With a name like the Michigan Alternative and Renewable Energy Center, you might expect the building to be a leader in resource-preserving or "sustainable" building.
So it may not be a surprise that the 3-year-old center, in Muskegon, Mich., is one of the first facilities in the state to achieve "gold" certification for new construction under the U.S. Green Building Council's Leadership in Energy and Environmental Design program.
The point-based LEED program awards credits to projects based on how efficiently they conserve water, energy, materials and other resources.
The 26,000-square-foot research facility, affiliated with Grand Valley State University, uses fuel cells, heat recovery for its HVAC system, solar power and nickel-hydride battery storage. The center was designed to produce all of its power needs.
Officials involved with the project say it is the first commercial project in the world to use all the technologies.
Finding a heating and air-conditioning system that would meet the building's needs and energy-conservation goals wasn't easy, said Lee Kaganovich with Mechanical Design Studio Inc. in Walnut Creek, Calif. Mechanical Design was the project's lead mechanical design firm.
The glass house"If you look at this facility's design, the biggest portion of the building is glass," Kaganovich said. "If you look at it from any direction, you can see inside. So, the structure has a huge heat-transfer surface. This kind of building always presents an HVAC challenge."
The design-build firm hired by the university, Grand Rapids, Mich.-based Workstage, decided to use the York FlexSys under-floor air-distribution system from Johnson Controls Inc. It purchased the equipment from Process Engineering and Equipment Co., also located in Grand Rapids.
"We try to put the York FlexSys system in every building we do," said Workstage project manager Ken Skinner. "We're sold on it. It performs well for us and has proven to be a substantial source of LEED points in those cases where our clients are seeking certification with the United States Green Building Council."
However, that wasn't what Kaganovich said he was hearing when Mechanical first started the project.
"Every engineer I talked to said I was getting myself into hot water," he recalled. "They were thinking about under-floor systems years ago that were nothing but trouble."
But that hasn't been his experience, at least not lately, Kaganovich said.
Flexible"Over the years, I collected and studied many articles on under-floor systems. After designing various UFAD applications and working closely with York application engineers, I now feel extremely positive about the UFAD system," he said.
The FlexSys portion of the project is fed by two York CurbPak air-handing units outside.
Kaganovich said the system's flexible design is a big plus.
"With a FlexSys under-floor system, it's substantially easier to accommodate last-minute changes by the architect," he said. "Adjustments are easy to make to the plans and in the field. Plus, due to the common supply airway configuration, there is plenty of redundancy in the system. Spare capacity in the system can be directed to a zone which is temporarily experiencing an unusual load."
Skinner from Workstage agreed.
"Our cooling solution is open to the entire plenum," he said. "Unlike first-generation constant-volume UFAD, barriers do not have to be added to create separate zones. Plus, we can use the same devices in the interior as we do for the perimeter. Heat coils can also be included in these versatile terminal devices, which, I must add, are extremely quiet and can be easily changed to accommodate individual comfort needs of the building occupants."
Since opening in 2003, the center has leased space to businesses specializing in energy efficiency and new technologies, such as solar and wind power.
Sidebar: How HVAC affected the center's ‘green' ratingUnder the U.S. Green Building Council's Leadership in Energy and Environmental Design program, structures can be listed as platinum, gold, silver and certified.
The more points a project receives, the higher the certification. To reach "gold," as the Michigan Alternative and Renewable Energy Center did, a project has to be awarded 39-51 points in categories such as sustainable sites, water efficiency, energy and atmosphere, innovation and design process, materials and resources, and indoor environmental quality.
Several points were due to the center's HVAC system. In the "energy and atmosphere" category, the center was given five points. It earned the points by exceeding the energy requirements of Standard 90.1 from the American Society of Heating, Refrigerating and Air-Conditioning Engineers. The standard deals with commercial buildings.
The mechanical system earned four points for being 35 percent more efficient than the standard's minimum requirements, York officials said. It also helped offset the higher temperatures produced by the building's glass-wall design.
"It's a trade-off," said Kaganovich said. "You can do a more efficient building. Or you can do a more efficient mechanical system. Or you can do a combination of the two to achieve your goal.
"LEED points are an abstract number, but each point represents real dollars - dollars to make the system work and dollars in energy savings."
Jack Geortner, FlexSys product and business development manager, explained how the under-floor system saved energy.
"You're going to see reductions in energy with an under-floor system - typically 10 to 30 percent," Geortner said. "That's because there is less fan-energy required, due to the system's low static pressure. Further, the air-distribution system is conditioning the first 6 feet of the space - or breathing zone - and not the entire volume of space, as is typical with an overhead VAV (variable-air-volume) system."
The energy center earned one point for using HFC-407C refrigerants in the HVAC system, which does not harm the Earth's ozone layer.
Under "indoor environmental quality," the center earned three points. One point was for monitoring carbon dioxide levels in the building. The FlexSys system works with sensors to check carbon dioxide levels in the center's second-floor offices and first-floor laboratories. The sensors let the system know when to add outside air to the building to make sure carbon dioxide levels never get above 530 parts per million.
The center's under-floor ventilation system, which brings air directly to occupants' "breathing zones," works better than traditional overhead air-distribution equipment, York officials said. Old, stale air rises as it is warmed and is removed through the ceiling.
System controls also earned the building a point in the air-quality category. Each floor-level FlexSys terminal is temperature regulated. Each has two grilles that nearby occupants can adjust to change airflow.
"You can sit on top of the terminal, and if you don't want to feel any air movement, you can adjust the grilles to blow air laterally instead of on your legs," Kaganovich said.
Other LEED points were awarded for commissioning and verification work, indoor pollution control and water savings.