In the construction industry, everything is starting to look a little greener – the windows, the lights, the plumbing, and the heating and cooling systems. So it should come as no surprise that engineers have been dabbling in a more eco-friendly version of insulation too. It’s commonly known as hempcrete, and it’s changing the way our buildings retain temperature and conserve energy.

What is Hempcrete?

Hempcrete is an insulation alternative that mixes industrial hemp fibers and binders that resemble concrete to serve as the protective envelope inside a building. It is a mix of hemp hurds and lime, but possibly also contains natural sand, pozzolans, and cement. Hemp is a key crop in Manitoba, and it is most commonly used there to produce oil and seed. Hemp is also commonly used to make fabric and paper.

Building experts have developed a method for mixing the leftover wood core with water and binders to form hempcrete. In recent years, hempcrete has been catching on as a building material in Europe, where hempcrete buildings stand ten stories tall. Today, it is also marketed under the names Canobiote, Isochanvre, and Canosmose.

How Hempcrete Works

The industrial hemp core has a high silica content, allowing it to bind well with lime. This material is lightweight – about a seventh of the weight of actual concrete. Not only can hempcrete be used in the structure of buildings, but it also acts as insulating infill between frames. Loads are carried by internal wood stud framing, making it a popular option for low-rise construction.

Environmental Benefits of Hempcrete

Many eco-friendly builders praise hemp as a material because it’s a fast-growing crop and it can grow well in both tropical and temperate climates. It’s also considered to be an eco-friendly crop because it absorbs carbon dioxide as it grows. Hempcrete is considered to be a more eco-friendly material than traditional insulation, which is made of hydrofluorocarbons and can actually produce potent greenhouse gases.

Construction Benefits of Hempcrete

Based on research findings, hempcrete has the ability to manage moisture inside walls and store heat energy.

“Hempcrete is used as an environmental barrier for providing resistance to heat transfer and managing moisture of the building envelope,” said Kris J. Dick, an associate professor in the Department of Biosystems Engineering at the University of Manitoba in Winnipeg and director of Alternative Village, its construction research facility. “Engineers and architectural designers practicing in the field of nonconventional material applications have clearly indicated a need for more design data regarding hempcrete.”

Hempcrete Testing

To test the durability and longevity of hempcrete in modern buildings, engineers have developed testing methods to evaluate its safety and efficiency. Alternative Village’s Kris J. Dick conducted research within a 23.8-square meter to compare hempcrete to traditional insulation in terms of energy, thermal and moisture performance. The results of his study indicated that the hempcrete provided a stable temperature inside the wall and that temperatures were consistent throughout the wall.

To broaden its mass appeal in the industry, however, more development and testing are needed to improve hempcrete’s structural strength. Experts are also beginning to consider other hemp-like natural materials that could be utilized for alternative insulation purposes as well.

Source: VIATechnik, LLC (via Linkedin)

More on biobased materials

The European Parliament’s environment committee on Tuesday 24 February 2015 backed a new limit on traditional biofuels made from food crops that critics say stoke inflation and do more harm than good to the environment.

Those seeking to promote a new generation of advanced biofuels made from seaweed and waste welcomed Tuesday’s vote.

But those who have invested in biofuels made from crops such as maize or rapeseed say it puts jobs at risk.

Current legislation requires EU member states to ensure that renewable sources account for at least 10% of energy in transport by 2020.

The European Parliament’s environment committee on Tuesday agreed that biofuel from food crops should not exceed 6% of final energy use in transport – a tougher limit than the 7% backed by member states last year.

It also agreed that negotiations between member states, the European Commission and the Parliament should start now on a legislative text, rather than waiting for a plenary parliamentary vote.

Thomas Nagy, executive vice-president at Novozymes , the world’s leading supplier of enzymes for the production of conventional and advanced ethanol, said Tuesday’s decision was long overdue and should help to spur necessary investment in the right kind of biofuels.

“A stable and effective framework is the only way forward to secure commercial deployment,” he said.

But ePURE, the European Renewable Ethanol Association, called on member states “to remain firm on a minimum 7% cap for conventional biofuels”.

Apart from the impact on food prices, using farmland to produce biofuels adds to pressure to free up land through deforestation, which can result in increased greenhouse gas emissions.

Green members of the European Parliament said Tuesday’s compromise deal meant changes in land use and the resulting emissions would be accounted for, although it said the proposals did not go far enough.

British liberal lawmaker Catherine Bearder also said the deal fell short, but would help to “combat deforestation, hunger and climate change”.

The European People’s Party, the main centre-right grouping in the European Parliament, regretted the outcome.

It said it could mean the failure of negotiations that still have to take place on a final legal text, protracting regulatory uncertainty that has already dragged on for years.

Source: euractiv.com