The Dubuque plant’s design may earn some of those “above and beyond” points in areas including recycling, water and heat efficiency. In the Materials & Resources category, Hormel use of recycled content in construction may earn it extra points if it exceeds 75 percent. The shell alone will top 58 percent recycled content through the use of recycled precast concrete, steel and other materials.
In addition to using recycled construction materials, the Dubuque plant will manage construction waste, using separate dumpsters and recycling scrap wood, steel, concrete and paper-based materials. Extra LEED credits may come in two more areas with particularly positive impact.
“The biggest thing Hormel is doing in this regard is a new heat recovery system, which may earn the project extra points,” says Rens. He credits Sayles as “the mastermind” behind the mechanical designs that will recover heat from ammonia and air compressors, boilers and other systems. This heat will be routed to a holding tank and used to heat the plant’s offices as well as preheating water for plant washdown uses.
Hormel also will score Water Efficiency points and perhaps extra credits for its use of a “gray water” system that will replace 100 percent of the water used to flush toilets, versus the typical 20-30 percent for which LEED awards credit in the typical commercial/office application.
“It all adds up,” Sayles says. “That water would normally go down the drain because it’s no longer potable. Now it can be used.”
Heat recovery: beyond geothermal
Booming year-over-year sales of Hormel’s shelf-stable Compleats led to plans for the new plant in Dubuque, Iowa.
Water recovery has found its engineering match in Hormel’s latest heat recovery designs, which will reclaim enough heat throughout the plant to heat 100 percent of the plant’s process sanitation water. So when the plant’s retort cookers enter the cooling cycle, Sayles explains, “rather than just reject that heat energy to the atmosphere with a cooling tower or down the drain, as has been done traditionally, we've engineered the process so we can actually save that energy.”
This amounts to the industrial equivalent of geothermal energy, which gets a lot of attention in the green home-building world for its use of ground-source heat pumps that extract heat from or return heat to the ground to regulate interior heating or cooling.
“But for our project, we believe we’ve one-upped that common type of geothermal usage,” says Sayles. Hormel’s system will work “very much like a conventional geo-thermal system, but instead of using the ground, we’re using energy that’s already available out in the plant, making it substantially more efficient.” In summer, heat shed from offices will feed the process, while in winter, process heat is fed to office heating.
It’s a more closed-loop system that bypasses the “geo” altogether. It might be... aero-thermal?
Additional energy conservation and savings will come from HVAC systems, which should gain credits in the LEED category of Energy & Atmosphere. “What you can measure and control, you can improve,” Pfeil explains. Toward this end, the new plant will track energy use with a new level of specificity. Instead of the traditional “main utility room” approach and total-plant utility measurement, the plant is broken into several zones, each with its own metering devices and controls.
“We won’t just know that we’ve used X-hundred pounds of steam today; we’ll know which processes used how much of what resource,” Sayles explains. Beyond conservation and savings, this system will play a vital role in the overall asset maintenance and management program by tracking performance and helping to track degrading performance of specific systems, such as air leaks in compressor banks.
Hormel also should earn Sustainable Sites credits by providing erosion and sedimentation management that exceed environmental regulations. The 39.5-acre campus will employ a low-maintenance, no-irrigation landscape. Also in this LEED category, innovations include reflective white membrane roofing and concrete paving for passive cooling and “heat island” effects. (Permeable concrete also reduces runoff.) Also, car/van-poolers will get preferred parking. The facility has locker rooms with showers available for bicycle commuters and all employees.
“You wouldn’t think that erosion control would be a big factor, but it is,” Rens says, citing LEED’s Environmental Quality criteria. Even during construction, he says “a clean job site is a safer job site,” which will be managed to minimize hazards. For example, as early phases come on-line, crews working with epoxy floors or adhesives will schedule work on the weekends.
Site design features such as erosion control can reduce dust in ductwork and keep moisture from degrading drywall at entrances. Additionally, the plant’s ductwork will be sealed and covered for cleanliness and thermal efficiency.
Build the best, the points will follow
While not all measures will make point thresholds, the company is pursuing them anyway. For example, Hormel is adding more than 200 skylights and light-dimming controls. They won’t reach a Daylight & Views credit-earning threshold, but are an example of Hormel’s belief that some practices are “the right thing to do,” Rens says.
Corporate sustainability goals from the top-down led Hormel engineers to partner with longtime design-build partners at Gleeson Constructors to put green goals on paper.
Likewise, “Thermal Comfort” points are likely outside consideration in a plant where significant process areas require a 40ºF temperature limit.