Endive cold-storage building features energy savings
RIO VISTA, Calif. — Richard Collins, president of California Vegetable Specialties, likes to threaten to perform a not-ready-for-primetime stand-up comedy routine.
RIO VISTA, Calif. — Richard Collins, president of California Vegetable Specialties, likes to threaten to perform a not-ready-for-primetime stand-up comedy routine. But he and his partners, S.C. Darbonne, Milly-la-Foret, France, don’t joke when it comes to the long-term viability and expansion of their Belgian endive production and marketing business. On May 18, the companies dedicated a 20,000-square-foot cold-storage facility expected to save up to 75% on electricity costs while providing a more stable environment for storing chicory roots used to produce endive. “French endive growers have a saying — the cold room is not a hospital,” Collins said. “The root goes into storage for up to 10 months and won’t come out any better. At best, it will come out in the same condition.” Collins was referring to the two-step process used to produce Belgian endive. Chicory seeds are planted in the spring in fields and the roots — harvested in the fall — are put in 29-degree cold storage from 30 days up to 10 months. As orders come in, workers pull the roots from storage, place them upright in trays and put them in temperature-controlled dark rooms to force leaf production. After about 30 days, workers harvest the tops, which are packed and sold as Belgian endive. This year, Collins said his company expects to produce a total of about 5 million pounds of white California Pearl and red Belles Rouges endive. Before the cold storage was built adjacent to the Rio Vista production facility, California Vegetable Specialties relied on Lomo Cold Storage, Live Oak, about 97 miles to the north, Collins said. ‘Off-the-chart’ insulation The building’s concept is the brainchild of Gary Block, a University of California-Berkeley associate architect professor who’s been experimenting with energy-saving construction techniques for nearly 40 years. The building’s frame is recycled steel trusses, said Cullen Burda, vice president of Integrated Structures Inc., project architect and engineer. What’s unique is the cement envelope design that provides an R-100 insulation factor and requires a smaller refrigeration unit to maintain cold temperatures, Burda said. California building codes only require R-28 insulation for similar buildings. “The insulation is pretty much off the charts,” he said. “They’re actually shutting down refrigeration between noon and 6.” By doing so, California Vegetable Specialties can avoid the higher-priced Pacific Gas & Electric peak electricity rates. The walls are composed of two layers of foam panels, between which expanding polyurethane foam is injected. Then about 3 inches of concrete is applied to both sides of the wall. Not only does this help maintain more stable humidity and temperature inside, but it also has a lifespan of at least 200 years and an earthquake seismic rating similar to those of police departments and hospitals, Burda said. Concrete envelope design isn’t new and has been used since 1994 on a handful of wineries, Burda said. In those structures, straw bales provided about R-87 insulation. This is the first time foam has been used, “and it worked like a charm,” he said. The energy savings will pay off the building in about 15 years, Burda said.