Aldo Leopold Center Combines High, Low Tech to Save Energy
Low tech solutions yield about half of the energy savings in the first carbon-neutral LEED rated building in the US, the Aldo Leopold Foundation Center in Wisconsin. Built on PassiveHaus design principles, it uses 70% less energy than a typical 12,000 square foot building built simply to code. The center commemorates the life, beliefs and practices of Aldo Leopold, a forester, philosopher and poet.
A big part of the energy savings comes not so much from what is in the buildings, as in what is under them. Buried six feet underneath is a giant earth-tube cooling system comprising huge concrete pipes to cool the interiors above. As hot air rises out of the high roof vents, it draws the cooled air from the underground pipes up through the building. Not only is no air conditioning needed, but no pumps are needed to pump the cool air up, as with most ground heat exchange systems.
Variable speed pumps are used to provide the necessary flow of water to the radiant floors help meet heating and cooling needs. But as each zone in the building reaches the desired temperature, the pumps slow down, reducing energy consumption.
The buildings are separated by function. Seldom needed conference rooms or other occasional rooms are not heated or cooled when they are not in use. By separating the buildings into components and evaluating end purposes, an effort was made to break up programmed spaces based on use and thermal requirements. This approach allowed them to reduce mechanical equipment and energy consumption.
Source: Aldo Leopold Foundation