The thermal conductivity and diffusivity of un-fired clay bricks, a straw-clay mixture and straw bales have been measured using a thermal probe technique, with an iterative method for data analysis. The steady-state air-to-air thermal transmittance, or U-value, and the time-dependent thermal properties of some proposed sustainable earth wall constructions are presented. Sustainable cavity walls of un-fired clay bricks with paper, straw or wool cavity insulation have thermal transmittances less than 0.35 W/m²K, and therefore meet the current United Kingdom Building Regulations.
A review of possible methods for thermally up-grading existing earth walls, by adding an internal insulated timber frame construction, again demonstrates possible compliance with the current UK thermal regulations.
Authors:
- D’Alessandro, Francesco
- Baldinelli, Giorgio
- Bianchi, Francesco
- Sambuco, Sara
- Rufini, Alessandra
Link: http://www.sciencedirect.com/science/article/pii/S0950061817320585