Engineer
VP & Technical Officer: Dale Holland, Dunham Associates
ED+C, July 2009
"Displacement ventilation mixes the supply air under the floor with room air about six inches above the floor," Holland said. "Then, the low-velocity, cool air rises over warm bodies and is displaced to air vents at ceiling level. In effect, natural convection instead of fan power drives the airflow and conserves energy in the process."
The selection of diffusers and Tate for access floors was also important to the success of the underfloor displacement ventilation system. according to Holland. "The diffusers we used throw air horizontally across the floor surface in a flat spin," Holland said. "As a result, air does not blow directly on people and comfort levels are maintained. We chose the Tate system, because Tate makes a good quality system."
The benefits of this unique HVAC system begin with energy savings directly attributed to the way the system operates. "An underfloor displacement ventilation system is very energy efficient because it requires very little energy to move air under the floor," Holland said. "Far less fan energy is required. And if we use displacement ventilation, we’re really only air-conditioning the occupied zone, which is the lower six feet of this high atrium building. So, we're saving energy by not air-conditioning a 40-foot high space. You combine that with the efficiency you gain with geothermal technology and you begin to see how all of these strategies work together to achieve super energy savings."
Electric utility leads by example: headquarters is Platinum LEED certified
Engineer: Dale Holland, PE, LEED AP and Executive Vice President of Mechanical, Dunham
Contractormag.com
"The displacement air system provides a pool of cool air only a few inches above the floor,” said Holland. “Because this air is cooler and therefore heavier than the room air it tends to stay at the floor elevation until it detects a rising plume of air from a heat source near the floor. When the heat source is provided, the cool air near the floor rises in the plume and cools the person or other heat source like a computer."
According to Great River Energy’s White Paper, this is one of the first times a geothermal heating and cooling system and under-floor displacement technology have been used together.
Clayco Builds Sustainable Headquarters For Novus
Engineer: Paul Todd Merrill, P.E., LEED AP, Clayco
Associated Construction Publications
"We think the building's Class A, high-technology, sustainable, environmental design represents the new standard in the industry," says Merrill. "Lighting requires less than half a watt a square foot — that is 75 percent less than you would find in structures we were building just five years ago. With the underflow air system, we are able to run the systems at lower volumes using less energy; and a new, high efficiency chiller plant supports the mechanical system."
Merrill says the state-of-the-art HVAC system allows the users to individually control workstation environmental conditions throughout the building.
High-Performance Building Systems: Mechanical, Electrical and Controls Systems, September 2008
Engineer:George P. Karidis, P.E., LEED AP, VP and Mechanical Engineering Discipline Director of SmithGroup, Detroit.
Building Design & Construction
"Primary UFAD advantages include greater individual comfort control, better indoor air quality, higher worker productivity, and less costly office/user churn."
Wiring Underfloor - Not Underfoot, Scott Siddens, July 2006
Engineer:Tim Koch, P.E., Electrical Project Engineer, HDR Inc.
www.csemag.com
"Raised-floor systems are of great benefit in medical facilities as well...Raised floors are common in radiology equipment rooms, such as CAT-scan and MRI rooms, which generally include new control cabinets in different room locations and new cables and routes."
"Distribution flexibility is definitely the greatest advantage. With raised-floor systems, the designer can locate an outlet anywhere on the raised floor and route any number of conductors to that outlet. When a client has a high churn rate, raised floor is really the only economical type of distribution."
Sustainable Contributions December 2003 - Phil Sheridan, Vice-President
Engineer: Carter & Burgess
www.architechweb.com
“…a raised floor system needs to provide circulation only at the level occupied by people. With a smaller volume of air to displace, the system requires less energy to achieve the same circulation rate…”
Future.....Perfect?
Engineer: Flack & Kurtz
Building Design & Construction Magazine October 1999 - Clark Bisel, Principal
“We have a big high-tech market,” Bisel says. “Their need for technical capability at the workstation, the flexibility of their work force and changing technological requirements are driving us to promote or go with raised-floor systems.”
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