Monika Woloszyn

• PhD
• Professor at Université Savoie Mont Blanc

Although hygrothermal properties of rammed earth represent great potential for improving thermal comfort during hot summers, still little knowledge is available about this topic. The literature lacks complete sets of hygrothermal characteristics of rammed earth, although they are fundamental for heat and moisture transfer modeling necessary to pred...

Présentation de l'activité scientifique du thème BASE pour l'exercice 2022 - 2023

In the coming years, heat waves will be more and more frequent and severe. New buildings must ensure thermal comfort to the occupants despite hot summer conditions, using passive elements, such as solar shadings, night ventilation, limitations of heat gains. The real performance of such systems is very sensitive to occupants’ actions in the case of...

Rammed Earth (RE) is a traditional technique based on the compaction of local soil, avoiding long-distance transportation and carbon emissions processes typical of concrete production. Nevertheless, RE presents limited mechanical performances and low resistance against water. Cement is usually added to improve RE properties to comply with the const...

Rammed earth construction is built by compacting humid soil into formworks layer by layer, using clay fraction as only binder between the grains, without firing procedure. At this stage, the material is unsaturated, and capillary forces thus act to add cohesion between particles. Indeed, a peculiarity of this material is its high hygroscopic capaci...

A Demand-controlled ventilation (DCV) has been recognized as a promising solution for decreasing energy consumption while ensuring good Indoor Air Quality (IAQ) in buildings. However, its application in the residential sector has increased first recently. Implementation of DCV systems brings the problem related to assessing their performance, not o...

This study aims to check the compatibility of a selection of waste and recycled biopolymers for rammed earth applications in order to replace the more common cement-based stabilization. Five formulations of stabilized rammed earth were prepared with different biopolymers: lignin sulfonate, tannin, sheep wool fibers, citrus pomace and grape-seed flo...

The determination of the moisture diffusivity in the capillary range is studied for rammed earth building materials, using the X-ray method. To prevent liquefaction and expansion of these materials during the capillary absorption test, a brick wick and paper are added as lower sample parts and a confining sealing is utilised. Since the wick and pap...

Traditional techniques of construction using natural and locally available materials are nowadays raising the interest of architects and engineers. Clayey soil is widely present in all continents and regions, and where available it is obtained directly from the excavation of foundations, avoiding transportation costs and emissions due to the produc...

Decision making for the energy retrofit of building stock is key to improve the energy efficency and comfort in buildings. This article present a methodology developped in order to help the building stock or real estate manager to imrpove the efficiency of his buildings. The methodology is based on the multi-objective optimization of the retrofit,...

The use of hygroscopic materials indoors has a significant impact on the hygrothermal balance of a room air. It affects both the temperature and the relative humidity. Numerical tools still lack of accuracy in predicting these parameters and some discrepancies are observed between their predictions and experimental measurements. It may be caused by...

Given that performance-based approaches secure maximum energy consumption for new buildings in more and more building codes and standards, such approaches could ensure that ventilation is designed to avoid risks for occupants’ health. We have developed a performance-based approach for assessing ventilation indoor air quality (IAQ) performance in lo...

The importance of earthen construction materials lies in their widespread availability combined with a low embodied energy. Chemical stabilizers are commonly used to improve their durability and mechanical performance. The main drawbacks are the high environmental impact of their production, the loss of recyclability, and the possible reduction of...

Ventilation of residential buildings is an important area of research, since it addresses crucial issues: providing healthy indoor air to occupants, avoiding condensation risk and damage of the building, as well as ensuring energy efficiency. With regard to regulatory or labeling requirements, performance-based approaches for ventilation should be...

In the field of building performance simulation, there is a growing interest for the use of sensitivity analysis (SA) and uncertainty analyses (UA), that enable to estimate the uncertainty in model prediction and to identify which model inputs are mainly responsible for this uncertainty. However, several methods exist, with different capabilities a...

The capillary absorption test is redeveloped for rammed earth building materials. Since these materials liquefy and expand upon contact with water, the standard method must be modified to tackle this material evolution during the test. Firstly, a thin permeable wick and paper are applied as lower sample parts, to counter the liquefaction. It is sho...

This paper describes the effect of inorganic adsorbents on the hygrothermal performance of insulating materials. The addition of the inorganic adsorbents leads to significant effect to the microstructure and mechanical properties of these materials. The thermal conductivity rang of the materials containing adsorbents from 0.095 to 0.116 (W/m−1 K−1)...

In an energy performance verification protocol, comparing predicted and measured data is a difficult task, especially due to uncertainties surrounding the building and its environment. This work presents the development of a global approach aiming to qualify "real" performance versus expected one, by exploiting measured data (including weather and...

The present paper gives an overview of a French national project on building performance. Named COMEPOS, started in 2013, it focuses on « Positive Energy » detached houses. It consists in the design, construction, operation and evaluation of 20 inhabited and innovative houses. This collaborative project includes constructors, industrial and academi...

The building materials used indoors constantly interact with the environment in which the occupants live. Recent studies have shown that natural materials, such as wood, can improve human well-being. In addition, the building materials facing the indoor air are able to adsorb and desorb water vapour from their surface and exchange it with the surro...

Due to the environmental impact of building materials, researches on sustainable materials, such as bio-based and earth materials, are now widespread. These materials offer numerous qualities such as their availability, recyclability and their ability to dampen the indoor relative humidity variations due to their hygroscopicity. As these materials...

The hygric characterisation of authentic rammed earth materials is presented. Since these materials expand and liquefy upon contact with moisture, currently available methods are adapted to deal with this material evolution during the tests. In particular a thin permeable wick is introduced in the capillary absorption test. Moreover, confined and u...

Moisture buffering can be defined as the effect on the atmosphere of the exchanges of water vapour between the surface layers of hygroscopic materials and the indoor environment. Since latent heat exchanges take place, the moisture buffering has a direct thermal effect on summer indoor temperatures. We propose here to investigate this thermal effec...

This study examined the impacts of detailed envelope airleakage distribution and internal partition walls airleakage on the ventilation performance of a detached low-energy house. We used a multizone modelling approach based on CO2, humidity and formaldehyde to calculate indoor air quality (IAQ) performance indicators. Impacts of uneven envelope ai...

Clay-based materials are the most traditional components of buildings. To improve their performance in a sustainable way, agents can be mixed to fired clay acting as a pore-forming factor. However, firing temperatures highly influence their microstructure which is closely linked to a material’s final performance as a ceramic block. To highlight the...

Prediction of moisture transfer within material using a classic diffusive model may lack accuracy, since numerical simulations underestimate the adsorption process when a sample is submitted to variations of moisture level. Model equations are always established with assumptions. Consequently, some phenomena are neglected. This paper therefore inve...

This paper tends to evaluate the robustness of the summer building behaviour under inhabitants’ actions. For that, two indicators are introduced: the resilience and the resistance of a building at the inhabitants’ action. They evaluate by means of time-dependent sensitivity analyses how in amplitude and duration an inhabitants’ action impacts the i...

Heat and mass transfers are becoming increasingly important in the field of building physics. They should be considered to predict building performance, especially for a wall containing highly hygroscopic materials. The moisture balance at the room scale is influenced by air leakage and moisture sources, by the vapour transfer within the material a...

Models for the prediction of heat and mass transfers in building porous materials have been developed since the 90’s with simulation programs such as MATCH, UMIDUS, DELPHIN and Wufi. These models are used to analyze the physical phenomena occurring and particularly the impact of moisture on buildings’ energy performance and durability. With this go...

Cet article présente un nouvel outil pour réaliser de l'optimisation multi-objectif sur les parcs de bâtiments gérés par le même le gestionnaire. Il détaille comment interfacer de l'optimisation multi-objectif avec de la simulation thermique de parcs de bâtiment sous le langage Modelica dans l'optique de trouver les stratégies optimales de réhabili...

Comparer données simulées et mesurées en vérification de performance énergétique est un exercice délicat, notamment de par la présence de différentes sources d'incertitudes liées au bâtiment et à son environnement. L'article présente le développement d'une démarche globale visant à qualifier, à partir des mesures disponibles, la performance réelle...

This article proposes to study the impact of envelope and internal partition walls airleakage distributions, on the indoor air quality (IAQ) performance. It is based on a preliminary performance-based approach using formaldehyde with three emission levels (low, medium, high). This multizone modelling (CONTAM) approach uses as performance indicators...

Dans un contexte de garantie de performance énergétique, l'évaluation de la performance réelle des logements est un nouvel enjeu. Dans les constructions récentes de type BEPOS (bâtiment à énergie positive) le comportement des occupants est connu pour avoir un impact fort sur la performance énergétique. De plus, dans ces nouvelles constructions, l'é...

The rehabilitation of ancient rammed earth houses, as well as the use of earthen materials in modern constructions, are a growing matter of concern, especially in area such as Rhône-Alpes, France, where 40% of old constructions are in rammed earth. A current pathology observed for this type of construction is related to the rising damps, for which...

In order to save energy used to heat or cool buildings and to improve the inhabitants comfort, control of humidity inside buildings must be improved. This can be done by using buffering materials able to absorb and release moisture when necessary. Natural fibers and mineral absorbent are good candidates to manufacture such materials. The aim of thi...

The standard methods to determine the vapour permeability and the moisture sorption curve may lack of accuracy since discrepancies are observed when comparing numerical predictions to experimental data. Moreover, these properties are determined in steady state conditions while the numerical predictions are carried in transient regime. Thus, this pa...

Reducing energy consumption for future buildings using bio-based insulation materials is currently one of the most attractive research pursuits. The specific purpose of this research was to optimize thermo-pressing conditions for new low-environmental-impact bio-insulation fiberboards from bamboo fibers and protein-based bone glues. The microstruct...

This study focuses on manufacturing bio-insulation fiberboards from bamboo fibers and bone glue, modified with sodium lignosulfonate. The microstructure of these boards is investigated by mercury intrusion porosimetry. The porosity and average pore size of boards are decreased; however, the specific pore surface is increased with the presence of bi...

This study focuses on manufacturing by thermo-pressing new low-environmental-impact bio-insulation fiberboards from bamboo fibers and bone glue, modified with sodium lignosulfonate. The aims are to measure moisture buffer value, water vapor permeability, bending properties, thermal conductivity and vapor sorption isotherms of these materials. The m...

The impact of air infiltration on the hygro-thermal performance of a wall is closely linked to the air dispersion inside it, but there is a lack of experimental studies and methods for the air path investigation within light-weight wall assemblies. A new technique has therefore been developed, consisting in an innovative use of fluorescein micro-pa...

In order to improve understanding of heat and mass transfer, two studies, at material and room scale are carried out. At the material scale, a dynamic experimental method has been developed and applied to a wood fiber previously characterized with classical steady-state methods. Several samples were subjected to successive steps of relative humidit...

Hygrothermal analysis of building envelopes requires high-quality input data and thoroughly tested models. To improve a model developed in Comsol Multiphysics for assessing the hygrothermal performance of rammed earth constructions, flexible dynamic small-scale experiments are presented. First, an experimental study shows the sample production, tes...

In order to improve understanding of heat and mass transfer, two studies, at material and room scale are carried out. At the material scale, a dynamic experimental method has been developed and applied to a wood fiber previously characterized with classical steady-state methods. Several samples were subjected to successive steps of relative humidit...

The present work is the hygric characterization of wood fibre insulation boards, using dynamic measurements of relative humidity and sample weight, analyzed in the frame of Bayesian inference for parameter identification under uncertainty. It is an attempt at identifying detailed profiles of moisture-dependent properties, and thus a relatively high...

Available throughout the world and used in construction for thousand years, earthen materials are known to improve indoor air quality while keeping the internal temperature relatively stable. In Rhône-Alpes, France, the rammed earth technic is the most spread and consists in compacting layers of earth, one by one, within a framework. Current therma...

Poor airtightness in buildings can lead to an over-consumption of energy and to many issues such as moisture damage and poor indoor climate. The timber frame constructions are particularly subject to air leakages, and further knowledge in this field is needed to meet the regulation requirements tightened by the development of low-energy and passive...

Heat and mass transfers are becoming increasingly important in the field of building physics. They should be taken into account to predict building performance, especially for a wall containing highly hygroscopic materials. They are usually characterized using steady-state measurements, while real hygrothermal loads in buildings are always dynamic....

This paper presents a review of the use of model reduction techniques for building physics applications. The use of separated representations, the so called Proper Generalised Decomposition (PGD), is particularly investigated. This technique can be applied for efficient building physics modelling at different levels: the wall and multizone models,...

Given that airtightness is recognized as an essential issue for low-energy dwellings, today it is often included in energy performance (EP) calculations, frequently through single-zone models with uniform air leakage. Because more consideration is often given to EP than to indoor air quality issues, air leakage through internal partitions is often...

Good building airtightness is of major importance to achieve energy efficient buildings. Poor workmanship may lead to unintended air transfer through the building envelope. The tradititional method to assess the impact of air leakage on the building heat loss is to add an infiltration heat loss to the existing conduction heat loss, without consider...

Available throughout the world and used in construction for thousand years, earthen materials are known to improve indoor air quality while keeping the internal temperature relatively stable. In Rhône-Alpes, France, the rammed earth technic is the most spread and consists in compacting layers of earth, one by one, within a framework. Current therma...

RESUME. La prise en compte des transferts couplés chaleur-masse devient nécessaire afin de prédire la performance d'un bâtiment, notamment lorsque la paroi contient des matériaux hygroscopiques. La caractérisation des matériaux se fait habituellement avec des mesures en régime permanent ce qui n'est pas en accord avec les charges hydriques d'un bât...

RESUME. Aujourd'hui il existe assez peu de retour d'expérience concernant les consommations réelles des bâtiments récents en lien avec les performances annoncées à la conception. 'Comment comparer la phase d'exploitation et la phase de conception de manière pertinente ?' est une des questions à laquelle il faut chercher des réponses. Dans cet artic...

Poor airtightness in buildings can lead to an over-consumption of energy and to many issues such as moisture damage and poor indoor climate. The wooden frame constructions are particularly subject to air leakages and further knowledge in this field is needed to meet the regulation requirements tightened by the development of low-energy and passive...

Detailed modelling of air leakage paths through complex building wall assemblies is a challenging task. It requires transient modelling of diffusion and advection phenomena through fluid and solid domains, including porous materials and air channels. In this article, the development of a numerical model coupling heat air and moisture transfers (co...

The goal of this paper is to identify the effects of liquid water and water vapor in-pore transports as well as phase changes on the hygrothermal behavior of earthen buildings. Indeed, one of the main assets used to promote these constructions is their role in moisture buffering hence temperature and relative humidity quality controlling. However,...

Moisture transfer has an impact on the energy performance and on the durability of the building walls. The objective of this study is to assess these impacts on a light wall mainly composed of wooden materials. To perform this study a coupled heat and moisture transfer model has been used and a simulation tool has been developed. Yearly simulations...

Innovative and efficient ways to carry out numerical simulations are worth of investigation to reduce the computational complexity of building models and make it possible to solve complex problems. This paper presents a reduced order model, based on Proper Generalised Decomposition (PGD), to assess 2-dimensional heat and moisture transfer in walls....

The energy consumption of a dwelling depends on energy performance of building envelope and of HVAC systems, as well as on the behaviour of occupants. This paper is interested in virtual tests of a 'positive energy' dwelling in a Mediterranean climate. It is based on a real house under construction. This article analyses the influence of the occupa...

Experimental measurements are often used to validate or calibrate numerical models. Many authors report good agreement between experimental measurements and numerical simulations of thermal behaviour of walls, and notice stronger discrepancy while assessing moisture transfers. One of the possible reasons for this discrepancy is the difficulty to me...

In France, the building sector is the main energy consumer. Moreover single-family houses represent about 60% of annual dwelling construction. Assessment of energy performance of occupied dwellings is therefore a very important task. The challenge is therefore to reduce the number of sensors, while keeping a sufficient robustness and precision of t...

The moisture balance at room scale is influenced by the air change rate, moisture production and vapour transfer with the envelope. However, results may differ strongly from one study to another depending on the sizing of the ventilation system, the boundary conditions and the modelling of vapour transfer in the walls. This paper aims to provide a...

Abstract Air leakage through the building envelope can lead to an increase in energy consumption and to potential moisture damages. This paper investigates the impact of air leakage on the hygrothermal field in a ceiling section insulated with blown-in cellulose, and separating an attic space from a heated indoor space. This ceiling section, part o...

Mastering building airtightness is essential to meet the requirements of current and future building codes, not only for saving energy but also for ensuring moisture safety. Perfect airtightness is difficult to achieve: failures are often observed, due to bad design or poor workmanship. Some published investigations proved that leaking air mostly f...

In Europe, low energy buildings become common for new constructions and life cycle assessment (LCA) is increasingly used to assess their environmental performance. The overall objective of this study is to investigate known challenges related to buildings LCA such as biogenic carbon accounting and dynamic and prospective aspects, and to discuss how...

The present paper investigates the performance of gradient-free inversion methods applied to the characterisation of hygrothermal properties of building materials. Two classes of techniques were implemented to solve the inverse problem of envelope parameter identification: the Covariance Matrix Adaptation evolution strategy, and Bayesian inference....

L’étude des transferts d’humidité et de chaleur dans les parois des bâtiments fait l’objet d’un intérêt croissant de la part de la communauté scientifique. En effet, avec le développement de bâtiments à faible consommation énergétique, mettant pour certains en œuvre des matériaux fortement hygroscopiques dans leur enveloppe, se pose la question de...

Excessive levels of moisture in buildings lead to building pathologies. Moisture also has an impact on the indoor air quality and the hygrothermal comfort of the building's occupants. A comprehensive list of the possible types of damage caused by moisture in buildings is discussed in the present paper. Damage is classified into four types: damage d...