Thursday, June 9, 2011

IKEA’s Coefficient of Firsts...

Centennial’s new store offers a technological marvel in its geothermal HVAC system.
By Karl Emmerich

I felt more like a tourist as I stepped back with my camera, trying to capture the breadth of a 415,000 square foot building that could house two other retail stores inside it (four, if you include the two levels of parking). But I was determined to make my 55mm lens as wide-angle as possible. I finally snapped the shutter just feet from a stop sign across the road.

IKEA is about firsts this July 27th as it opens its doors in the Denver-area suburb of Centennial, marking its first store in Colorado along with a first-ever in the United States commercial HVAC system of this size and efficiency. But to offer just a couple more premiers, the big blue store in Centennial features two more efficiency twists to its enviable geothermal system: a radiant heat rejection system and thermal storage ice tanks serviced by Bosch’s newest commercial model, “Aquarius WW420” water-to-water high efficiency heat pumps.

If this sounds like a lot of fantasy, it was, until one fortuitous call was placed by the IKEA U.S. Energy Manager, Mark Gasper, to the geothermal energy design firm, Geothermal Systems of Colorado, LLC (GeoSysco). Fortuitous, indeed, for both firms, as what seemed like a casual interest at the far side of GeoSysco’s phone line turned into a 415,000 square foot opportunity in the months that followed.

In the words of GeoSysco’s Executive Manager of Operations, Andrew Schmeising, “it was a chance to not only take on a major project, but to innovate and do something really special…”

And as for the innovation? GeoSysco imagined a first-in-the-U.S. opportunity to model the traditional commercial heat rejection towers into a more Colorado-practical alternative—40,000 square feet of horizontal radiant slabs that would displace more than enough excess heat year-around to cool the building properly, and also provide a secondary snow melting benefit to give IKEA a maintenance-free customer delivery area in the winter. Instead of dissipating excess heat vertically into the air where it would be wasted, GeoSysco designed a way to recycle the heat into the added benefit of not having to plow snow or melt ice in the parking lots and driveways on the north side of the Centennial IKEA store, not to mention the elimination of maintenance costs associated with cooling towers and the damage caused by commercial ice melting salts.

Back to the Future. IKEA’s Centennial store is built literally atop the ground heat exchange system that extends vertically beneath the building and throughout the entire area of the parking garage. Its “wet side” consists of 130 geothermal “loops” that extend 500 feet into the sub-surface, which are then manifolded together in the lower parking deck mechanical room where the primary heat pumps are located. Incorporation of the radiant heat dissipation slabs and the thermal ice storage allow the ground heat exchanger to be smaller and less costly than otherwise would have been the case.

From the mechanical room, the rest of the building’s heating and cooling needs are addressed, including hot water, cooling for the building’s elevator shafts, control room, and all the walk-in coolers for the in-store restaurant, in addition to the external radiant heat dissipation slabs, and nine vertical water storage tanks that comprise the “passive cold storage system.” This ‘cold reservoir’ of sorts, uses a bevy of water for the purposes of creating ice during off-peak electrical rates. The ice supplements the main ground heat exchanger during peak demand to cool the IKEA customers inside during the scorching heat of Colorado’s summer.

On Efficiency. As a first note, the massive IKEA geothermal system is 100% hydronic, devoid of any gas line. And unlike conventional electric HVAC systems, this masterpiece doesn’t lose efficiency during peak summer hours nor does it peak in performance. In fact, with each higher degree climb, the Bosch system maintains an even flow of electrical efficiency. The Energy Efficiency Rating (EER) and Coefficient of Performance (COP) of this system are not publicly available, but are among the highest in the industry and remain constant regardless of weather extremes. The added benefit for not having to shovel snow or add ice melt is simply best described as the standard of things to come for other large scale geothermal commercial systems.

For a firm whose contact began with a cold call inquiry, the massive geothermal system’s construction seems to be more of a marvel. But in the words of Geothermal Systems of Colorado’s Executive Manager of Operations, Andrew Schmeising, it holds just two consummate distinctions: “the most sophisticated” and “the most efficient”.

But then again, isn’t that just IKEA?

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