image from Legacy Center Web site - click for larger viewFresh air for the main building is drawn in through a network of concrete pipes buried several feet deep to take advantage of ground temperatures that are consistently near 52 degrees Fahrenheit.
The interior of the main building is heated and cooled using both passive and active systems. Active systems require the use of technology and energy to heat and cool. The passive system is part of the building's siting, orientation and design. Extensive use of windows on the south side of the building, with proper overhang to reduce overheating during the summer, combine with the thermal mass of the concrete floors and other building materials to provide heat from fall through spring. At the Center, a hallway on the south side of the building serves as a thermal flux zone to buffer the passive system from the rest of the building.
A ground-source heat pump system takes advantage of relatively constant ground temperatures to provide additional heat and cooling for the building. Fluid is circulated through a 200 foot loop of pipe that is buried vertically near the building. The fluid is then heated or cooled as necessary by a heat pump before being circulated through a radiant floor system in most of the building, and through radiators in the meeting room. Wood stoves and a Rumford fireplace burn locally harvested wood to provide additional heat when and where required. The Rumford fireplace, tall and shallow, is designed to reflect more heat into the space. I had previously seen Rumford fireplaces at the LEED Gold-rated Schlitz Audubon Nature Center in Milwaukee.
The Legacy Center is a net-zero energy consumer, thanks in part to reduced energy demand resulting from the energy efficient building design, use of day lighting and low energy lighting, and energy-efficient heating, ventilating and air conditioning. The Center captures renewable energy on site through a solar water heating system and one of the largest photovoltaic systems (solar electric) in the state of Wisconsin.
The solar water heating system at the Legacy Center utilizes an evacuated tube solar collector on the roof of the main building. The collector is quite unlike the flat-plate hardware that I was accustomed to seeing during my 10 years in the solar energy industry in Southern California during the ‘70s and ‘80s. Copper pipe encased in glass tubes carries a glycol solution to collect available energy; the fluid is circulated using a fractional horsepower pump. The collector was partially covered by snow on the day of the tour; when fully operational, the heat transfer fluid circulates through a heat exchanger in a storage tank to preheat the water going into the electric water heater. The system should provide most of the hot water required by the Center from spring through fall.
A much larger array of 198 photovoltaic (PV) panels fills the south-facing roof of the main building. These panels convert solar energy to direct electrical current. Inverters – streamlined boxes mounted on the wall of the mechanical room - convert the current to AC before it is fed into the utility grid. Graphic displays on the inverters documented the production of electrical energy, even on the overcast day of the tour. This type of system does not require on-site storage batteries which are expensive, have a limited life, utilize space, and create disposal challenges. Instead, net metering is used to account for the energy delivered by the system to the utility. The Legacy Center’s 39,6 KW PV system is designed to deliver 110% of the annual electrical energy required for operation of the Center. Thus far, actual performance of the system has matched design performance.
While the spirit, the words and the example of Aldo Leopold are timeless, I can’t help but wonder what he might think about all this new technology pressed into service in the name of efficiency and sustainability. After all, a cleaned-out chicken coop seemed to suit his purposes quite nicely. Thanks to Jennifer Kobylecky, the very knowledgeable and well-spoken Education Coordinator at the Legacy Center, for a great tour of this significant project and her follow-up help. For more information on the Center's carbon neutral design and water-conserving features visit the online tour of the center, or better yet, make the trip to Baraboo.
The Legacy Center is a net-zero energy consumer, thanks in part to reduced energy demand resulting from the energy efficient building design, use of day lighting and low energy lighting, and energy-efficient heating, ventilating and air conditioning. The Center captures renewable energy on site through a solar water heating system and one of the largest photovoltaic systems (solar electric) in the state of Wisconsin.
The solar water heating system at the Legacy Center utilizes an evacuated tube solar collector on the roof of the main building. The collector is quite unlike the flat-plate hardware that I was accustomed to seeing during my 10 years in the solar energy industry in Southern California during the ‘70s and ‘80s. Copper pipe encased in glass tubes carries a glycol solution to collect available energy; the fluid is circulated using a fractional horsepower pump. The collector was partially covered by snow on the day of the tour; when fully operational, the heat transfer fluid circulates through a heat exchanger in a storage tank to preheat the water going into the electric water heater. The system should provide most of the hot water required by the Center from spring through fall.
A much larger array of 198 photovoltaic (PV) panels fills the south-facing roof of the main building. These panels convert solar energy to direct electrical current. Inverters – streamlined boxes mounted on the wall of the mechanical room - convert the current to AC before it is fed into the utility grid. Graphic displays on the inverters documented the production of electrical energy, even on the overcast day of the tour. This type of system does not require on-site storage batteries which are expensive, have a limited life, utilize space, and create disposal challenges. Instead, net metering is used to account for the energy delivered by the system to the utility. The Legacy Center’s 39,6 KW PV system is designed to deliver 110% of the annual electrical energy required for operation of the Center. Thus far, actual performance of the system has matched design performance.
While the spirit, the words and the example of Aldo Leopold are timeless, I can’t help but wonder what he might think about all this new technology pressed into service in the name of efficiency and sustainability. After all, a cleaned-out chicken coop seemed to suit his purposes quite nicely. Thanks to Jennifer Kobylecky, the very knowledgeable and well-spoken Education Coordinator at the Legacy Center, for a great tour of this significant project and her follow-up help. For more information on the Center's carbon neutral design and water-conserving features visit the online tour of the center, or better yet, make the trip to Baraboo.
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