Dimitrios Kraniotis

OsloMet – Oslo Metropolitan University · Department of Civil Engineering and Energy Technology

Development of the method for automated and adaptive assessment of mould growth in the timber frame facade is presented. A heat, air, and moisture (HAM) transport simulation using the open-source Python library HAMOPY is validated against a well-established software (WUFI Pro 1D). Climate input of the reference year in Norway, Oslo is used in valid...

This paper describes a multistep approach that allows the design and assessment a hybrid, timber-based, facade system that can withstand current real conditions without being prone to mould. This approach is aligned with today’s drive for a more sustainable built environment. A typical office building with the hybrid system was simulated in a BES t...

In the world of cultural heritage, a wide range of artefacts and buildings are made of wood and, therefore, are subjected to moisture-induced stress and strain cycles, owing to environmental fluctuations. Simultaneous action of moisture and mechanical loads lead to a mechanosorptive effect on wood. Therefore, an increase in time-dependent creep, du...

This study introduces a Bayesian network model to evaluate the comfort levels of occupants of two non-residential Norwegian buildings based on data collected from satisfaction surveys and building performance parameters. A Digital Twin approach is proposed to integrate building information modeling (BIM) with real-time sensor data, occupant feedbac...

Optimizing building designs for energy efficiency and occupant comfort presents significant challenges due to the complex and often conflicting requirements of various stakeholders. Consequently, this study conducts a multifaceted sensitivity and economic impact analysis that aims to improve building performance in terms of energy efficiency and oc...

Life Cycle Assessment is necessary for evaluating the environmental impacts of buildings throughout their life cycle, considering factors such as energy consumption, emissions, and resource utilization. However, Dynamic Life Cycle Assessment introduces a temporal dimension, acknowledging that a building's environmental performance evolves due to te...

The objective of this study was to determine the minimum water vapor permeability of exterior wood coatings using hygrothermal and decay modeling. The approach is based on a worst-case scenario assumption, namely a moisture trap at a given wood moisture content underneath a coating. The minimum limit of vapor permeability of the coating was determi...

Due to today’s sustainability concerns, we must find ways to decrease, the CO 2 footprint of the products and systems that are used in buildings. The StaticusCare project, funded by EEA/Norway Grants, emerged from this need, since it aims to decrease the greenhouse gas emissions associated to the construction industry by developing a hybrid timber...

Materials production dominates the total Greenhouse gas (GHG) emissions in the construction industry. On the other hand, most existing building stocks are expected to last for the next 30 years, which can contribute to increasing resource efficiency, reducing environmental impact, and creating social, cultural, and economic values for society. Ther...

Historic masonry buildings are an integral part of human cultural heritage, and they need to be preserved for future generations. Brick is susceptible to frost damage which is common in regions with cold and humid climates. The frost damage on the masonry walls is accumulated over the years becoming more and more critical for the integrity of the h...

The objective of the study was to determine the influence of wood coatings for CLT on the moisture buffering capacity and the indoor environment regarding relative humidity and heating demand. Based on the results of a previous screening of a wide range of coatings, three commercial products were chosen: a flooring oil, an alkyd-based interior wall...

This poster intends to summarize the main conclusions of the seminar "A road for adaptation of bridge to climate change" held in Lisbon (September 27, 2022) under the ClimaBridge Project funded by EEA Grants. This seminar brought together experts from the bridge engineering field and academia, climatologists, bridge authorities, and decision makers...

Climate change is expected to significantly affect the interior climate of old, leaky buildings without HVAC systems. As a result, the items of cultural significance that are hosted indoors will experience new ambient conditions, which will affect their degradation. In the current research, the impact of climate change on the biological, mechanical...

Numerous buildings fall short of expectations regarding occupant satisfaction, sustainability, or energy efficiency. In this paper, the performance of buildings in terms of occupant comfort is evaluated using a probabilistic model based on Bayesian networks (BNs). The BN model is founded on an in-depth analysis of satisfaction survey responses and...

This contribution presents the work of research and technical development for designing a novel method for monitoring and predicting the weathering of cultural heritage, in particular of stones and timber used historically as building materials. An apparatus for long-term field tests was designed in its hardware and software components with a twofo...

The climate of the city of Tønsberg in Norway is cold and humid. As a result, the brick-made historic buildings in this city are threatened by frost damage. Climate change is expected to affect the action of this degradation mechanism. In the current research, climate data resulting from the REMO2015 driven by the global model MPI-ESM-LR were used...

The novel Pulse technique measures the building airtightness in a dynamic approach, involving a low-pressure pressurisation process, typically in 1–10Pa. It is known that the wind effect is one of the main sources of uncertainty for airtightness testing. The literature review revealed that the wind impact on measuring building airtightness has been...

Climate change is anticipated to affect the degradation of the building materials in cultural heritage sites and buildings. For the aim of taking the necessary preventive measures, studies need to be carried out with the utmost possible precision regarding the building materials of each monument and the microclimate to which they are exposed. Withi...

This paper presents a comprehensive approach to elucidate the mechanical and thermal aspects of coating layers integrated with organic-based PCMs. In that respect, three sets of cement mortars were studied experimentally to underline the significance of PCMs proportion. From a mechanical point of view, the strength of specimens cured at 20 °C resul...

Straw bale is a low embodied energy and technically acceptable thermal insulation material. As per today, there is a lack of standardized technical data on utilizing straw bale in building construction, while the existing research studies rather focus on limited specific experimental or computational scenarios without summarizing in an organized wa...

Straw bale constructions are considered as a promising solution towards the goal of decarbonisation of building sector. In particular, its use as an alternative thermal insulation and load-bearing material has been promoted. This study provide a thorough review of material properties of straw bale including mechanical, thermophysical and hygric. Fu...

Several studies underline the dramatic changes that are expected to take place in nature and environment due to climate change. The latter is also expected to affect the built environment. Particular emphasis is currently given to the impact of climate change on historical structures. Within this context, it is important to use simple methods and n...

Emphasis is currently given to the impact of climate change on cultural heritage sites and buildings. In this study the climate change impact on the hygrothermal performance and the biodeterioration risk of an historic timber building is examined. The investigated construction is a two-storey building located in southern Norway and dates back to 14...

Thermal energy storage with phase change materials (PCM) is a promising candidate to promote resource sustainability in buildings. The intelligent selection and usage of a PCM within the structure of a building poses a challenging engineering task due the highly dynamic nature of occurring heat transfers. This work features a step-by-step FEM model...

In recent years there has been a greater interest in developing new more sustainable solutions in the construction of buildings and in particular of large commercial and industrial buildings. This study analyses the feasibility and degree of sustainability of using cross laminated timber (CLT) as building material in industrial buildings in Nordic...

Requirements for measuring the building airtightness have been proposed and included by many countries for national regulations or energy-efficient programs to address the negative effect of poor airtightness on building energy performance, durability and indoor environment. The methods for measuring building airtightness have continuously improved...

Use of massive wood has increased during the last decade. The concept of massive wood, mainly as cross laminated timber elements (CLT), has become a popular building method for new constructions, both in public and private sector. Massive wood elements take advantage of wood as building material, also as an indoor climate buffer. Moholt 50|50 is a...

This work conceives a numerical modeling approach for the practical application of phase change materials (PCM). Momentum, energy and mass conservation are implemented in a coupled manner including auxiliary algebraic equations for phase change functionality. Key element of the modeling approach is the introduction of a so-called mushy zone at the...

Wood as hygroscopic material has the capacity to absorb moisture and thus to moderate the indoor relative humidity (RH) in a building, resulting in lower ventilation demand. In addition, when moisture migrates in hygroscopic structures energy is released through latent heat phenomena. The diurnal variation of moisture content in wood hold a potenti...

The hygrothermal surface conditions of a façade is important for the degradation of the façade material as well as for the energy budget of the building. The distribution of short term variations of the temperature and moisture in the façade is often neglected in degradation studies that will typically treat the whole façade equally. The moisture a...

The use of wood in built environments has been increasing during the last decades, and more focus has been set on the influence of wood surfaces on indoor environments on the objective and subjective measures of human well-being. In addition, the moisture buffer capacity of hygroscopic materials, such as wood, has been under investigation in order...

The production of industrially coated wooden claddings has been strongly increased in Scandinavia during the last years. In the beginning of this development, industrial coating processes included solely the application of pigmented primers; these however provide only a short protection of the wood surface and the application of a top coat is requi...

Hygroscopic materials exhibit moisture buffering capacity which can regulate the indoor relative humidity (RH) and may lead to potential energy savings. When RH increases indoors, hygroscopic materials absorb vapour from the surrounding air that consequently undergo a phase change-from vapour to water in the hygroscopic structure of the material. T...

The capacity of hygrothermal materials to buffer the maxima and minima of relative humidity indoors has been discussed and presented during the last years. In particular, the wooden surfaces have the potential to contribute to the reduction of the mechanical ventilation loads and consequently to the energy demand and consumption. In this paper, the...

Variations in micro climate induce shrinkage and swelling of wooden beams. The dimensional changes depend of the orientation of the annual growth rings and the moisture content of the beams. This causes laminated timber to experience different deformations than solid wood. A producer of element buildings with joists of laminated wood, have experien...

Hygroscopic materials hold the potential to reduce ventilation loads in a building by damping the peak fluctuations of the indoor relative humidity. Of particular interest is the moisture buffer capacity of wooden surfaces. This paper investigates, the response of Norwegian spruce (Picea abies) samples to changes of indoor relative humidity as well...

The weathering of wooden surfaces is caused by mould growth and lignin deterioration. For well insulated buildings, the effect of the interior climate is small and sometimes negligible. This paper describes two simple models for surface temperature and moisture on a wooden façade for use with mould growth models. The models are driven by exterior...

The interaction of the wood surface and indoor climate has been of increasing interest the last decade. The fluctuating air humidity reacts with the wood surface to seek equilibrium moisture content. This reaction is crucial when experiencing a sauna. The instant heat contribution of the latent heat from the released damp when pouring water on the...

Mold growth on the surface of wooden façades is usually dealt with by using surface treatment such as paint with fungicides. However, new developments in architecture are moving towards less use of coating, and more use of untreated wooden claddings. Mould growth is well understood and described, and several models for predicting mould growth on bu...

The recent project Wood-Energy, Emissions, Experience (WEEE) has investigated the influence of wood surfaces in indoor environments on objective and subjective measures of human well-being. Among the findings is a substantial effect on room temperature in a fluctuating relative humidity due to the heat of sorption of water vapours. The wood surface...

Interior wooden surfaces have the capacity to buffer the maxima and minima of relative humidity (RH) indoors. Especially in high performance buildings, where high airtightness levels as well as high indoor air quality (IAQ) are required, there is great potential for energy savings by reducing the mechanical ventilation demand. The last decade, the...

The moisture buffer capacity of hygroscopic materials and the potential to reduce heating, cooling and ventilation loads has been discussed the last decade. Hygroscopic materials can moderate the levels of indoor relative humidity reveals that the moisture produced in a space is not directly transferred to the ventilated air as assumed in current v...

High relative air humidity (RH ≥ 85%) during growth leads to stomata malfunctioning, resulting in water stress when plants are transferred to conditions of high evaporative demand. In this study, we hypothesized that an elevated air movement (MOV) 24 h per day, during the whole period of leaf development would increase abscisic acid concentration (...

Air infiltration holds a central role in building energy consumption. Towards the demand of achieving nearly-zero energy buildings, a better understanding of the phenomena should be provided. Temperature gradients (buoyancy forces) pressure differences (wind) are crucial parameters for the air infiltration through buildings envelope. In particular,...

Carbon dioxide has already been recognized as a potential tracer gas for estimating the mean air exchange rates of a room or building. The wind direction and mean wind velocity have also been identified as critical factors that affect the air infiltration. In this paper, the indoor CO2 concentration has been logged at three specific points in an of...

Wind-driven air infiltration has been recognized among the major reasons for energy loss in buildings, and the impact to energy efficiency under steady conditions has been reported and issued as part of many building codes. The nearly zero-energy building demand makes uncontrolled leakage paths even more undesired and creates the need for further i...

Uncontrolled leakage paths in a building have been very clearly stated as an important reason for energy loss. While steady state conditions have been studied in detail there are only few studies that discuss the influence of natural unsteady phenomena to the infiltration rates of a building. In the current numerical study, unsteady wind conditions...

The existence of air leakages in a building has been very clearly stated as an important reason for energy loss. The decrease in the efficiency of the mechanical ventilation has also been clarified. The global demand for achieving nearly zero-energy buildings makes the uncontrolled leakage paths even more undesired. Despite the fact that steady sta...