Cragside, a Victorian house museum in England, was damaged by severe flooding last year. Keeping Art, and Climate, Controlled
AS anyone who works in a museum knows, art conservators can be slow to embrace change. But for Sarah Staniforth, director of historic properties at the National Trust in Britain, the eye opener came last September, as she contemplated photographs of a torrential downpour that had just invaded the billiard room of Cragside, one of the trust’s Victorian house museums.
Since 2000 catastrophic rainstorms have become so prevalent in England that the trust has gradually retrained its emergency teams to cope with floods, in addition to its time-honored enemy, house fires. Yet at Cragside, as with all of the trust’s 300-plus historic house museums, employees still use a standard British mid-20th-century conservation method — chiefly an electric or hot water heating system that maintains constant humidity levels — to protect irreplaceable treasures, like its painting by J. M. W. Turner and its early Burroughes & Watts billiard table.
And now, in the photographs Ms. Staniforth viewed in her office, Cragside’s carefully tended electric conservation heating system was standing in a pool of water. So were the 19th-century fire irons and ornate wrought-iron fireplace seating unit, which had both rusted, and the billiard table, whose legs would take several months to dry out. (The room finally reopened to the public in late February.)
“That photograph made me feel that we had just been fiddling while Rome burned — or, rather, flooded,” Ms. Staniforth said. “It made me see how important it is to get your priorities right, and not to worry exclusively about the humidity when your house can fill up with water as a result of climate change.”
For more than 50 years conservators around the world have sought to prevent damage to the varied objects in their collections by observing a uniform climate-control mantra: Keep everything in the museum at approximately 70 degrees Fahrenheit and 55 percent relative humidity. Since the 1970s that goal has increasingly been achieved with the help of mechanical HVAC (heating, ventilating and air-conditioning) systems, which typically cope with unforeseen events by working overtime.
But as museum budgets shrink, energy costs spiral, and gradual climate changes make the traditional HVAC system more costly to maintain, conservators and other museum experts are rethinking this model. Should museums add to global warming by continuing to rely so heavily on such systems in the first place? And what happens if unforeseen events put them and other protective measures out of commission? As a first step some are pushing for new scientific research while considering updated versions of old solutions.
A week after Cragside was flooded, such issues were at the fore as Ms. Staniforth moderated a panel discussion on climate change as it pertains to museum collections at the annual conference of the International Institute for Conservation of Historic and Artistic Works. The forum was the brainchild of the institute’s president, Jerry Podany, the chief conservator of antiquities at the J. Paul Getty Museum in Los Angeles, who believes the panel was the first of its kind.
Mr. Podany said the meeting was long overdue. “We may not ever get rid of HVAC systems, but we have been on a roll where the only choice was to turn to them,” he said. “I think that we need to take a hard look at our alternatives.”
A major issue confronting museums is to figure out whether their current climate guidelines can be refined. Although they have been debated for centuries, those in use today date to 1956, when Harold J. Plenderleith, a conservator at the British Museum, published “The Conservation of Antiquities and Works of Art,” the first comprehensive guide on the subject.
(The British Museum’s scientific research laboratory was set up in 1920, after conservators realized how badly artifacts had deteriorated when they were stored in the tunnels of the London Underground during World War I. Archaeological iron rusted, bronzes developed patches of powdery green corrosion, and some pottery and limestone objects developed salt crystals because of high humidity levels.)
In 1978 Garry Thomson, a conservator at the National Gallery in London, expanded on Plenderleith’s ideas in “The Museum Environment,” with a specific focus on the interior climate.
But some conservators maintain that Mr. Thomson’s recommendations have since been taken out of context. George Bisacca, a panel-painting specialist at the Metropolitan Museum of Art in New York, said Mr. Thomson’s prescription was for wood-panel paintings, which are especially sensitive to changes in humidity. Wood expands and contracts as it absorbs and releases moisture, while the paint expands and contracts at a different rate, which eventually leads to blistering and cracking.
Mr. Bisacca said that since the 19th century, when many more paintings began traveling internationally, most panel paintings have cracked, in part because of the resulting change in humidity levels, combined with cradling, a pervasive and problematic 19th-century restoration technique. (Conservators often reduced the panel to half its thickness and attached a restraining grid to keep it flat.) At the time of this interview Mr. Bisacca was on his way to Madrid to work on one such panel: the “Adam” section of Dürer’s 1507 diptych “Adam and Eve” at the Prado; its surface cracked long ago in dozens of places.
“If you can keep that relative humidity constant,” he said, “then you stop that constant process of expansion and contraction. But people who don’t understand the mechanisms involved have taken that and applied it everywhere on earth.”
While Thomson’s conclusions make sense for panel paintings — or those acclimatized to Britain’s relatively humid weather — they may not be as appropriate for other climates, or for artworks made from different materials.
Marble, for example, withstands far greater extremes of temperature and humidity, as do some ceramics, metals, plastics, mosaics and glass. Yet many artworks are composites, like an illuminated manuscript fashioned from parchment, ink, paint, wood, leather, metal and jewels — all materials that have different responses to temperature and humidity.
Consider the infinite possibilities, and it is little wonder that conservators maintain similar guidelines for almost everything, with major exceptions for archaeological iron and bronze, which need to be kept very dry, and ivory, which can fall apart unless it is adapted to new conditions very gradually.
A 70-degree temperature also works well for something museum directors want to attract: people. And by now a climate of approximately 70 degrees and 55 percent relative humidity is required under most art-lending agreements.
Last year Nicholas Serota, the director of the Tate in London, began urging museums to investigate whether the existing guidelines can be applied with more subtlety. Together with Mark Jones, the director of the Victoria and Albert Museum, he presented the issue to the Bizot group, an alliance of the directors of some of the world’s most prominent museums, and is now working with British conservators to figure out where to begin.
First, more detailed research will be needed on what various objects actually require. Some is already under way at conservation and study centers like the Getty’s, the Canadian Conservation Institute and the Center for Sustainable Heritage at University College, London. The Image Permanence Institute at the Rochester Institute of Technology has integrated some of its findings into computer programs that can predict damage in many different materials. Conservators can use the system to play with temperature and humidity ranges to see how far the limits can be pushed.
Other efforts are under way to tweak existing climate control systems. One possibility is a wider use of microclimate cases: vitrines that keep groups of similar objects at their own specific humidity levels, so that the air in the rest of the room does not have to be conditioned so stringently. While some are now regulated by miniature HVAC systems, most use what are known as passive, or nonmechanical, measures: a vitrine is fitted with a layer of material, usually silica gel, that buffers the environment by absorbing or releasing moisture as necessary.
While display cases like this exist in museums around the world, the Victoria and Albert has made a commitment to use more of them as it opens new galleries rather than installing HVAC systems. The museum has already taken this approach in its new sacred silver and stained-glass galleries, which opened in 2005; its new jewelry gallery, which opened last year; and the new medieval and Renaissance galleries, opening in November.
Other proposals include a wider use of what Michael C. Henry, a partner in the New Jersey architectural and engineering consulting firm Watson & Henry Associates, calls “smart” ventilation. Before the advent of HVAC systems, Mr. Henry said, buildings were constructed with features that helped to regulate the temperature naturally: windows that let in cooler air, towers that allow warm air to rise and skylights that open to release it, as well as greater thermal mass, which keeps temperatures relatively stable. But now he calls this “fugitive knowledge,” because many architects no longer know how to make these things work.
Mr. Henry has created ventilation plans for many museums and historic houses around the world. At Redcliffe, a pre-Civil War plantation on the banks of the Savannah River in South Carolina, his scheme includes putting an exhaust fan in the attic to pull filtered air through an unused basement window. For Manzil-e-Meher, a new archive in central India for the papers and personal effects of the mystic Meher Baba, who died in 1969, ductwork has been installed throughout the building, and the climate is managed by intake and supply fans.
Similarly low-tech methods may have a place in large museums. Mr. Jones suggests that employees can close off a few sensitive galleries if the weather is particularly humid; limit crowds, which can heat up and humidify a room quickly; and ask visitors to check wet raincoats. Mr. Serota suggests encouraging visitors to keep their coats on in the dead of winter, to avoid the dryness central heating causes.
Historic house museums are on the front line in the battle against climate change. Most manage already without HVAC systems, which are hard to install without destroying the historical integrity of a building. The National Trust in particular, with more than 300 houses, is something of a green museum resource center. Since the 1980s it has also received grants from the British government to find low-energy ways to protect collections.
In coping with the increase in heavy downpours, which bring floods, Ms. Staniforth’s conservators have gradually installed wider gutters and leaders and placed medieval-style spouts at the base of parapets that can quickly drain off large amounts of water. And they routinely inspect and shake out textiles and wall hangings to guard against moth and carpet beetle infestations, which have increased as England’s climate has warmed.
Yet even the greenest building can falter. Cragside is a case in point. As well as being a gloriously appointed Victorian house museum, it is an early example of postindustrial sustainable architecture: completed in 1870, it was the first building in the world to use hydroelectricity, with its lights and elevator powered by a water pump and turbine engine fed by a nearby stream.
The billiard room flooded in September because rain had collected on the roof. But the stream had also overflowed, inundating the newly restored pump and power houses.
Although new gutters and spouts will probably keep the roof from flooding in the future, Ms. Staniforth has not yet figured out how to handle the stream. For now, she said, “I think we’re just keeping our fingers crossed.”
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