National Renewable Energy Lab To Use Trapped Thermal Energy for Heating and Cooling

The Department of Energy’s National Renewable Energy Laboratory (NREL) is the nation's primary laboratory for renewable energy and energy efficiency research and development.

Their mission is to advance America’s energy goals and to help accelerate renewable energy research from innovation to marketable energy solutions. It’s a pretty cool place. (They also happen to be hiring. Did I mention that it’s in Golden, Colorado?) And next summer, it may be even cooler using thermal energy storage.

The architecture firm RNL Design has designed NREL’s Research Support Facilities (RSF) to be the first Zero Energy Building (ZEB) of its kind as “a national ‘showcase’ to demonstrate how high-performance buildings can be aesthetically compelling, acquired at a competitive first-cost and lifecycle cost, and through integrated design, how high-performance buildings can reduce performance risks to the Owner and constructor.”

One of the most unique features of the new building is a labyrinth in the basement to trap thermal energy and use it to warm or cool the offices above. The idea is to trap heat during the day and cool air at night and then slowly release that thermal energy when needed.

The way it works is that each wing of the building will be atop a low basement. The walls of the basement will be concrete and staggered so that air, which has traveled down ventilation shafts in the stairwells, must make turns, with the help of fans, and linger in the space forcing it to lose its cool or heat which will be absorbed into the concrete slabs. Fresh air the next day will be forced through the labyrinth, picking up some of that heat or chill to help warm or cool the building.

Heat from the sun will be channeled through a transpired air collector(pdf) made from metal sheets with tiny holes, a concept which won NREL an award in 2004. The building will also use heat drawn from the computers in the data center, turning otherwise wasted heat into a useful energy source.

The engineering firm, Stantec, which developed the labyrinth, used a computer program to optimize the size and shape and to calculate air flow. Because it’s being built for NREL, the technology is meant to be shared in order to help others design more efficient buildings using similar technologies.

Moving air through the cement slab basement won’t cool or warm it completely. But it will change the temperature by 5 or 10 degrees, enough to provide significant savings on energy use over the long term. In fact, they expect that the building will use up to 50% less energy than other office buildings.

The building is expected to be completed in summer of 2010 and developers are planning on the RSF receiving a Leadership in Environmental and Energy Design (LEED) Platinum designation, the highest possible.