Environmental Control in National Trust Properties

The paper describes the issues and processes associated with controlling the internal environment in historic National Trust buildings that are open to the public, with the aim of slowing the rates of deterioration of the collections, and decorative interiors, without causing damage to the structure. The paper shows how environmental monitoring is providing knowledge of the building performance prior to any services project and also sets out the current National Trust Environmental Control Strategy. Conservation heating is proving extremely successful at stabilizing environmental conditions and reducing the remedial conservation requirement of the collections. Other control methods, such as buffered microclimates and dehumidification are mentioned briefly, along with the current issues of ventilation, choices of insulation and fuel.

Figure 1 Psychrometric chart.

Comparing the existing conditions monitored with the desired target area on a psychrometric chart demonstrates the required approach.

Figure 6 Castle Drogo, Devon, designed by Lutyens in the early twentieth century, where a Trend BMS controls a wet heating system humidistatically for display rooms and thermostatically for domestic accommodation; oil boilers to be replaced in 2009 with a 400kW woodchip boiler, with the woodchip to be harvested from oak coppice on the Drogo estate. (©NTPL/Dennis Gilbert)

Linda Bullock

Linda Bullock graduated with a BSc (Hons) in Physics and worked for Kodak and National Gallery, London researching lighting and environmental issues. Positions at Instituut Collectie Nederland, Amsterdam and the National Trust followed, where she provided preventive and environmental advice for museums and historic houses. Now a consultant, she sits on the Paintings Committee of the Church Buildings Council and is an accredited conservator–restorer (ACR).

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Donhead Publishing 2010