Just as farm operations have become more sophisticated through the years, so too have the shop buildings that keep expensive machinery and equipment in tip-top condition. A prime example can be found in rural St. James, Minnesota where the new shop of LeRoy and Dave Leinenweber is a model of efficiency, both operationally and in terms of energy consumption.
The metal-skinned shop is large—80’ wide x 120’ long x 38’ at the peak—and features hydraulic doors from Schweiss Doors of Fairfax, MN. One of the three is a 20’ x 50’ unit. Located at the east end of the shop, it has a smaller 14’ x 16’ door built right into it. At the west end is another hydraulic door, this one measuring 20’ x 32’, which makes it possible to drive equipment in one end of the building and out the other. The building also utilizes a geothermal heat system, has hot and cold running water, fluorescent lighting equivalent to a basketball arena, and thermo-pane windows.
The building provides ‘shirt sleeve’ comfort regardless of outdoor conditions, thanks to the use of solid-core structural insulated panels from Energy Panel Structures Inc. of Graettinger, Iowa, for the shop’s R-44 roof and R-33 wall construction.
The energy-saving features are not only environmentally friendly, they are owner-friendly as well. It is estimated the shop will cost the Leinenwebers about $800 annually to heat and cool versus $4,000 if Lp gas was used, and $5,000 if electricity (at 5 cents/kw) was the energy source. But there were additional up-front costs that more conventional approaches wouldn’t have incurred. The investment for the geothermal system—including some 9,600 sq. ft. of polyethylene lines buried 7’ to 8’ deep in the earth, plus 7,000’ line feet of 5/8” oxygen-bearing pex tubing stapled to the board insulation beneath the seven-inch-thick concrete floor—was about $35,000.
So with the added upfront cost, why go with geothermal? Dave Leinenweber responded, “It was a difficult choice because of the additional initial investment. But the pencil pushing shows a payback in 5 to 7 years.”
It was to make the geothermal system even more cost efficient that the solid-core structural insulated panels were chosen for the building’s roof and walls. The panels are made by sandwiching a core of rigid foam insulation between two skins of wood. “This system is 15 times more air-tight and two times more energy efficient than stick buildings, plus it’s much quicker construction,” Leinenweber indicated.
The roof panels are 44’ long x 3’ wide panels x 10” thick. The wall panels are 18’-tall x 3’ wide and 7 ½” thick. The wall panels sit on a 3’ concrete sill. The concrete foundation, dug 48” into the earth, is faced with Dow Styrofoam-brand insulation on both sides.
The geothermal system has three separate distribution points to more efficiently provide three zones for the heating/cooling system. Also two air-handler systems mounted 18’ high on the south wall use the chilled water from the geothermal unit to air condition the building during the summer.
The concrete floor got ‘surfaced’ with a ‘hardener/densifier’ product that causes a chemical reaction ostensibly to provide longer life. “It interacts with limestone in the concrete and hardens the top surface immensely,” explained Leinenweber. Also two Nussbaum jumbo-lift scissor hoists will be positioned into the floor.
Why hydraulic doors? “I’ve seen hydraulic doors in other shops and farm buildings. I like the ‘awning affect’. You open up this 20’ door and you have a 20’ awning over the concrete approach ramp.” And why the smaller door within the bigger door? “That’s a matter of ‘energy savings’. We just need the big door for combine and bigger equipment. The smaller door opens quicker and will save heat in colder winter conditions,” explained Leinenweber.
A 5-hp electric motor powers the big hydraulic door with 2-hp motors handling the other two doors. Additional bracing was welded into the frame of the bigger door to support the extra weight of the 2nd door built within the framework of the 20’ x 50’ unit. Also special latch pins provide stability to both doors when closed. Foam insulation provides R-20 values for all three doors.
Going with Schweiss hydraulic doors was basically because this Minnesota manufacturer could deliver exactly what the builder needed to meet the engineering safety specs of this door-within-a-door configuration. “They’ve got a proven reputation. Any questions were quickly answered either by phone or direct visits to our farm,” related Leinenweber.
The contractor for the geothermal system was St. James Electric. The general contractor for the building was Tedd Grunzke, Shed and Shinola, LLC, Cleveland, MN.
For more information about products from Energy Panel Structures, visit www.epsbuildings.com.