Quasi steady state and dynamic hygrothermal performance of fibrous Hemp and Stone Wool insulations: Two innovative laboratory based investigations

Abstract

Moisture and heat management properties of Hemp and Stone Wool insulations were studied by mounting them between a hot and a cold climate chamber. Both insulations were exposed to identical hygrothermal boundary conditions. Quasi steady state and dynamic tests were carried out at a range of relative humidity exposures. The likelihood of interstitial condensation was assessed and equivalent thermal conductivity values of the insulations were determined. The adsorption-desorption isotherms of the insulations were also determined in a dynamic vapour sorption (DVS) instrument. It was observed that the likelihood of condensation was higher in Stone Wool insulation than in Hemp insulation. Hemp insulation performed better in managing moisture due to its high hygric inertia and water absorption capacity. It was observed that the equivalent thermal conductivity of Stone Wool insulation was dependent on enthalpy flow and phase change of moisture. The equivalent thermal conductivity of Hemp insulation was close to its declared thermal conductivity in dynamic conditions when high relative humidity exposures were transient. In quasi steady state boundary conditions, when the insulation was allowed to reach the equilibrium moisture content at ranges of relative humidity, there was a moisture dependent increase of thermal conductivity in Hemp insulation.

Dynamic behaviour of bio-based and recycled materials for indoor environmental comfort

“…Bio-fibre composites can be developed using agro-waste which is widely available. Internal wall bio-based panels optimisation has been studied by other researchers (Arnaud, 2009;Pavlik et al, 2011;Latif et al, 2016;Latif et al, 2018). However, the knowledge on the passive mechanisms and the hygroscopic characteristics associated to these materials is not fully mastered.…”

Dataset on the hygrothermal performance of a date palm concrete wall

“…and Ferroukhi et al. [[5], [6], [7], [8]]. The experimental device consists of a climatic chamber in order to simulate the outdoor climate conditions and another cell to simulate the indoor conditions, as shown in Fig.…”

“…Fig. 6 summarizes the two scenarios that were programmed to apply dynamic boundary conditions to the outer side of the wall, based on previous works [6,[9], [10], [11]]. Temperature and RH data collected at the different depths of the wall, as well as indoor and outdoor conditions are presented in Fig.…”

In situ assessment of the fabric and energy performance of five conventional and non-conventional wall systems using comparative coheating tests

“…Bio-based building materials, especially insulations and envelope-integrated insulation materials, are produced from renewable sourced and show excellent hygric and good to moderate thermal performance [20][21][22]. Takano et al [23], in their study on the energy performance of a hypothetical building model in Finland, observed that the life cycle energy balance of the cellulose fibre insulation was the lowest among all building materials including EPS (expanded polystyrene) and glass wool insulations.…”