While the rest of the world is taking small steps to reduce energy consumption – changing to CFL light bulbs or Energy Star appliances, and installing a few solar panels – one Hong Kong-based architecture firm has taken it about 1,001 steps further. Arguing that zero-impact is just not enough, 10 Design created a concept for the Indigo Tower which actually interacts with its surrounding environment to purify urban air using passive solar and nanotechnology.
We’re not saying that all those little steps toward energy efficiency are not noble and very necessary, but why not aim beyond zero-impact to actually create positive impact? Buildings are huge energy and resource hogs – estimated by the Whole Building Design Guide to account for 39 percent of energy and 68 percent of electricity consumed in the United States. This also means they are responsible for a large amount of greenhouse gases and pollutants – 38 percent of the carbon dioxide, 49 percent of the sulfur dioxide and 25 percent of the nitrogen oxide found in our atmosphere. So if they’re making all this mess, why not find a way to design buildings that also clean up after themselves? Looking to nature for inspiration, architects are slowly implementing components like green roofs, passive solar techniques and graywater systems to help integrate buildings into their surroundings for a mutually beneficial result.
Inspired by nature’s cleansing processes, 10 Design gave their high-rise Indigo Tower the power to pull dirt, grease and bacteria out of the air using a nano coating of titanium dioxide (TiO2) on the outer skin. TiO2 is a strong oxidation agent, so as sunlight hits the building, the chemical reaction neutralizes the toxins with only water and oxygen as byproducts. During the day, the reaction would be powered by sunlight, and at night a series of ultraviolet lights powered by solar PV panels would continue the reaction and create the building’s signature indigo glow.
The building’s structural design is meant to optimize this cleansing process, with three separate bars to maximize the surface area for titanium dioxide and create more south-facing walls for maximum sun exposure. The structure also increases wind speed across the surface and creates cross ventilation to power vertical-axis wind turbines. The building texture mimics the titanium dioxide molecule and naturally collects water, the chemical reaction’s byproduct, and slowly releases it as rainwater. The design team also gave building inhabitants a nice place to relax with gardens at regular intervals down the tower, with plants that filter graywater from the tower and drain down into a large pool around the base which acts as a heat sink to reduce the building’s heat island effect.
According to Design 10, if all the buildings in a city’s central district utilized this Indigo Tower design, air pollution could be reduced by up to 80 percent. While we may be a long way off from building just one, let alone multiples of this type of building, we do applaud that more and more designers are beginning to think about buildings that function as more than just a simple interior. As Indigo Tower designers Ted Givens and Benny Chow argue, “We are developing a building that moves beyond itself, and through an act of supererogation, attacks the more global conditions. One building can only have so much of an impact but a collective, that leads by examples and inspires other progressive green thinking, can truly make a difference.”