Fresh Approaches to New Needs

Continuous change in needs and technology are a constant part of building design and engineered systems. As new demands are dictated by building occupants, owners and government institutions, different approaches step in to fill the need. Simultaneously, developments in technology bring expectations of building-system performance to continuously higher levels.

By David Niemann, P.E., and Scott Clark, P.E., CEM, Carter & Burgess, Dallas, Texas June 1, 2001

Continuous change in needs and technology are a constant part of building design and engineered systems. As new demands are dictated by building occupants, owners and government institutions, different approaches step in to fill the need. Simultaneously, developments in technology bring expectations of building-system performance to continuously higher levels.

In the recent past, concerns over energy efficiency, indoor-air quality (IAQ) and climate control have pushed building-component vendors and system designers in new directions. High-tech facilities are demanding greater utility services. And a larger availability and refinement of ultrareliable power and control systems have brought these services beyond niche applications.

The latest HVAC leap

Over the past 10 years, heating, ventilating and air-conditioning (HVAC) technology has made a huge leap, mainly as developing technologies have combined with energy and environmental concerns. As a result, software and controls are now available that make HVAC system design much easier and more reliable. The most sophisticated of these systems actually sense conditions and determine the best way to handle them.

Control manufacturers are offering software packages that allow for more to be done within a building’s HVAC, mechanical and security systems. Some vendors have developed systems that can actually learn the cyclical patterns of building occupancies and operations. The systems in this mode look for trends and variables, deciding where to lock in for the best combination of building features.

The features allow building owners to customize their HVAC systems for energy efficiency and usage. For example, a facility’s operational staff could use a control package to program an early morning warm-up and economizer cycle to where outdoor air is brought in to do some of the conditioning.

Environmental influence

Environmental concerns have likely had more influence on HVAC technology than any other factors over the past decade. Air-quality and energy-efficiency standards enforced by the Environmental Protection Agency (EPA) and other jurisdictions have forced the development of some of these technologies, but concerned building owners have also helped lead the way.

HVAC manufacturers responded to the EPA by developing products that are more energy efficient, offer lower carbon-dioxide emissions and reduce ozone-depleting substances. In one example of environmental progress, EPA estimates show that 44 percent of the chlorofluorocarbon (CFC) chillers that existed in the country in the early 1990s have been replaced with non-CFC chillers.

Building owners have the ability to spur change by focusing their attention on creating a healthier workplace environment. Many of them have become aware of the “green building” concept, which keys in on renewable resources and recyclable materials.

Owners are also increasingly aware of the correlation between a healthy work environment and worker productivity. Indoor-air quality is now a big concern, and facility engineers are designing systems that bring in more outdoor air and make for a healthier workplace.

With regard to IAQ, a common trend for HVAC-system designers is to recommend a “bake-out” of a building before it is opened to occupants. In the bake-out cycle, the HVAC system is brought up to full heat capacity. The hot air helps to dissipate the odors and toxins released by new paint, carpet and other building materials.

Assuring reliability and security

Another growing challenge is the need for systems that guarantee “100-percent” reliability.

A host of telecommunications facilities, for example, need to be assured that the HVAC—along with other mechanical, electrical and plumbing systems—is virtually 100-percent reliable.

Providing on-site power is one way to ensure reliability. These buildings typically require two electrical feeds, 100-percent on-site electrical generation and, in addition, an uninterruptible-power supply. This way, the facility has several different ways to back up its power needs.

For the most part, the need for 100-percent power backup is for cooling services. Companies in a variety of industries need to assure that the temperature of their buildings remain at a constant level to assure optimum operation of their equipment. A common goal is to keep sensitive equipment in a constant environment of 68°F and 50-percent relative humidity. Constant cooling is needed because the equipment can generate as much as 100 watts of energy per square foot—a tremendous amount of heat. In fact, these companies often require no heating because their switching and telecom equipment generates all the heat they need.

Pharmaceutical and biotechnology labs also require these types of constant environments with tight temperature controls. They need systems with built-in validation features that prove the system is doing what it says it is doing. This is often the case for companies that are working on drug approvals and medical trials.

Utility companies throughout the nation are also looking to develop systems that are 100-percent reliable. Some utility companies are willing to put in command and control centers where they can link multiple sites together and dispatch and monitor from one site—which is a more efficient setup.

Security is another big issue for many building owners. Two buildings at the National Nuclear Security Administration’s Los Alamos National Laboratory in New Mexico provide a relevant example: both the Strategic Computing Complex and the Nonproliferation and International Security Center (NISC) required a high-level approach to reliability and security. The security design for the NISC was accomplished in collaboration with the U.S. Department of Energy to assure that the building had the proper security devices. Both buildings have functions that need to be operable around the clock, so to that end they now have redundant heating, cooling and generator power.

New demands, new solutions

New technologies have made it conceivable and cost-efficient for a wide range of facilities to meet new demands in the realms of energy efficiency, IAQ and occupant comfort—demands that were not prevalent even a decade ago.

Likewise, there was a time when 24×7 operations were of concern to few outside of government or hospital facilities. Today, 24×7 capabilities are required and expected by almost every kind of business under the sun.

Future Focus: Plant Designed for Explosive Growth

Like most large airports in the U.S., Dallas/Fort Worth International Airport (DFW) is experiencing growth that will require substantial expansion well into the 21st century, including building two new terminals and the extensions of three existing runways.

One of the key projects that will support this growth—and address a number of related needs—is the $122 million “central utilities plant systems” upgrades project.

“We will be achieving a substantial reduction in air emissions for the airport and the DFW region, while simultaneously positioning ourselves in advance of electric utility deregulation to reduce operating costs and enhance the reliability of service for our customers,” says Robert Barker, associate vice president for energy and utilities services at DFW.

The upgrade will also increase expansion capacity, reduce tenant costs, update existing infrastructure, enhance utility-plant flexibility and adaptability, as well as provide cost savings.

The project involves the potential development of a 110-megawatt on-site generation system with a base load capable of covering all airport loads plus export at ultimate build-out. The project also involves demolition of outdated equipment, new construction at existing facilities and the construction of a building to house the anticipated new equipment.

Underfloor Systems Get a Leg Up

Due to the churn rates caused by changing data-infrastructure needs, underfloor data and power systems are at last starting to become a popular choice in office-building and university-campus applications in the U.S.

Certainly, any building application where large, open indoor spaces—office space, convention centers, telecommunication hotels—need power, voice and data services, underfloor design gives the owner flexibility to reconfigure physical room layouts and easily upgrade services.

Additionally, underfloor-air systems have been shown to offer cost and performance advantages over traditional ceiling-delivery methods under certain conditions, especially where greater individual control over occupant comfort is an issue.

A recent project highlighting the benefits of underfloor systems was recently completed at the headquarters of Infonet, a global communications-services firm based in El Segundo, Calif.

The new, 156,000-square-foot facility houses office and telecommunications space that can accommodate up to 700 employees. The unique building features three stories assembled in a “T” configuration divided by a formal staircase, elevators and a two-story lobby. This elaborate layout did not necessarily enhance the company’s ability to provide services to all of its occupants.

Additionally, when creating their home facility, the leaders of Infonet recognized the importance of flexibility for future growth.

Due to the requirement for flexibility and elaborate layout, underfloor access systems were decided upon to distribute power, voice, data and conditioned air.

Infonet can now reconfigure their building in a matter of hours rather than days, and can perform the work without the aid of outside maintenance contractors.

Additionally, the underfloor access system requires less energy to operate the mechanical systems. Plus, the steel understructure for the raised floor is designed to meet all seismic code requirements.

To learn more about the underfloor systems used in this project, circle 100 on the Reader Service Card, page 49.