Hpac 701 Bse Air Force Steve Bothell

High-Performance Circulator System Takes Flight at Air Force Base

Jan. 1, 2012
New technology reduces control and balancing valves

Joint Base Elmendorf Richardson (JBER), near Anchorage, Alaska, is home to the United States Air Force's 3rd Wing. The unit, which is ready to deploy at a moment’s notice, includes F-22 Raptors—the world's most advanced stealth fighter aircraft.

Before the Air Force's elite pilots get actual air time in a Raptor, they must undergo hundreds of hours of classroom instruction and training specific to that aircraft. The pilots receive final training at JBER's newly constructed F-22 flight-simulator-facility.

The 23,000-sq-ft facility is one of two new buildings on the base. The other is the new professional-military-education (PME) center. The PME houses classrooms and training areas for non-commissioned officers.

High-Flying Heat
Average January temperature at JBER is 15°F, with lows dipping below -20°F. Like most heating systems in a state that takes the need for mid-winter heat seriously, the hydronic systems at JBER were built with high performance in mind.

"Our design temperature for both buildings is -20°F," said Steve Nazaroff, mechanical division manager, Weldin Construction. The Palmer, Alaska-based company built both facilities at JBER and installed all of the heating systems’ components.

"The design on the buildings started in 2008," Nazaroff said. "It was challenging to get the government to accept the plans for a heating system they'd never seen before."

Weldin finally received approval to install Taco LoadMatch systems.

LoadMatch utilizes maintenance-free wet-rotor circulators to complement two common systems: single-pipe distribution and primary-secondary pumping. The primary distribution system is a single-pipe loop; the secondary distribution system is a decoupled secondary-piping loop for each unit in the system.

The LoadMatch system replaces all the control valves and most balancing valves found in a traditional hydronic system with small, low-killowatt circulators. The circulators deliver the water where it needs to go instead of forcing it where it is not needed, resulting in savings in raw materials, installation, and energy consumption.

"The system is self-balancing, reducing many start-up, commissioning, and operational problems, because all zones get their required amount of flow at all times," Nazaroff said.

In addition to energy savings and efficient heat distribution, LoadMatch reduces head loss by eliminating many control and balancing valves and a considerable amount of pipe. The result is lower pump head and less energy consumption to move the water.

In both buildings at JBER, heat travels through a heavily insulated, three-in. main mounted in mechanical mezzanines. With the aid of the LoadMatch circulators, the main supplies variable-air-volume (VAV) boxes, baseboard, and single-fan-coil units through 3/4 or 1-in. secondary piping.

"Installing only one main line, as opposed to a separate supply and return, saves copper, and lots of time," Nazaroff said.

At the Source
Two 800-MBH gas-fired boilers are the Btu source for the F-22 flight-simulator facility. From the boilers, water travels through the 3-in. main into the building. At most of the terminal units, 3/4-in. lines tee off.

JBEF has two simulator bays that are 60 ft long, 25 ft wide, and 27 ft high. Overhead doors seal each bay. Inside is a mechanical and electrical marvel: a Boeing F-22 flight simulator positioned on hydraulic stilts that allows the pilot to experience maneuvers like real flight. The VAV boxes and the units in the simulator bay are supplied by 1-in. lines.

At the PME, two 872-MBH boilers heat the building in the same way. Lacking the large simulator bays, the building's entry-area units are the only ones that require one-inch lines.

Domestic water for the facility is heated with an electric, 80-gal. 99.1 percent thermal efficiency-rated Laars eF water heater.

The buildings were insulated with R19 batting in the walls and R30 rigid insulation in the roof. The exceptions are the simulator bays, where R22-insulated metal panels were used to form the walls.

The Computer Load
Although Alaskan summers can get a little humid, uncomfortably hot conditions are rare. June of 1985 saw a record-setting high of 85°F, but the summer average is 56°F. The cooling systems' design temperature is 70°F, which seems insignificant, but the real load on the chiller and air conditioners comes from the heavy computer infrastructure found inside the buildings.

"There's a multistack, 60-ton chiller at the simulator building piped to large cooling coils that provide space cooling," Nazaroff explained. "Communication and server rooms have additional cooling provided by Liebert computer-room cooling units. These are also piped to the chiller."

Erasing Bad Memories
"Although the LoadMatch system was the main reason we were able to finish the projects on time, in the beginning it was a real uphill battle with government officials getting the system approved," Nazaroff said. "Apparently, there's a nightmarish story about a single-pipe system at JBER that another contractor installed 20 years ago."

After being re-assured by Greg Cunniff, application engineering manager at Taco, that the failed system of 20 years ago was a completely different design, the project moved forward with LoadMatch.

"I'll use LoadMatch wherever I can," Nazaroff said. "It's better for the customer, better for the contractor, and in the end it means fewer headaches for me. The PME has been operational for more than one year now, and we haven’t had a single callback or comfort complaint."

Dan Vastyan is account manager for Common Ground, a trade-communications firm based in Manheim, Pa.