24 June 2014 — Around the world, there is an enormous level of innovation around sustainability products for the buildings sector. With buildings accounting for 19 per cent of greenhouse gas emissions in 2010, and the use of energy in buildings expected to double or even triple by 2050, innovations in the sector are going to become increasingly important in tackling climate change.
A German company, Xella, has developed low energy building blocks from sustainable materials. The block is made of sand, lime and cement – abundantly available raw materials – and the production process creates next to no CO2 emissions. Most of energy making it comes from curing the product with steam. Once manufactured, the lightweight blocks can be transported and used efficiently. The blocks retain their properties during the entire lifespan of a building: they never lose their energy efficiency or structural values. When the building is demolished the blocks can be used again for the manufacture of new aerated concrete.
The Haileybury Youth Trust has developed alternative soil blocks, created by mixing soil and cement, compressed into a mould. This produces an interlocking block (twice the size of a normal brick) that is stronger and more uniformly shaped than a conventional brick. And unlike other bricks, you don’t make it by firing it in the oven to produce greenhouse gas emissions. Also, the production is many times more cost-effective and efficient than traditional bricks. Two trained men can produce 500 blocks a day, on site.
Viewglass has created the intelligent window. These windows work like transition sunglasses for buildings. It transitions between four variable tint states, allowing visible light to shine in, and rejecting unwanted heat and glare – any time of the day or year. The glass can be programmed to adjust different facades of the building at different times of the day. The built-in algorithms predict when the sun moves or weather changes. As a result, the window tint changes automatically.
From the National Asphalt Pavement Association in the US, we have porous asphalt for storm water management. These pavements, used mostly for parking lots, allow water to drain through the pavement surface into a stone recharge bed and infiltrate into the soils below the pavement. The technology is really quite simple. The secret to success is to provide the water with a place to go, usually in the form of an underlying, open-graded stone bed. As the water drains through the porous asphalt and into the stone bed, it slowly infiltrates into the soil. The stone bed size and depth must be designed so that the water level never rises into the asphalt. This stone bed, often about 90 centimetres in depth, provides a tremendous sub-base for the asphalt paving.
Berlin based company X-runner venture has developed a waterless toilet. Its portable dry toilet separates liquids from solid waste, collecting the latter in a bin lined with a compostable bag. The system includes a weekly pick-up service. Bags of waste are collected from homes and treated in a hub facility through a composting service. Sounds like the old night carts? Maybe, but it’s perfect for addressing sanitation and sewage needs in cities, particularly slums. These are big ticket items.
Urban Engines uses algorithms to help cities work out key congestion choke points and times. The system is based on commuters using smart commuter cards already found in many major cities. The company tracks journeys made with those commuter cards, and uses that data to identify main areas of congestion, and at what times the congestion occurs. The system has already been employed in Washington DC, Sao Paulo and Brazil, helping provide valuable data for work with city planners.
In Singapore, commuters who have signed up and registered their commuter cards can earn rewards when they travel. They will earn one point for every kilometre travelled during peak hours, or triple that when travelling off-peak. The points earned can then be converted into discounts on future journeys, or put towards an in-app raffle game, where they have the opportunity to win sums of money. Urban Engines claim there’s been a 7-13 per cent reduction in journeys made during peak hours, with 200,000 commuters taking part.
Another innovation is Hempcrete, an alternative building material that uses the hurds, or inner woody core of the hemp stalk, in a mineral matrix to form a non-toxic, carbon-negative and energy-efficient material. When used for exterior walls, it lets water in without rotting or damaging the material. In a practical sense, instead of needing to build homes with space between exterior walls, which are then filled with insulation, you can simply use a Hempcrete wall. As humidity is taken in from the external environment, the Hempcrete holds that humidity until it is ready to be released again when the climate is less humid. And if too much of it is mixed during building, you can return it to the soil as a great fertiliser. Since hemp grows to maturity in just 14 weeks, it is a very powerful, versatile, cheap and sustainable solution.
Rotterdam tech firm The Archimedes has created a household wind turbine. The turbine combines the form of the nautilus shell, and the screw pump invented by ancient Greek mathematician Archimedes of Syracuse. The result: minimal mechanical resistance, allowing it to spin very freely and to operate quietly, eliminating any potential complaints from neighbours about blade noise. Additionally, the design is claimed to keep it always pointing into the wind for maximum yield. Used in combination with solar panels, a household could potentially run off the grid.
Architects and engineers are now working on new green tall buildings. Tapered forms and vents are reducing the wind loads that often drive requirements for structural mass. Water-recovery systems are capturing and reusing wastewater. And novel adaptations are expanding radiant heating and cooling.
GE has introduced technology to cool a fridge using a water-based fluid and magnets. GE believes the system could be as much as 20 per cent more energy-efficient than the appliance that’s currently keeping your milk from spoiling while reducing your monthly power bill. Instead of using a chemical refrigerant to draw heat away from the inside of the fridge, GE is using a magnetic field that agitates particles in a water-based fluid – presumably made of some highly patented mixture – that causes it to drop in temperature and in turn cool a refrigerator.
And still on the subject of fridges, a Danish firm has developed eCool, a new underground fridge, designed in Denmark, that keeps drink cans cool while requiring no electricity.The entire system has to be sunk underground to work and can stay installed in the soil for a year.
Brazilian firm Rivesti has developed tiles made from discarded plastic drink bottles. The company first purchases a PET resin — broken down from old plastic bottles — from recycling firms, before further purifying and treating the resin in-house with other recycled polymeric materials. From this, it creates a high strength tile with a unique aesthetic finish, available in 33 colours. According to Rivesti, one ton of recycled PET saves 7.4 cubic metres of landfill space, and saves the emission of 1241 kg of CO2. The company claims, therefore, that for every 40 square metres of Rivesti tiles installed, they avoid one cubic metre of the earth being used as a landfill, and save 166kg of CO2 being released into the atmosphere.