Building renovation gives valuable artifacts a new home
Smithsonian museums get an award-winning climate-controlled facility for their extensive collections.
One of the most memorable cinematic images of the last three decades is the final scene of Raiders of the Lost Ark, where the crate containing the Ark of the Covenant is wheeled through a giant warehouse containing countless other such crates. While, as far as I know, the federal government doesn’t have the warehouse depicted in that film, the next best thing may be the Smithsonian’s Pennsy Collections and Support Center, an unmarked 360,000-sq-ft warehouse in Landover, Md. There one can find rows of 20-ft-high shelving containing every imaginable type of artifact.
The building holds an extensive textile collection; floor-to-ceiling racks filled with 18th-century pianos; and historic films, photos, and documents. Unlike the movie warehouse, however, this is not a dusty, breezy place, but one with strict environmental controls to preserve all the treasures it contains. Given the variety of items to be preserved and types of workspaces, the building has different climate zones served by 29 rooftop air handlers and a Meefog system providing precise levels of humidification to 15 of those AHUs.
On the fast track
When the leases for storage facilities being used by four of its museums were running out, the Smithsonian decided to look for a larger facility to consolidate those operations. In addition to being large enough, the building had to be close to downtown Washington, D.C., have easy access to transportation, and be able to service large trucks for loading and unloading. After looking at many different buildings, the Smithsonian settled on a 1960s furniture warehouse in an industrial area of Landover, Md. It met the Smithsonian’s size, location, and loading needs, but was in no shape for preserving valuable artifacts.
As part of a 15-year lease agreement, however, the building owner, Trammel Crow, agreed to pay for the necessary build out. It hired the architecture firm Gensler to oversee the renovation, and Gensler contracted with Vanderweil Engineers as the primary MEP engineers. Both groups had to operate on a compressed time schedule.
“It was fast track,” said Deb Hill, project manager for Gensler, the architecture firm overseeing the renovation. “We were dealing with seven different entities, so there were a lot of people weighing in, and they had to move.”
The building was laid out with a mix of dedicated storage spaces for some of the museums, combined with shared spaces including a cafeteria, fitness center, library, showers, workshops, and print shops for creating the signs and materials for exhibits. It also included facilities for training Smithsonian security personnel, such as xray equipement and a simulated gun range, and a central mail facility for the institution. The storage facilies needed cusom built shelving, and archival spaces had to be divided into smaller sections for fire protection. The team established 12-ft-wide routes for vehicles to move through the warehouse and separate smaller paths for people. An emergency generator was installed to power life and fire safety systems in the event of a blackout. Water sprinkler systems not only had to be installed along the ceiling, but also within many of the shelving units.
To top it all off, everything had to look good. And the end result does, with the facility winning several design awards, including an American Insitute of Architects (AIA) Maryland Honor Award for Interior Architecture.
Controlling the environment
One of the team’s major challenges was creating a workable environmental control system for the building. Most buildings are designed for a limited range of climate zones. In this case there were offices, a café, meeting rooms, and workshops, but those just needed to be kept comfortable for humans. In the building’s archival areas, it was a different story. Most of the areas didn’t require any extreme temperatures or humidity levels, though one section did have to be kept at 52 F and another at 26 F. But even in the rest of the warehouse the temperature and humidity must be tightly controlled. For example, the permitted humidity range is far narrower than that allowed under AHRAE 55-2010: Thermal Environmental Conditions for Human Occupancy. Instead of allowing up to 80% humidity with no minimum, the Smithsonian required humidity to be kept at 50% +/- 5% year round. This wasn’t for human comfort, but to protect the artifacts.
“The majority of the warehouse is one climate zone, with a standard humidity and temperature we dictate for the collections,” said Evi Oehler, project manager for the Pennsy Collections. “We have to avoid wide swings in the humidity. If it swings up and down, the materials will expand and contract, damaging the artifacts.”
Maintaining the humidity levels constant in all areas eliminated the risk of higher or lower humidity air leaking from one collection area into another. In some areas, however, the air did need to be kept separate. For example, some of the shops had dust collection systems that vented to outside collectors. Others had paint booths or soldering areas with Nederman snorkel exhaust units to remove the fumes. Some specialized labs required once-through air systems.
“There were a lot of specialized areas, each with its own climate control,” said Don Posson, managing principal engineer from Vanderweil for the project. “We really wanted to keep the climate zones separated so there wouldn’t be any cross contamination.”
The library and rare book collections also needed their own climate control. In this case, Posson said the system had to be in accordance with the National Archives and Records Administration’s policy directive covering Archival Storage Standards (NARA 1571). Among the Section 1571.8 requirements:
- Archives storage areas, processing areas, and preservation laboratories must be served from separate HVAC systems.
- The records storage areas of the facility must be kept under positive air pressure especially in the areas adjacent to the loading dock.
- Areas where records are used, processed, stored, or exhibited must be isolated from sources of pollutants and particulates, such as the loading dock, machine rooms, or areas where woodworking or painting take place.
Section 1571.9 covered the temperature and humidity, restricted daily temperature fluctuations to 5 F and/or 5% relative humidity. Paper records and most other artifacts have a maximum dry bulb temperature of 65 F, while some photographic media need to be stored at 35 F and 35% RH +/- 5%. The paper records were allowed a broader humidity range of 35% to 45% +/- 5%, though the preference is to maintain it closer to the 35%.
While there were a large number of air handlers, the building was able to get away with a single humidification system. Initially the warehouse was going to use a boiler, but this would have been too costly. Instead, the team went with a high-pressure fog system from Mee Industries of Irwindale, Calif., which is cheaper to operate and easier to maintain.
“The Meefog system is more energy efficient, especially for a building that is getting humidification throughout the greater percentage of the year,” said Posson. “We originally were moving in the direction of a steam boiler system and steam injection, but the Smithsonian brought up that they were going to be spending a lot of money on utilities, so we looked at fog as an option to keep the operational cost down.”
This Meefog system built for the Pennsy warehouse uses a redundant pump skid to pressurize the water and sends it through 2400 ft of high-pressure stainless tubing to 15 separate duct-mounted stainless steel humidification chambers. The pump can provide up to 540 lbs. of water per hour to arrays of impaction pin nozzles within those humidification chambers. The water passes through a .006 in. orifice in the nozzle and then strikes the impaction pin, which splits the water stream into billions of minute droplets that rapidly evaporate in the airstream. Solenoid valves controlled by the building management system open or close as needed to control the water flow to the nozzles, providing the exact amount of humidification needed at that moment in time.
Constant growth
Although the schedule was tight, the team did get the job completed in time. Some tuning was needed on the air handling systems to control the air pressure differential between different zones and prevent cross contamination. The museums started moving their collections into the new facility in August before their existing leases expired that fall.
For now, the museums have a beautiful new space to store and restore their artifacts and ready them for display. But even though the place is huge, it won’t be big enough for long. Oehler is working with the different groups to maximize the space they have, but the warehouse is filling up.
“We don’t get rid of things and our needs grow constantly,” she said. “As we grow, we will fill this place up to the rafters.”
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