The building sector is on the front lines of the sustainability movement – meaning that innovations within the industry stand to make a substantial impact on climate change and the environment. This month, we’re taking a look at developments in building materials that promise to make green building a smarter, more efficient and effective vehicle for a shift in the global paradigm of sustainability.
Phase Change Materials
Phase change materials (or PCMs) are set to radically cut heating and energy bills with their revolutionary properties that enable them to become liquid in warm temperatures, and then solidify as temperatures begin to drop – absorbing and releasing heat respectively to keep indoor environments comfortable, all for a fraction of the energy costs of current systems.
Because the energy required to change states in materials is relatively high, PCMs are an ideal candidate for thermal insulation, keeping rooms cool on hot days by storing the sun’s energy in molecular bonds as the material ‘melts,’ and then releasing this energy to keep rooms warm after sunset when the PCM reverts to solid form. Ice, a primitive but widely used PCM, operates under the same principles, but scientists have been developing materials which change phases at more useful temperatures than water.
A brand new building at the University of Washington, for example, incorporates ‘bioPCM’ gel into the facility’s walls. Derived from vegetable oils, the gel is a mere 1.25 centimeters thick, but has the same insulating properties as more than 25 centimeters of concrete. Experts say the industry, which currently hovers near zero, could be worth $130 million in just a few years.
Building with Trash
Refuse is becoming a growing problem in many parts of the world, and the silver bullet of construction materials would be a low-cost, environment-helping method of transforming discarded plastics and other waste into durable building products.
Solidia Technologies, a New Jersey based company, uses a process called low-temperature solidification to combine minerals, carbon dioxide and waste materials to form building materials that are more durable than concrete.
These manufactured stones and plastics are some of the greenest building options around – while most materials release green-house emissions in the production process, Solidia’s materials actually remove carbon in two ways – one, by sequestering carbon dioxide used in the manufacturing process, and two by removing waste material from landfills that would otherwise return carbon and other compounds to the atmosphere.
So far, materials for floors, walls, countertops, and facades can be created in just a few hours, and customized for particular projects – making Solidia material a strong candidate for replacing concrete altogether. Its low temperature manufacturing also allows other interesting possibilities, such as incorporating sensors or photo-voltaic elements into material for roads, infrastructure, and buildings.
Architect Rick Crook, who designed New York’s first LEED Platinum building, recently told Wall Street Daily, “As architects designing for a sustainable future, we are seeking new products that are not just qualitatively better, but radically address our carbon footprint. I believe Solidia Technologies has developed such a material.”
Concrete is the most widely-used construction material in the world, but the cheap production costs mask a heavy environmental toll – cement manufacturing accounts for nearly five percent of all manmade carbon dioxide emissions, with one ton of Portland cement releasing nearly 800 kilograms of carbon dioxide into the atmosphere because of the heavy carbon pockets in limestone and the high heating temperatures needed to drive the chemical reactions in the manufacturing process.
Novacem, a London-based startup, is pushing an innovative magnesium oxide-based cement alternative that is actually carbon-negative, pulling more carbon out of the air in its production process than it releases. With a lower reaction temperature and carbon dioxide recycling processes, one ton of Novacem cement absorbs a net total of 100 kilograms of carbon dioxide from the air.
With comparable performance and falling manufacturing costs, Novacem hopes to transform one of the most polluting aspects of the building sector into a carbon sequestering industry over the next few decades to help combat rising climate change.