Investigating New Thermal Insulators Based on Cheap Natural Organic and Waste Materials: Part 1

Thermal insulation is a very important way to save energy in buildings or any other thermal application. For buildings, thermal insulation minimizes the heat transfer rate between a conditioning zone and its surroundings. For thermal applications, such as thermal storage tanks, it keeps heat or cold stored for later use. The current study is part of a project investigating thermal insulators made from cheap natural, organic and waste materials. The thermal conductivity of six different specimens of thermal insulator, made from used water cotton filter, chicken feather, walnut shell, sunflower seed husk, sawdust and ash, was measured experimentally. Industrial white glue was used as a binder to prepare the specimens. The sawdust and ash, of which the thermal conductivities are known, were chosen to validate the geometry of the specimens as well as the measurements of the testing device. The results showed that all types provide good thermal resistance performance. In particular, the insulator made from used water cotton filter was the best. It provided 0.0277 W/m k, which is a very practical value of the thermal conductivity in thermal insulation applications. This study will contribute significantly to sustainability by recycling wastes or using abundant natural and cheap materials in thermal insulators.