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Quirky but efficient, Taiwan's first carbon neutral building opens

2011/01/13 14:56:54

Ask security guards at the main gate of National Cheng KungUniversity's campus in downtown Tainan just behind the main trainstation how to get to the“Magic School of Green Technology”or thenew“green building”on campus, and all you will get is a blankstare.

But ask one of them where the“building with the funny lookingroof”is, and the reaction is immediate: “Oh yeah. The Noah's Ark.Walk straight ahead, take one left and then a quick right and headstraight again and it will be right there.”

That building, officially opened Jan. 12 to great fanfare as theY.S. Sun Green Building Research Center, has a roof that is anythingbut conventional, with two solar chimneys, a natural roof garden,sun-shielding awnings, a wind turbine tower and a leaf-shaped solarpanel.

While some architects might feel less than flattered that theirdesign is best known for its“funny looking roof, ”the driving forcebehind Taiwan's first carbon-neutral building, National Cheng KungUniversity (NCKU) architecture professor Lin Hsien-te, takes it as asource of pride, because his vision of Taiwan's green building futurehas finally become a reality.

Lin, one of Taiwan's foremost green building experts, drewinspiration for the building from Noah's Ark, seeing it as a greenrefuge that could contribute to saving the planet and protectingbiodiversity.

At the building's ribbon-cutting ceremony on Jan. 12, VicePresident Vincent Siew called it“a milestone in Taiwan's greenrevolution.”

But the revolution Lin and NCKU have in mind for the building,which will serve as southern Taiwan university's internationalconference center and exhibit green building technologies, is tochange people's attitudes about what green building really involves,especially in Taiwan's tropical and sub-tropical climate.

“One of the biggest misconceptions about green building on themarket is that green building is high-tech. The solar power and greenbuilding our research team is promoting relies on ordinary andinexpensive technologies and locally sourced materials to achievehigh efficiency,”Lin told the Central News Agency.

The result is that this 4,800 square-meter“Magic School of GreenTechnology, ”the building's name before it was recently given a moreformal name by its main corporate sponsors, cost roughly NT$130million (US$4.41 million), or NT$27,000 per square meter, to build,no more expensive than a typical low-rise office building.

The project's overall budget was NT$180 million, and while Linsaid that some of that still remains, it also covered costs thatwould not normally be part of any office building project, such asexpenses for non-essential landscaping and road improvements madearound the building, or the building's energy management systeminstalled to test how much power it really saves over the next year.

So how efficient will this Noah's Ark be? Power efficiency isoften measured by EUI (energy use intensity), which divides the totalenergy consumed by the building in one year by the total floor space.Low-rise office buildings in Taiwan have an average EUI of 125kwh/square meter, but simulations done by Lin and his team suggestthat this office building will have an EUI of 43 kwh/square meter,saving roughly 65 percent in power.

To make the building carbon neutral, NCKU agreed to plant treeson a 4.7 hectare piece of land on one of its campuses along Taiwan'scoast to absorb and offset the carbon emissions produced by thebuilding's energy consumption.

The key to the building's efficiency lies more in its design thanactual high-tech gadgets. Lin's main weapons in the project werenatural ventilation with the help of a solar chimney, a technologythat has been around since at least the days of the Roman Empire, andceiling fans.

“We designed a natural ventilation system so that the building's300-seat auditorium does not have to be air-conditioned at least fourmonths of the year. From what I've seen so far, the results have beenreally good, and we might be able to do even better than that, ”Linsaid.

Taiwan's muggy, humid climate almost dictates that packedauditoriums have to be climatized for comfort year round, but theNCKU green building avoids that when outdoor temperatures fall below29 degrees Celsius by drawing cooler outdoor air into the auditoriumthrough outside vents.

It then flows from below the stage up through the sloping seatsto the back of the room, where it is then sucked out by the solarchimney located behind the solar panel on the roof.

The pull is created by the sun-heated chimney, with heatconcentrated in a black aluminum panel inside the chimney that helpsdraw out the conference hall's hotter air.

Lin's simulations show that the draft of just below 0.5meters/second will be able to turn over the air inside the auditoriumfive to eight times each hour, keeping it comfortable enough to avoidthe use of air conditioning even during muggy spring and fall months.

Ventilation in the building's offices operates on the sameprinciple. Each office has windows facing both outside and toward theinner atrium. That generates a cross-flow helped by slow-movingceiling fans. Hotter air that flows into the atrium is then drawnthrough the chimney seen in the roof garden.

Other design features that limit power usage include limiting thesize of windows to around 25 percent of the building's wall surface,using awnings that keep the hot summer sun out but the light from thelower-angled winter sun in, and using energy efficient lighting,without high-tech controls.

“We've been testing a light control system that saves 30-40percent of the power used by lighting, but it has an 11-year paybackso we may not stick with it,”Lin said.

On Wednesday, Lin seemed more relieved than excited that theproject, financed in large part by Delta Electronics Inc. founderBruce Cheng, along with 34 other corporate sponsors, was finallydone.

Originally scheduled to be completed by March 2010, it was heldback by interior design, landscaping, and bureaucratic delays.

“I'm just very happy that the building could meet theexpectations of the people who contributed to it. But the one thingI'm excited about is that it will continue to spawn green education.We have 12 Ph.D and master's students who are doing theirdissertations and theses about features of the building,”Lin said.By Luke Sabatier, CNA Staff Writer