Thermal Transport in Straw Insulation

Abstract

An evacuable guarded hot plate for thermal conductivity measurements between À200 and 800 C was used to investigate the heat transfer in barley straw. The different thermal transfer mechanisms (solid, gaseous conduction and infrared-radiative heat transfer) as well as coupling effects were separated. The measured thermal conductivities ( ¼ 0.041 W m À1 K À1 ) are similar to those of conventional insulation materials such as foams, glass or mineral fibres which are widely used as building insulation materials. Straw from barley or wheat, which is a low-cost, renewable material readily available world-wide, is therefore an interesting alternative to conventional insulation materials.

Processed Straw as Effective Thermal Insulation for Building Envelope Constructions

“…Moreover, a lack of information about strongly horizontally or vertically oriented straw can be noticed. The experimental results of other researches on straw bales show that the obtained results vary from 0.041 W/(m-K) to 0.140 W/(m-K) (Beck et al 2003). The difference between these results is related to several reasons.…”

“…For manufacturing thermal insulation materials from renewable resources, available thermal conductivity is approximately 0.041 W/(m-K) and even lower (Beck et al 2003). The thermal conductivity of materials under realistic conditions may increase.…”

Investigation of thermophysical properties of alates (swarmers) termite wing as potential raw material for insulation

“…Their assumption has origin from the work of [32], [33], [34], [35], and [36]. Beck et al [37] and [38] in their contribution assert that the total thermal conductivity in highly porous insulation is the sum of the gaseous conductivity, gas k , the solid conductivity, solid k , radiative conductivity rad k and a coupling term couple k , expressing mathematically thus…”

Studies on the Thermal Conductivity of Composite Materials Based on Local Renewable Resources / Kompozicinių Termoizoliacinių Medžiagų Iš Vietinių Atsinaujinančių Išteklių Šilumos Laidumo Tyrimai

“…Gaminant termoizoliacinę medžiagą iš vietinių atsinaujinančių išteklių -šiaudų, įvairių stiebinių augalų, sunaudojama daug mažiau energijos, pavyzdžiui, presuotiems šiaudams gaminti sunaudojama vos 14 MJ/m 3 energijos (Gurskis, Juodis 2008). Tokių medžiagų šilumos laidumo koeficientas gali siekti 0,040 W/(m·K) (Beck et al 2004). Gaminant termoizoliacines medžiagas iš ekologiškų vietinių išteklių -augalų reikia mažiau energijos, nes jau pati gamta sukūrė akytą augalo stiebo struktūrą.…”