A 26,000-control-point UFAD at the IRS Kansas City Campus includes 3,800 in-floor VAV boxes and 300 fan-powered boxes to keep the air in a comfortable range of 60°F to 63°. A BMS integrates and controls the UFAD as well as a chilled water VFD pump control system, 32 AHUs, and 700 VAV boxes.

 The newly developed Internal Revenue Service (IRS) Kansas City Campus sits on 27.5 acres of land just south of the landmark Union Station and west of the Liberty Memorial. It is home to nearly 3,000 full-time employees and up to 5,000 seasonal workers, who are enjoying advanced indoor environmental and comfort control systems among other amenities.

U.S. Engineering Company and The Fagan Company, both headquartered in Kansas City, played key roles in the $370 million project that involved substantial renovation and new construction. Johnson Controls, Inc. worked with both companies to supply a 26,000-control-point Metasys® BMS and a YORK FlexSys™ underfloor air distribution (UFAD) system. The system incorporates an advanced design and serves more than half of the facility’s 1.14 million sq ft of office space.

Main street HVAC

Kansas City’s historic Main Post Office - originally opened in 1933 - anchors the northeast corner of the campus and serves as the administrative building. It is now called the Pershing Building. Stretched across the western portion of the complex are three massive processing wings, all connected through a “main street” circulation design. The processing side is referred to as the Pennway Complex and includes a parking garage with 3,800 spaces.

Plans for the project date to January 2000, when the IRS, the U.S. General Services Administration (GSA) and Jacobs Facilities, Inc. developed a vision for the optimal building configuration that the IRS would use for its new campuses. All the key components have a new design theme that acknowledges the IRS culture, visual aesthetics, and use of space in the years to come.

The GSA and the IRS selected Pershing Road Development Company, LLC, - a partnership of DST Realty and Premium Finance - to construct the build-to-suit complex using the Main Post Office. A key component to the IRS’ long-term business strategy was to have a modern facility that accommodates changes in workflow programs and technology. Thus, the processing wings were designed to be shut down individually for maximum flexibility and efficiency during non-peak hours.

BNIM and 360 Architecture designed the campus. The challenge for the design team was integrating a new 660,000-sq-ft addition onto the existing 475,000-sq-ft Main Post Office. Construction began in February 2004 and was completed in December 2006.

A BMS in control

The Metasys BMS from Johnson Controls integrates control and operation of the UFAD system, as well as a variety of other systems including a Systecon chilled water VFD pump control system; a Liebert Sitelink CRAC automation system; a power monitoring and switch gear systems; 32 AHUs; 700 VAV boxes (existing post office building), and a Vulcain addressable CO monitoring system (in the parking garage).

The system includes an advanced graphics package for easy monitoring and control of all systems on the network. The Metasys system’s BACnet field controllers provide continuous adaptive control so HVAC equipment “self-tunes” in response to seasonal changes and system dynamics, reducing commissioning time. Eliminating the need for manual intervention also ensures optimum equipment function, lowering operation costs, and maintenance and repair expenses.

All about flexibility

The UFAD was specified for the campus for a variety of reasons. First, GSA favors raised access floor design wherever possible in new facilities. UFAD is flexible and can be changed, as needed, to suit facility and personnel needs, and provides precise comfort control, with the ability to individually adjust airflow at each in-floor diffuser.

Further, DST Realty already had successful projects in the region. “Experience with underfloor air distribution was a ‘tremendous help’ in organizing manpower on the IRS project,” noted Mike Crabtree, project manager for The Fagan Company. “We finished on time and on budget.”

A central chiller plant provides cooling to the entire facility. In each of the three processing wings, six AHUs are positioned on a mezzanine level, pressuring the underfloor plenums on the floors above and below.

Some 500 zones are individually temperature-controlled. The UFAD system includes 3,800 in-floor VAV boxes and 300 fan-powered boxes. The terminal units in this second-generation FlexSys system employ an “air valve” that automatically modulates individual terminals to maintain thermostat setpoints closely.

YORK FlexSys systems operate at a low design pressure, which helps maintain airway integrity by minimizing air leakage. The system supplies air at 60°F to 63° for a comfortable and energy-efficient UFAD system.

“All parties including Johnson Controls and YORK were involved in the design process,” noted Justin Apprill, pre-construction manager for U.S. Engineering. “They answered all of our questions in determining whether or not the YORK Generation 2 system was the best system for this application. And, they showed us how the control system would be integrated.”