Thermal efficiency of a natural home

Imagine you’re cooped up in a hot room. The sun bearing down and the heat coming through the walls like they are non-existent. It is so hot and stuffy that you give in and blast the air conditioner.

When the room reaches arctic temperature you turn it off as you think back to the pain of your last electricity bill.

A couple of hours later, you start the loop again.

Frustrating…

As we look for alternative, higher-performance solutions, we stumble upon Hempcrete.

But does it really perform all that well? Let’s dive a bit deeper into it.

To fully understand the insulative abilities of Hempcrete, and to offer more than just pop-science that is often prevalent in the industry, I would like to present some actual research from the engineering department at Ben-Gurion University in Beersheba, Israel

The researchers aimed to test the thermal performance of four individual test dwellings, each spanning one hundred square meters with an interior ceiling height of 2.7m and three north-facing windows.

They found that the most widely used energy-efficient building material in Australia, Hebel board, still requires almost 500 kWh more energy per year than Hempcrete.

Furthermore, when testing the 'cheap' option over the course of a year, the hollow-core brick required an additional 6,128 kWh of energy.

Hempcrete required only 706 kWh per year, with only 13 kWh of that being in the summer when the air conditioning is briefly switched on during heatwaves. Researchers also found that in the winter, energy usage was almost half that of a Hebel-clad dwelling.
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The black line represents the simulated summer heatwave temperatures over a three day cycle. You can see the different materials Hempcrete (LHC), Autoclaved Aerated concrete or Hebel (AAC), Hollow Core Brick (HCB), Expanded Polystyrene Foam (EPS

The energy consumption of the Hempcrete structure was the absolute lowest. Using Hempcrete (LHC) instead of HCB (hollow core brick) can save almost 95% of the energy required for cooling and around 82% of the energy required for heating. Not only that, the Hempcrete building was the most comfortable during those unbearable heat waves.

The energy consumption of the Hempcrete structure was ∼7 kWh/m2/year, which fits the highest standards of what is called ‘nZEB’ or a Nearly-Zero Energy Building.

Let’s just think about that last sentence for a second…

A nearly zero energy building; pretty cool huh?

Thanks again for your time. We spend a great deal of time writing about Hempcrete. That’s because our purpose at RespiraBuilt is to help as many people as possible to insulate our homes with a naturally grown, carbon-sequestering carbon-based lifeform that not only provides the best thermal comfort but also has a genuine positive impact on the environment, and our bank accounts!

See you in in the next blog post for Pillar #2: Hempcrete's active moisture management!

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Reference:

Lime Hemp Concrete with Unfired Binders vs. ConventionalBuilding Materials: A Comparative Assessment of EnergyRequirements and CO2 EmissionsRotem Haik 1,* , Isaac A. Meir 2 and Alva Peled 21 Energy Engineering Unit, Ben-Gurion University of the Negev, Be’er-Sheva 84105, Israel2 Department of Civil and Environmental Engineering, Ben-Gurion University of the Negev,Be’er-Sheva 84105, Israel

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