Climate Control; Protecting History Is a Full-Time Job

Article excerpt


There are unseen dangers in the air that flows through the National Archives II in College Park. They seep through ducts, vents and cracks in windows. They creep slowly and relentlessly, a constant threat to the nation's most treasured documents. They are heat, cold, humidity and dirt.

The prospect of increased water or dust in the air might not strike fear into the heart of the average person, but at the home of some of the nation's most important historical records, humidity and other natural forces like heat and sunlight are a major concern.

Too much or too little of any of these things will cause important papers to expand and then shrink, prized photographs to warp and priceless filmstrips to crack.

George Kahl's job is to make sure the 1.8 million-square-foot building accomplishes what it was designed to do: house and protect some of the nation's most prized records.

Mr. Kahl is a program manager with Consolidated Engineering Services, working out of the National Archives II, which houses nearly 5 billion pieces of historical paper and serves as one of the nation's top spots for research on the United States' past.

"This is pretty dynamic," Mr. Kahl says, as he walks swiftly through the building's underground city of pipes, boilers, and ducts. "It's a challenge to run a building this size that has this type of mission."

Behind closed doors is a world that the average archives visitor never sees - a vast world of metal and noise, where air and water is pumped through miles of pipes.

The central plant is where machines work to keep humidity and temperatures at ideal levels. In it sit five large machines called "chillers" that cool air and funnel it through the building. Only on the hottest days to do they all run at once.

"Our primary mission is heating, air conditioning and humidification," says Mr. Kahl, who oversees a staff of 79 workers trained in a variety of skills including electrical engineering, plumbing and welding.

It's a tough mission. Each room of records has specific requirements for humidity and temperature. For instance, the Nixon presidential room, which houses the text and records from the Richard M. Nixon's presidency, must remain between 63 and 67 degrees, with a relative humidity between 32 percent and 38 percent. A room housing color motion pictures is kept between 22 and 27 degrees, with a relative humidity between 27 percent and 33 percent.

Mr. Kahl, 58, knows the importance of his work. A retired Air Force veteran, he has worked at the National Maritime Intelligence Center and, before that, as a coordinator on NASA's space shuttle.

The archives building was designed to keep records in areas where temperature and humidity could be controlled easily. …