ackerman, J. J. (2013). EU project MEMORI. Grant agreement no. 265132.
Measurement, Effect Assessment and Mitigation of Pollutant Impact on Movable Cultural Assets. –
Innovative Research for Market Transfer. Project Final Report. NILU OR 15/2014.
https://www.nilu.no/apub/27637/