Cement modeled after elephant ears could aid in energy conservation by reducing building temperature
In a groundbreaking development, researchers at Drexel University have unveiled a novel building material that could significantly reduce energy consumption for heating and cooling. The material, inspired by the heat-regulating ears of jackrabbits and elephants, is designed to passively heat or cool surfaces such as walls, floors, and ceilings.
The key component of this innovative material is paraffin, a phase-change material (PCM) that absorbs and releases thermal energy when it transitions between solid and liquid states. This property allows the material to regulate building temperatures and reduce the demands on heating, ventilation, and air conditioning (HVAC) systems.
During periods of increasing temperature, the paraffin melts, absorbing a significant amount of heat energy from the surroundings. This process stores heat, preventing the indoor temperature from rising quickly. Conversely, when the temperature drops, the paraffin solidifies, releasing the stored heat back into the environment, helping to maintain a more stable indoor temperature.
This thermal energy storage and release create a buffering effect that reduces temperature fluctuations inside buildings, leading to lower demand for HVAC systems. The material also benefits from a higher heat storage capacity, with testing scenarios showing it can reduce the indoor air temperature by around 5.75°C when walls and ceilings contain 75% paraffin wax content.
The design integrates bio-inspired channels, reminiscent of elephant ears, to optimise heat exchange and distribution within the cement, enhancing its effectiveness in moderating building temperature. The diamond-shaped channel grid design was found to deliver the best combination of strength and thermal performance.
The study, published in the Journal of Building Engineering, aims to address the massive energy demands of buildings, which account for nearly 40% of total energy use. The team plans to experiment with different kinds of phase-change materials, alternate channel designs, and larger building material samples. These trials will take place over longer periods and in more varied environmental conditions to assess long-term performance.
Adding fine aggregates improved the material's durability without affecting its vascular system. The material stayed strong for practical use despite the hollow channels. Paraffin, with a melting temperature around 18 degrees Celsius, makes the material effective in cold climates.
Rhythm Osan, an undergraduate student in Drexel's College of Engineering, is a co-author of the study. The innovation uses a combination of a specially printed polymer matrix and concrete to form a vascular system within the surface. This unique design allows the material to absorb excess heat during hot periods and release it during cooler times, thereby smoothing temperature swings inside buildings and reducing reliance on HVAC energy.
- The innovation in building materials, inspired by nature and primarily comprising paraffin as a phase-change material, promotes the integration of robotics and science in the industry, aiming to minimize energy consumption and optimize temperature regulation.
- The study's findings suggest that the financial sector could greatly benefit from this energy-saving material, as it promises to significantly reduce the energy demands of buildings, contributing to a greener and more sustainable future.
- As the research progresses, exploring various types of phase-change materials, alternative channel designs, and larger building material samples, the scope of science and robotics in the industry expands, potentially revolutionizing the way we construct and power our buildings.
