Temperature dependence of sorption isotherm of hygroscopic building materials. Part 2: Influence on hygrothermal behavior of hemp concrete

Colinart, Thibaut; Glouannec, Patrick; Bendouma, M.; Chauvelon, Philippe

doi:10.1016/j.enbuild.2017.07.016

Cited by 37 publications

(15 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results are relevant with the temperature effect on sorption process highlighted in [21,45]. Moreover, the simulation with hysteresis gives better results than the simulation without.…”

Section: Accepted Manuscriptmentioning

confidence: 58%

“…Starting from the effective initial relative humidity and temperature determined in the previous paragraph with the hygric history consideration, two simulation runs are performed considering the temperature effect on sorption process, with and without hysteresis. The results are compared with the experimental data and the standard simulation results obtained when hysteresis and temperature effect on sorption are not considered.Temperature evolutions are not represented but, as observed in[45], few differences occur in the evolution of the temperature with or without consideration of the temperature effect on sorption process.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Experimental and numerical evaluation of the hygrothermal performance of a hemp lime concrete building: A long term case study

Moujalled¹,

Ouméziane

Moissette

et al. 2018

Building and Environment

View full text Add to dashboard Cite

Hemp-lime concrete (HLC) is a bio-based material which is currently undergoing a growing development. HLC is a low embodied energy material and an excellent hygrothermal regulator. Its thermal, hygric and mechanical properties are well known, and its capacity to reduce energy needs and to improve hygrothermal comfort is demonstrated across many laboratory and numerical studies. However, there are few works about its hygrothermal performance in real climatic conditions on the scale of a building. In order to address this issue, a long term in-situ measurement is carried out to analyze the hygrothermal performance of a HLC individual dwelling-house during 4 years. The analysis of the hygrothermal behavior of a wall is achieved by comparing measurements and numerical simulations results. In this study, two simulation tools are used and compared. The first tool

show abstract

Section: Accepted Manuscriptmentioning

confidence: 58%

mentioning

confidence: 99%

Experimental and numerical evaluation of the hygrothermal performance of a hemp lime concrete building: A long term case study

Moujalled¹,

Ouméziane

Moissette

et al. 2018

Building and Environment

View full text Add to dashboard Cite

show abstract

“…Again, the calculated small time scale RH dynamics was very notably underestimated compared to the measurements. In [21,22,23,24,25,26], the authors have studied the response of hemp concrete panels to controlled indoor and outdoor conditions. Even in these controlled operating conditions without solar radiation, most of these studies [21,22,26] lead to simulation results that underestimate clearly the small time scale RH dynamics.…”

Section: Simulations Of the Hive Demonstratormentioning

confidence: 99%

“…Even in these controlled operating conditions without solar radiation, most of these studies [21,22,26] lead to simulation results that underestimate clearly the small time scale RH dynamics. From that point of view, [23,24,25] seem to obtain better results playing on some parameters which have an effect on the hysteretic behavior of the sorption phenomena such as the initial water content (which is usually unknown) or the considered hysteretic model.…”

Section: Simulations Of the Hive Demonstratormentioning

confidence: 99%

Hygrothermal effects and moisture kinetics in a bio-based multi-layered wall: Experimental and numerical studies

Reuge

Collet

Prétot

et al. 2020

Construction and Building Materials

View full text Add to dashboard Cite

A bio-based multi-layered reference wall has been developed within the framework of the European ISOBIO project. One of the key points of this project was to be able to perform proper simulations of the hygrothermal transfers occurring inside such walls. Previous published investigations, also performed in the framework of this project, have demonstrated that the classic assumption of instantaneous equilibrium between local relative humidity and water content according to the sorption isotherm is not relevant for bio-based porous materials, where, in practice, a rather slow kinetics of sorption occurs. The theoretical background developed in this previous study is used here to determine the kinetic constants of the bio-based construction materials and to perform 1D hygrothermal simulations. The kinetics constants are determined thanks to a 1D cylindrical tool based on the local kinetics approach, validated against several experiments of sorption. Then, heat and hygric transfers recorded on a demonstrator building (The HIVE, Wroughton, UK) are analyzed and are simulated using two modeling tools: TMC based on the Künzel approach and TMCKIN based on the local kinetic approach. From the simulations, the local kinetics improves the small timescale RH dynamics. The comparison with measurements performed in the demonstrator confirms the relevance of the local kinetics approach.

show abstract

“…Again, the calculated small time scale RH dynamics was very notably underestimated compared to the measurements. In the studies of Lelievre et al [21], Colinart et al [22,23], Rahim et al [24], Fabbri and McGregor [25] and Seng and al. [26], the authors have studied the response of hemp concrete panels to controlled indoor and outdoor conditions.…”

Section: Introductionmentioning

confidence: 98%

Modeling of hygrothermal transfers through a bio-based multilayered wall tested in a bi-climatic room

Reuge

Collet

Prétot

et al. 2020

Journal of Building Engineering

View full text Add to dashboard Cite

A bio-based multilayered wall has been developed in the framework of the European ISOBIO project.A key point was to be able to perform proper simulations of the hygrothermal transfers occurring through the wall: local predictions are of first importance to characterize the behavior of the wall and thereafter its ability to ensure comfortable hygrothermal conditions inside buildings. A previous study proved that the conventional assumption of an instantaneous equilibrium between local relative humidity and water content according to the sorption isotherm is not relevant for bio-based porous materials, where in practice slow sorption kinetics occur. In the present study, an improved expression of the local kinetics is proposed and validated by sorption experiments. Then, Moisture Buffer Value tests are performed (Nordtest project's protocol). The simulations are adjusted to these measurements by using the inverse method in order to refine the knowledge of some critical parameters. Depending on the studied materials, the local kinetics constants are between 0.15 and 14 day -1 /(kg.m -3 ). Finally, the ISOBIO wall is studied in a bi-climate room under a wide range of operating conditions. Simulations carried out with the conventional approach (TMC) and the local kinetics approach (TMCKIN) are compared to measurements: this clearly shows that the latter is able to predict well the relative humidity dynamics while the former underestimates it by a factor up to 66%. These results highlight the relevance of the new expression of the local kinetics and its ability to describe well the local hygric dynamics is certainly an achievement.

show abstract

Temperature dependence of sorption isotherm of hygroscopic building materials. Part 2: Influence on hygrothermal behavior of hemp concrete

Cited by 37 publications

References 44 publications

Experimental and numerical evaluation of the hygrothermal performance of a hemp lime concrete building: A long term case study

Experimental and numerical evaluation of the hygrothermal performance of a hemp lime concrete building: A long term case study

Hygrothermal effects and moisture kinetics in a bio-based multi-layered wall: Experimental and numerical studies

Modeling of hygrothermal transfers through a bio-based multilayered wall tested in a bi-climatic room

Contact Info

Product

Resources

About