A newsletter for alumni, students, and friends of the Mechanical Engineering Department at the University of Wisconsin-Madison
How do you keep the hides of the Somalian wild asses from disintegrating yet allow museum visitors to be comfortable? And what's the best way to preserve and display a woolly mammoth without forcing viewers to walk through a freezer?
The Field Museum's expansive halls and atria provide unique challenges for HVAC control and artifact preservation.
These were a couple of the questions that Assistant Professor Douglas Reindl and Professor Sanford Klein had to ask themselves when Chicago's Field Museum of Natural History hired them to study the heating, ventilation, humidity, and air conditioning systems in the massive, century-old structure. Reindl summarized the need: "How are we managing to destroy in a few decades artifacts that have lasted hundreds of years? And how can we prevent that? We can either put artifacts in a secure, safe environment and keep people out or we can compromise, put them in a display where people can see them."
The museum had previously worked with Reindl in the design of a new HVAC system and that led naturally to this project. Reindl was joined by Professor Klein and graduate student Janeen Ault in the new study to understand what was causing the deterioration of some artifacts and to decide what to do in the next five years to prevent further damage to stored and displayed pieces. They started by setting up monitors in various areas within the building to get a year's worth of information about current conditions. They also researched what other museums, like the Smithsonian and Getty were doing to protect their collections.
Graduate student Janeen Ault programs air monitoring equipment.
"The Field Museum was built long before air conditioning, and it is very large," said Klein. "Its equipment is very old; there is no humidity control at all in some parts of the building. Everything is done in parts and pieces and inadequately. In some areas, air conditioning and heat leak through exit doors, so it's difficult to keep conditions constant. Museum curators are experts in their fields, but they don't know much about controlling humidity and temperature. And we do know that different materials need to be kept in different conditions."
Their work was further complicated by the fact that 95 percent of the museum's collections are in storage rather than on display, and also that large areas of the building are used only by researchers and are not open to the public. The stored items also had to be protected but in a way that allowed scientists to operate.
The research team came up with lists of short-term, intermediate, and long-range remediation recommendations. Included in the first list was advice to replace the weatherization seals on all outside emergency doors, relocate thermostats to more representative spots away from doors, demolish a wall that was cutting off one exhibit hall from movement of air from another, add humidifying equipment, and reduce intake of outside air. A significant amount of damaging air pollution comes from nearby Chicago traffic and parking lots. Contaminants from auto exhaust react chemically with the artifacts to cause irreversible damage.
On the more long-term to-do lists were recommendations to continue to
upgrade all the air and humidity systems, install air filters, and if
possible, pressurize the building slightly to reduce outdoor air
infiltration rates. Reindl noted that funding for the Field Museum's
projects is always a challenge and that the museum managers must still
address such much-needed modernizations as installing sprinklers,
improving roof drainage, and replacing outmoded windows.
ME Newsletter is a periodic publication of the University of
Wisconsin-Madison, Department of Mechanical Engineering. Correspondence should be sent to the address below.
Editor: Gail Gawenda
Designer: Lynda Litzkow
WINTER 2000 Contents