September 2011 Issue of Wines & Vines

Lean, Green Design

British Columbia's Tantalus Winery leverages efficient design in preparation for growth

by Peter Mitham
Perched on a gentle hillside above Kelowna, British Columbia, in the city’s historic Mission District, Tantalus Winery strives to honor its location while adopting winemaking practices that reflect long-standing commitments to environmental stewardship as well as sound business practices. Its vineyards, planted near where Rev. Charles Pandosy cultivated the province’s first winegrapes in 1859, trace their origins back to 1927 and the start of British Columbia’s commercial wine industry.

But with aims to boost production from just 4,500 cases to more than 10,000 cases in the coming years, Tantalus—pronounced like “tantalize” but ending with “us”—has developed a new winery that will make it possible to work efficiently and effectively with grapes from its 58 acres of estate vineyards. Winemaking in the new facility began with the 2009 harvest, and the premises opened to visitors in May 2010. The winery is awaiting certification under the LEED (Leadership in Energy and Environmental Design) program administered by the Canada Green Building Council. Tantalus expects to be the province’s first LEED-certified winery and one of just three in Canada (the other two are Stratus Winery and Southbrook Winery, both in Ontario.)

The 13,000-square-foot winery overlooks a planting of young Riesling vines on a west-facing slope above Okanagan Lake. The soils are primarily fine silt deposited by retreating glaciers. Current owner Eric Savics bought the property in 2004 from Den Dulik, who had been growing on the site for close to 60 years and whose father Martin was one of the valley’s first commercial winegrape growers.

“When he bought the property there was the classic Okanagan fruit salad of grape varieties, and so we decided to pull out some vines that we felt didn’t really work or make sense on the site,” says current winemaker David Paterson, who joined the winery from New Zealand in 2009.

Savics removed Cabernet Sauvignon, Merlot and Bacchus vines and replanted with Riesling, which now accounts for 70% of the winery’s production. Pinot Noir accounts for most of the rest, though the winery also produces a few hundred cases of Chardonnay and some Pinot Meunier for rosé. The grapes are entirely estate-grown in 36 bearing acres spread across two parcels. While not certified organic, the grapes are grown with as few chemical inputs as possible with substances approved for organic production used whenever possible. Many tasks such as weeding are done by hand with the help of two guest workers from Mexico.
Drawing in guests

Masks by Tahltan-Tlingit carver Dempsey Bob and paintings by Takao Tanabe ornament the tasting room at Tantalus Vineyards, where a panel of windows (actually discreet folding doors) open to showcase Riesling vines above Okanagan Lake. Another window offers a glimpse into the barrel cellar and production area below. A fireplace in the corner (more for aesthetics than comfort) and commercial kitchen just behind the tasting bar create the tasteful, modern environment for hosting guests. There’s even a small bedroom downstairs for guests and outlets for charging electric vehicles.

Yet even more than a year after the winery opened in May 2010, LEED certification still wasn’t available, a fact that is disappointing to general manager Jane Hatch, who remarks that it prevents Tantalus from fully touting its sustainable credentials.

“There are substantial additional costs involved in doing something like this,” she says, estimating the additional costs at no more than 10% while saying that facilities such as the winery’s water treatment plant were significant for a small business like Tantalus.

“Here we are with a building that’s been built to LEED standards, and we can’t use it in any of our marketing,” she says. “I have to say LEED, but uncertified. We would really like (certification).”

Hatch says the delay was attributed to a backlog at the Canada Green Building Council, which is responsible for certifying LEED-registered projects in Canada.
Geological limitations
The new winery incorporates a wall of the previous structure as part of its warehouse and backs into the hillside. The alluvial soils—primarily fine silts with some gravels and clays—made excavation for barrel cellars impossible, however. While the building’s design respected site topography, geological conditions limited what the topography allowed.

“We looked at digging barrel caves and things like that for temperature control and for humidity control, but the soils here just don’t support that,” Paterson explains. “We don’t really have any solid rock or anything we can blast into.”

A variety of native species including wild roses, wild strawberries and a selection of conifers and grasses were employed in landscaping to hold moisture in the soils without boosting irrigation requirements.

The winery itself is a sleek, two-story structure. Savics originally approached respected Vancouver architect Bing Thom to design a landmark building for Tantalus, but the job ultimately fell to another Vancouver firm, MQN Architects. The design specified a simple set of materials: The major elements were cement, steel and Kingspan panels, which were chosen for their insulative properties. Wall paneling is rated R-30 (a higher R-value indicates greater thermal resistance), while roof panels are R-45; fiberglass insulation is typically rated R-5. The orientation of the building keeps it largely hidden from the road above while maximizing the amount of natural light entering the building’s double-height production and warehouse spaces through clerestory windows.

It’s “just a small bank of windows, but the way that they’re placed in the architecture gives us enough natural light to work all day without having to turn on the big banks of lights, which obviously take a lot of electricity,” Paterson says. “The only times I really turn on lights is on bottling days, or if I really need a lot of light to rack barrels. But most of our operations are done under natural light.”

The use of natural light is one of the most obvious ways to increase energy efficiency, but Paterson says the design of the entire building has reduced energy consumption in mind. The key factor, especially in the Okanagan’s arid climate, where temperatures can range from -4°F to 104°F during the course of the year, is managing interior temperatures.

Energy efficiency
“We’re trying to keep a very regular temperature in the building so we can make very good wine,” Paterson says, “but doing that as energy-efficiently as possible.

“If it’s not well insulated, you’re going to be losing or gaining a lot of energy, depending whether it’s hot or cold outside, and then you’re going to be fighting that energy exchange the whole time.”

Kingspan paneling on the outside is a first line of defense. A heat-exchange system on the inside further reduces energy requirements for heating and cooling, while seamless Fusiotherm piping runs glycol throughout the winery for heating and cooling purposes. A natural gas-powered blast furnace is available for extreme winter weather.

Geothermal heating systems were investigated, but a backup system would have been needed to address the significant change in temperatures throughout the year—something that wasn’t cost-effective. Earth tubes, such as those in place at the new winery at the University of California, Davis, were too new at the time Tantalus’ reconstruction was first discussed, though Paterson feels they are superior to geothermal.

“It’s actually simpler than geothermal, it’s cheaper than geothermal,” Paterson says of the technology. “If they had been readily available when we built the building, that’s something we would definitely have considered.”

A sheltered crush pad just outside the main production area is large enough for basic processing, but Paterson clearly favors the interior space where a sleek drain system procured by Apollo Projects Ltd. of New Zealand immediately catches the eye.

“The drainage that we’ve put in, it’s just so much easier and nicer to process inside,” he says. It’s easy to see why: A single inch-wide crevice runs almost the length of the production area’s floor, which angles on an imperceptible 2º slope towards the opening.

The in-floor channel can be pressure-washed with debris channeled into a single basket that’s removed and dumped. It takes all of about 15 minutes—reducing time, labor and resource use.

“We use a lot less water to wash everything down, because we’re not having to use water to push things. Gravity’s doing most of that, and it’s just water giving it a little helping hand to the drain,” Paterson says.

Visitors often remark on the system, which doesn’t have removable drain covers and is narrow enough that tripping hazards are reduced. This complements the Dur-a-flex Inc. Poly-Crete urethane floor coating (installed by Marvelous Ideas Contracting Ltd. of Kelowna), which is soft enough to grip the soles of footwear and provide traction. The one drawback, Paterson notes, is that the floor coating scratches easily.

Tanks from Canada and New Zealand
A mix of older tanks from Ripley Stainless Ltd. in Summerland, B.C., and newer additions from New Zealand’s Crown Wine Tanks (chosen, like many other components for the winery, because exchange rates at the time garnered Tantalus a 10% savings over domestic suppliers) line the perimeter of the production room, with elevated walkways allowing cap management during fermentation and tank maintenance at other times. Wiring, glycol pipes and other systems nestle within the walls.

The winery’s effective control center is at the northwest corner of the room. A small lab area with a vineyard view offers the standard assortment of office and analytical equipment—a computer, beakers and the like—but Paterson is keen on the sophisticated VinWizard control panel.

VinWizard tracks temperatures throughout the winery as well as in the tanks during fermentation. When a change in glycol is required, compressed air opens or closes solenoid valves that regulate glycol flow.

“Very efficiently, I can have this at 16°F, which it is now; I can have the barrel hole at 19°F for malo and then drop it to 12°F once malo is finished. And I can keep the warehouse at a constant 12°-13°F all through VinWizard and all through just a little bit of compressed air and running two pumps that are pumping glycol around the building constantly,” he says, in a single breath that reflects the breadth of control VinWizard offers.

Better yet, if anything goes wrong Paterson can lift a handset on the control panel and get technical support from VinWizard headquarters in New Zealand.

“The fact that they give us such good technical support is fantastic,” he says. “I’m a winemaker, not an IT guy.”

One of the bugbears of the Okanagan that Tantalus’ new facility addresses is water quality. The region’s development has boosted demands on the region’s water table with residential uses prioritized over agriculture. Moreover, water sources are not the glacier-fed pools one might associate with Canada. Rather, water is loaded with pine tannins, a fact that prompted Paterson to specify a bank of carbon filters, cartridges and UV-purification processes to ensure that incoming water is as tannin-free as possible.

UV purification is also part of an on-site water treatment plant (see “BC Winery Ferments Water”) that provides Tantalus with water for irrigation or, at the very least, allows it to return clean water into the environment. The plant features a compact sequencing batch reactor (SBR) system that fit neatly into a 900-square-foot hut next door to the winery. The architecture is similar, with Kingspan panels that stabilize the interior temperature so treatment occurs continuously throughout the year.

The process is fairly straightforward: Wastewater—including process water from the winery, grape waste and sewage—enters a 12,000-liter anaerobic fermentation tank. The bacteria tackle it, and then 6,000 liters at a time are pumped through a single-batch reactor where the oxygen content of the mixture is raised to 6 milligrams per liter.

The aerated mixture then enters a final 12,000-liter tank where solids drop to the bottom, and the top 6,000 liters is decanted into a third part of the system where bag filters and UV filtration kill any remaining bacteria.

The system allows for a constant flow of water into the initial tank, allowing for a more compact system than many conventional systems. The whole process takes between eight and 12 hours at peak capacity, but at off-peak times the purification process is more leisurely and yields cleaner water.

Misting for humidity
Another water-related issue is directly connected with the local climate: The humidity in the barrel room, at the south end of the production area, has been difficult to manage because it should be about 75%, but the arid climate conspires to keep it at 71.5% in the 53.5°F environment—even with misting.

“To spray enough water to keep that humidity, the droplet size just seems to be slightly too large, and then if I take the droplet size down it doesn’t give me enough water to keep the humidity,” Paterson explains. The good news is that the building as a whole is efficient enough to give Paterson time to consider such conundrums.

“Basically, the building has enabled me to cut out a staff member,” he says. “It’s just myself and one other guy that run it over crush, and myself for the rest of the year.…(It) would usually be two people full time during the year. But because everything’s so nicely laid out and very efficient, I can run the whole thing.”

Paterson says he foresees adding a second person by the time the winery reaches its goal of producing 10,000 cases, but keeping the business as sleek as the building’s design will still be the priority.

“We’ll still try to keep it as efficient as possible,” Paterson says. “We’ve spent the money on the technology, so we shouldn’t put a whole lot in labor as well.”

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