Natural Materials for Thermal Insulation: Mulch and Lava-Rock Characterizations

Aurélien Jean (1) , Craig Adams (2) , Mario Medina (2) , Frédéric Miranville (1)

1 PIMENT - Physique et Ingénierie Mathématique pour l'Énergie, l'environnemeNt et le bâtimenT
2 University of Kansas [Kansas City]

This paper reports on the thermal characterization, via the thermal conductivity, of natural materials, such as mulch and lava rock and their usefulness as building insulation. Experiments were carried out using a scale one monitored wall (i.e. heat flux and temperature sensors) exposed to a heating source on one side and to an air conditioned space on the other. The wall system was composed of an 8.85 cm thick cavity, where the mulch and lava rock were placed. The cavity was enclosed between two layers of pine wood (40 mm thick each). After the experiments and statistical data manipulation, the estimated thermal conductivity of the materials were 0.48 ± 0.001 W.m -1 .K -1 and 0.129 ± 0.003 W.m -1 .K -1 for mulch and lava-rock, respectively. That is, mulch has a thermal conductivity comparable to that of bulk hemp while lava rock has a thermal conductivity comparable to that of hemp brick. These values indicate the usefulness of mulch, compared to the impracticality of using lava-rocks materials for building insulation.

Mots clés: Natural materials; Thermal conductivity; Thermal characterization; Construction; Mulch; Lava-Rock

Domaines: Thermique [physics.class-ph]; Eco-conception; Construction durable

Aurélien Jean, Craig Adams, Mario Medina, Frédéric Miranville. Natural Materials for Thermal Insulation: Mulch and Lava-Rock Characterizations. Applied Mechanics and Materials, 2014, Machinery Electronics and Control Engineering IV, 705, pp.8 - 13. ⟨10.4028/www.scientific.net/AMM.705.8⟩. ⟨hal-01110505⟩