Hidden Treasure

There was a time in this country when many people thought drop ceilings were a modern architectural marvel. It meant a then-rare, but highly desired technology—air conditioning—could be added to an old building. Such was the case with the Federal Courthouse in Cleveland, a turn-of-the-century Beaux Arts structure that saw the addition of AC in the late 1960s.


There was a time in this country when many people thought drop ceilings were a modern architectural marvel. It meant a then-rare, but highly desired technology—air conditioning—could be added to an old building. Such was the case with the Federal Courthouse in Cleveland, a turn-of-the-century Beaux Arts structure that saw the addition of AC in the late 1960s. Being a time when classic features like coffered ceilings weren't as valued as cool, comfortable working conditions, these nearly extinct, artisan-crafted architectural elements were covered up to create AC plenums in hallways and elsewhere.

And like its elaborate plaster ceilings, the landmark building itself—originally the city's post office—went out of style and its function ceased to make sense in the eyes of federal operators. Just a few years after renaming the building for Ohio Senator Howard M. Metzenbaum in 1997, they shuttered it with the opening of the city's new federal courthouse in 2002. But like the historic Cleveland Arcade across the street, which now serves as a lobby for the city's downtown Hyatt, the Metzenbaum is about to get a new lease on life as a bankruptcy court.

The 235,600-sq.-ft. building is currently in the final construction phase of a $44.6 million modernization and renovation slated for completion this summer—its 100th anniversary. According to Paul E. Westlake, Jr., FAIA, the managing principal of the project's A/E, Westlake Reed Leskosky (WRL), the General Services Administration— through its Design Excellence, Fine Arts and First Impressions programs—is adapting and renovating the building to meet requirements for function, efficiency, accessibility, sustainability and security. "At the same time, priority is given to respecting the historic character of the structure and to celebrating the original values and presence of the federal government in our cities," says Westlake.

High I[A]Q

Ironically enough, the same kind of guys who enabled the shrouding of those valued ornamental elements—M/E engineers—are now the ones responsible for making sure these features are preserved for another generation. That said, they're still on the hook for providing AC and for making sure that the building meets current life-safety and energy-efficiency standards—but in an unobtrusive way that also meets LEED silver criteria.

As if that wasn't enough, an important discovery in the midst of building research made the need for an optimal internal environment even more critical: GSA wanted to return to the building a set of displaced—at one time, lost—murals by 19th century American artist Frank Millet. For those unfamiliar with the artist, his paintings hang in the Metropolitan Museum of Art in New York as well as the Tate in London. In this case, he painted a series of murals depicting postal delivery around the world. But like the final scene of Raiders of the Lost Ark , his paintings were crated up during the mechanical renovation in the '60s, put into storage and then forgotten for another 20 years.

The murals were found in the '80s, but remained in storage, according to Janet Opaskar, a property manager for GSA's Cleveland Service Center, as the agency simply didn't have the money to restore them. But with the Metzenbaum's renovation, funds were found, and the murals will eventually be on display in the main lobby. "And that was good, because the post office wanted them back," jokes Opaskar.

To Matt Murphy, WRL's mechanical engineer on the project, one thing was perfectly clear given the combination of rare murals, LEED goals and antiquated doors and millwork: a need for humidification. More obscure was the solution for the environment as a whole, as air conditioning, the desire for good IAQ, energy efficiency and capitalization of available resources all had to be factored. Furthermore, it was not only a question of how, but what HVAC equipment and where to put it.

"There used to be tons of AHUs in the building, but that weren't very cost-effective and was difficult to maintain," says Murphy.

Even if it weren't the case, significant asbestos issues in the former mechanical mezzanine ruled out the option of using that space for new AHU equipment.

The courthouse's programmatic requirements also added to the task. In order to meet proper circulation and security needs of a modern justice facility, the building would have to undergo some reconstructive surgery. Specifically, a central light well was converted to an enclosed atrium. Mezzanines would also be constructed to create gathering areas outside of new second-floor courtrooms, further limiting placement options. Fortunately, the building was about to yield more treasure, granted it was gold only in the eyes of M/E problem solvers like Murphy and fellow engineer Bob Smolinski.

"We discovered a lot of neat places that proved very useful for mechanical placement and other solutions," says Murphy.

For example, old chimneys became pipe chases and risers for electrical and telecom cabling. One even became a much-needed shaft for the building's new Eco Disc elevator that allowed the team to meet the security criteria of separate circulation of the public and court staff.

As Pittsburgh-based general contractor Dick Corp. began to gut parts of the building, demolition helped that process significantly. "That revealed a lot about the building," adds Smolinski, the project's electrical engineer.

But in the case of the problem at hand—HVAC—the solution was simply a matter of going to the top. In their exploration of the building, which consists of five floors, a basement and an attic, the latter ended up becoming Murphy's inspiration and ultimately, his favorite spot, at least according to Steve Thompson, Dick Corp.'s project superintendent.

Because it allowed access to four existing shafts in each section of the building, Murphy decided it was practical to zone the building into quarters using four 50,000-cfm units that were custom-built to fit in the tight space. These big units, however, raised GSA's eyebrows, particularly because of its LEED energy efficiency goals and its own best practices. What sold GSA's chief architect and engineer, who reviewed all the M/E plans, was the fact that the big units would rarely operate at peak volume. "Each AHU is essentially two units in one, with separate lead and lag fans, cooling coils, heating coils and humidification systems," says Murphy. This two-stage design, he explains, allows supply-air capacity to better match the building's cooling loads, which will fluctuate greatly as a result of the widely varying occupancy in different areas of the building.

Getting back to the issue of humidification, space conditions are set within 30% to 55% relative humidity (RH) on a year-round basis. This accomplishes three goals, according to Murphy: 1) it creates acceptable space conditioning for the artwork; 2) it creates the proper environment for the building's existing and new millwork; and 3) it allows the team to meet LEED Indoor Environmental Quality Credit 7 for Thermal Comfort for Building Occupants.

In addition, air distribution for this area is designed to prevent unmixed supply air at 90% to 95% RH from coming into contact with the Millet paintings.

As part of the goal of maximizing existing resources, humidity is generated by steam from a local district plant (as is chilled water for cooling). The M/E/P team further optimized energy savings by reclaiming heat from the condensate. Typically in district steam heating scenarios, Murphy says, condensate is wasted and discharged to the sewer system, with the double penalty of requiring domestic water to cool it to acceptable temperatures. "However, as part of the sustainable designs for the Metzenbaum, steam condensate [at approximately 200°F to 230°F] is used to pre-heat domestic water," he says. "So for much of the year, the load will be more than adequate to handle the maximum domestic water-heating load, representing a significant heat-recovery and operational savings."

As stated earlier, energy efficiency was, of course, a major GSA goal throughout. Beyond WRL's two-stage approach to the air handlers, supply fans are operated by variable-frequency drives to closely match supply air to cooling load and minimize fan energy consumption. And as far as systems control, the ventilation rate for outside air is varied directly as a function of CO 2 levels, and indirectly as a function of occupancy. "The application to the Metzenbaum Courthouse is appropriate because use of its courtrooms rarely draws full occupancy and will therefore rarely require the full ventilation rate," says Murphy. "By turning down the ventilation rate to match IAQ levels, as detected by CO 2 sensors in the space, significant operating savings are achieved."

The building automation system is based on LonMark technology, a path Murphy notes many GSA offices in the Midwest are following due to concerns about reissuing bidding packages. Oddly enough, the system operates on a Johnson Controls network—something JCI's Terry Hoffman doesn't find so strange. "There's definitely a problem with people feeling that some things are proprietary and that they'll get stuck with one vendor. This is especially true for people or agencies, like GSA, who want to be able to use other manufacturer's controllers in the field, particularly LonMark in this case."

JCI's new N2 system, in this instance, explains Hoffman, acts purely as the supervisory network, allowing the use of whatever controllers the client desired.

Treasure hunt continues

While much of Murphy's treasure hunt took him to secret spaces, lower-hanging fruit was available for his electrical counterpart Smolinksi to pick. Most notable were the ornate chandeliers in the main lobby, as well as other historic sconces and fixtures. That said, Smolinski's job was not cut and dried. He had to figure how to make these early 20th century fixtures perform to 21st century expectations. One thing that came through crystal clear was that old and new can co-exist famously. For example, the historic main lobby chandeliers are being completely refurbished and restored to their original condition. In lieu of incandescent lamps, compact-fluorescent globe lamps are being installed to provide increased light levels to the space.

Lighting within the lobby, as well as the new corridor that connects the lobby to the atrium (see photo at left), is achieved through the use of two different lamp sources: In the center of the space, chain-mounted, period-style luminaires provide general ambient and soft accent lighting for the paintings. To generate the required ambient light levels at the floor level, and minimize the cavern effect of the lobby's high-ceiling space, wall-mounted indirect sconces using metal-halide lamp sources with asymmetric reflectors are located above the paintings to reflect light off the ceiling.

The new connecting corridor on the first floor is illuminated with continuous, indirect fluorescent cove luminaires equipped with specular, asymmetric, adjustable reflectors installed along the perimeter walls. This arrangement, explains Smolinksi, reflects light off the ceiling and onto the walls and floor, providing the required ambient light levels for pedestrians traveling through the space leading into the atrium.

In addition, adjustable and dimmable, small-aperture, low-voltage, low-brightness, incandescent wall wash/downlights are located within the barrel-vaulted ceiling, providing superior beam control and performance. These luminaires are aimed in a crossing fashion to softly illuminate paintings on opposing walls.

But this is where the "old" ends and the new begins. On the other end of the innovation spectrum, a building-wide, web-based digital automation system is employed to integrate lighting in all occupied spaces. According to Smolinski, the system can be fully controlled and managed from a single location and allows for real-time monitoring and measurement of loads and load shedding for a multi-task office environment.

This is the first time he has worked with this particular system. Features that interested Smolinski include the web-based software that allows the system to integrate with and augment the building's temperature control system; automated on/off light switching and full-range dimming capability; and the ability to activate selected fixtures to meet code required foot-candles during a power failure.

"The new automated system provides an alternative to code-required, dedicated raceways for emergency circuits," says the electrical engineer.

All corridor luminaires are connected to emergency circuits to utilize the existing embedded raceway system. However, in the event utility power is lost, he says, the controls disable only the luminaires not required for emergency egress lighting, leaving generator sizing unaffected and avoiding additional construction costs.

Power upgrade

Speaking of power, the building's electrical-distribution system was converted from a 208/120-volt system to a 480/277-volt system.

"Because a given conductor can carry more than twice the load at 480 volts than at 208 volts, the savings for feeders of moderate length are quite significant," says Smolinski.

The change, he says, was also economically advantageous in that not only were savings accrued by using less wire, but also by the selection of service-entrance switchgear and utilization equipment. "The smaller current, at 480 volts, for any given rating of supply transformer capacity, permits using protective devices with smaller frame size and interrupting rating—both of which result in significant savings," says Smolinski.

From a lighting perspective, he says the new electrical system greatly minimizes the quantity of branch circuits, as most lighting now utilizes 277-volt branch circuits.

When it came to providing emergency power for emergency lighting, the team also took a different tack. Tritium-gas-filled LED exit signs were installed throughout.

These "self-luminous" signs, according to Smolinski, don't require electric wiring—a major advantage in an historic setting—and are being installed in greater numbers in both public and private buildings.

"A self-luminous sign remains lighted continuously, though you won't detect any illumination during daylight hours or in brightly lit rooms. In addition, self-luminous signs will maintain their illumination day-in, day-out, for up to 20 years," he says.

As far as emergency power, a 1,000-kW diesel generator serves the facility. The team opted for a diesel unit to ensure a higher level of reliability with lower maintenance requirements than the previous battery-operated emergency power system and lighting units.

That said, they did have to make special provisions for the unit. First, the generator is water-cooled, as opposed to employing a roof-mounted radiator. The team did this, once again, to take advantage of the existing district cooling plant. Fuel supply was another issue and was resolved by locating the tank remotely in an adjacent parking garage so it can be refueled with the truck not having enter the building proper.

Through rain and sleet and snow...

True to its original function as a post office, the renovated Metzenbaum delivers. Not only does it bring back to life an historic city landmark, it adds vitality to the regeneration of Cleveland's downtown. And with the display of the Millet murals, the building also offers an opportunity for locals—and maybe even some tourists—a chance to see great art and bygone architecture that's within strolling distance of the modern-style Rock and Roll Hall of Fame or even Cleveland Browns Stadium.

Millet, also an international traveler and war correspondent, lost his life after giving up his seat on a lifeboat of the Titanic. But with the Metzenbaum's rebirth, it's appropriate karma that his art has resurfaced, and hopefully, will live on to inspire others.

Fire/Life Safety

Of course, the story of retelling the challenges of retrofitting an historic building cannot be complete without addressing sprinklers. Installation of sprinklers in the foyer and the two historic courtrooms were a notable challenge, particularly on the aesthetic front. And even though the tenants didn't want them, GSA maintained a firm hand. "We're not following local code, but GSA guidelines and the BOCA National Code," says Dan Allen with DLA Specialists, the project's fire-protection design-builder.

Fortunately, when it came to the historic courtrooms, the team discovered a crawl space above the ceilings that allowed for piping and other M/E system runs. The recessed sprinkler caps were also painted to match the ornate ceilings. Besides a new fire-alarm system, the addition of the new central atrium also allowed for the inclusion of two sorely needed egress stairwells.

No comments
Consulting-Specifying Engineer's Product of the Year (POY) contest is the premier award for new products in the HVAC, fire, electrical, and...
Consulting-Specifying Engineer magazine is dedicated to encouraging and recognizing the most talented young individuals...
The MEP Giants program lists the top mechanical, electrical, plumbing, and fire protection engineering firms in the United States.
Commissioning lighting control systems; 2016 Commissioning Giants; Design high-efficiency hot water systems for hospitals; Evaluating condensation and condensate
Solving HVAC challenges; Thermal comfort criteria; Liquid-immersion cooling; Specifying VRF systems; 2016 Product of the Year winners
MEP Giants; MEP Annual Report; Mergers and acquisitions; Passive, active fire protection; LED retrofits; HVAC energy efficiency
Driving motor efficiency; Preventing Arc Flash in mission critical facilities; Integrating alternative power and existing electrical systems
Putting COPS into context; Designing medium-voltage electrical systems; Planning and designing resilient, efficient data centers; The nine steps of designing generator fuel systems
Designing generator systems; Using online commissioning tools; Selective coordination best practices
As brand protection manager for Eaton’s Electrical Sector, Tom Grace oversees counterfeit awareness...
Amara Rozgus is chief editor and content manager of Consulting-Specifier Engineer magazine.
IEEE power industry experts bring their combined experience in the electrical power industry...
Michael Heinsdorf, P.E., LEED AP, CDT is an Engineering Specification Writer at ARCOM MasterSpec.
click me