From motor control centers in bustling industrial hubs to remote communications equipment on mountaintops, integrated control houses are popping up just about everywhere. Containing increasingly critical and sensitive electronic equipment, control houses are often integral to our sprawling commercial and public infrastructures, including utilities, communications, defense, research, and manufacturing.
Once dubbed a "tin shack," today's control houses have far more sophisticated requirements than their predecessors, including not only security and protection from the elements but also climate control, fire protection, backup power systems, communications, and event recording for a wide range of ever-changing applications.
Obtaining all those capabilities in a durable yet practical structure can be a challenge. In some cases, engineers have gone to extremes in designing control buildings from "scratch," insisting on block-and-mortar or pre-cast concrete structures that are expensive, time-consuming, and difficult to transport.
Transportability is often a key issue for a number of reasons. Pre-cast concrete structures must be hauled on big-rig flatbeds, which are both expensive and very cumbersome over long distances. Remote locations, such as rural areas and mountaintops -- where transmitters, substations, and communications systems might be located -- can be difficult if not impossible to access due to narrow and unpaved roads. Special roadway clearance permits may be required, and secondary vehicles may be needed to lead and follow wide loads. Once a pre-cast concrete house has been trucked to a remote location, large cranes are required to unload and position the structure.
Prefabricated or "manufactured" buildings, cousins of the double-wide house and temporary classroom, share many of the same transportability problems as pre-cast concrete buildings. After they are fitted out with the control room equipment, manufactured buildings also have to be trucked to locations, sometimes to areas difficult to access. Once they arrive, they are offloaded and mounted on a slab.
The block-and-mortar or otherwise built-from-scratch control house also presents a number of transportability issues. Building materials have to be trucked to the construction site, which may have limited road access. Once the materials arrive, a staging area must be provided, plus a work area for the construction team. Forklifts and air compressors are often required. Depending on the building design, a range of construction trades may be involved, such as masons, carpenters, metal workers, and HVAC contractors. Once construction is complete, a team of technicians will be needed to install electronic equipment and hook up the control house.
A Modular Alternative
On the other hand, today's pre-engineered, modular panel steel control house offers an attractive, money-saving alternative.
"The modular steel control building represents a new school of thought among end-users and engineers," explains Ben Kurtz, business development manager with Kelly Klosure Systems, Fremont, NE, a specialist in pre-engineered panel steel buildings and interior enclosures.
"They believe that the technicians responsible for installing equipment inside a control building are also fully capable of putting the building up. With the right modular panel system, no particular construction skills or personnel are required -- and no special tools," adds Kurtz.
The pre-engineered, modular panel concept offers many important advantages over the other approaches: It is more economical, easier to implement, requires less time, minimizes manpower requirements, and can offer significant flexibility.
Modular panel buildings are constructed of mix-and-match panels, and are assembled on site. Because they are shipped as a kit, they are far more transportable than pre-cast concrete or traditional prefabricated buildings. When buildings are needed at remote locations, this can make a huge difference in transportation requirements, and even feasibility.
In the Kelly Klosure Small-Span building, structure, sheeting, and optional insulation are pre-installed in unique modular panels, as are doors, windows, and ventilation. Because the panels are pre-punched to accept patented locking keys, contractors can quickly attach hinged roof panels to wall panels with one hand.
Case Study: Valmont Wind Energy
"It is essential that the control houses we include with our wind turbine towers are containerized," says Mark Ringenberg, projects manager at Valmont Wind Energy, Valley, NE. "One of the primary benefits of our wind tower design -- and part of our mission statement -- is that the entire system is completely containerizable, including the control house that encloses the system controls."
Valmont's breakthrough wind turbine tower, for turbines in the 660 kW to 1.5 MW range, incorporates a utility-grade installation system designed to overcome the installation challenges of typical wind tower designs. Featuring a patented self-contained turbine lifting system, the Valmont structure is completely modular and composed of sections of manageable size, which brings with it several advantages, including expanded corrosion protection options and reduced shipping and construction costs. The entire Valmont structure, including the control house, can be erected without the use of large cranes.
"This modular design also gives us a transportation cost advantage," says Ringenberg. "Wind towers in general have sections 60-80 ft long, with base section diameters that are about 12-14 ft. That presents a shipping dilemma, because they're over-width, over-length and overweight for normal surface transportation. Their size also makes it tough to ship conventional towers overseas, where we intend to market from Nebraska. So, obviously, it is important for us to have the control houses as containerizable as the tower."
Valmont selected Kelly Klosure's "Small Span" modular steel building as a solution to its control house needs. Available in sizes 6-24 ft wide, with 3 ft modular panels to fit any length requirements, the Kelly Klosure product gave Valmont the needed ability to containerize, plus the utmost in flexibility and a lifespan of at least 30 years.
"Ease of installation is an important requirement for our control houses," says Ringenberg. "It is important that they can be assembled with standard tools and no special expertise. In the past we've had to cope with structures that required unique tools and assembly equipment, which prolonged the completion of the structure and made the work unnecessarily difficult."
Valmont is currently looking at sites ranging from the Galapagos Islands, where it is hot and humid, to Northern Canada, where it is freezing and dry, running the gamut of environmental extremes. "Our wind turbine towers are designed for use at a variety of locations, ranging from seaside to mountaintop," Ringenberg says. "Many could be exposed to harsh elements and extreme temperatures, so the durability of the steel control house is critical, as well as the integration of whatever ventilation and other climate control devices are appropriate for each installation."
The flexibility of modular panel steel control houses enables customers to minimize sizes, and thereby save on energy needed to power heating or air conditioning systems. These structures are also easily expandable, so that facilities that add equipment can enlarge their motor control centers easily, whenever required. An existing building can easily be enlarged simply by removing an endwall and attaching additional wall and roof panels.
Case Study: Jacobson Helgoth Consultants
Lengthy approval procedures and exorbitant construction costs can also be overcome with the modular steel control house design. Those were among the considerations when Jacobson Helgoth Consultants (JHC), an environmental consulting firm, engineered an ultraviolet (UV) disinfection project for the Wilber, NE wastewater treatment plant. For security and weather protection, key process control equipment had to be housed within a protective structure.
Conventional structures typically took months to complete, including up-front design and engineering, lengthy approval procedures, and labor-intensive construction requiring builders to erect a frame, drape insulation, attach sheeting with self-tapping screws, then frame doors, windows, and ventilation.
"We couldn't wait months for a structure to be manufactured," said Fred Scarpello, project manager in charge of the project for JHC. "We didn't want a little metal shed unable to support lighting, ventilation, windows, or skylights. And we didn't want to buy a structure that was too large, that required over-building the foundation to fit the structure. To minimize cost, we wanted to minimize the foundation and then fit the building to that."
At the recommendation of a professional colleague, Scarpello turned to Kelly Klosure Systems. "The pre-engineered system saved up-front design and engineering time, and the building's one-day erection time helped speed project completion and saved a significant amount in construction costs," says Scarpello.
Kelly Klosure's Small-Span design, to specified 18 x 8 x 22 ft dimensions, was pre-engineered to UBC (Uniform Building Code) for fast approval. It included a personnel door, three windows in one sidewall, fixed louvers in each endwall for ventilation, R-10 insulation, and 3 ft wide fiberglass skylights covering about 40% of the roof area for maximum daylight exposure.
The building was delivered within four weeks of order and erected in one day by a four-person contract crew. The industry average for erecting traditional structures, in contrast, typically takes up to 10 weeks.
"Kelly Klosure gave us the small footprint structure we wanted with all the features typically found in larger, more expensive traditional buildings," concludes Scarpello. "They also offered this in an aggressive timeframe at the right price."
Small-Span buildings meet the year 2000 International Building Code (IBC), and have standard clear span widths as narrow as 6 ft or as wide as 24 ft, lengths as short as 6 ft or as long as 99 ft, with standard heights from 8 to 14 ft. Kelly Klosure, through Kelly Industries, is a General Services Administration (GSA) authorized Federal Supply Service (FSS) contractor.
