Table of contents

PREFACE

The 13-th International Research-Technical Conference on the Problems of Designing, Construction and Use of Low Energy Housing took place on September 11-13-th, 2018, in Kraków, Poland. The conference was organized by the Division of Building and Building Physics of Cracow University of Technology.

ENERGODOM 2018 was intended as an important event to bring together energy conscious scientist and practitioners. Participants from EU Member States and other countries were expected to define the present state of the art that exists in this field, to show not only advantages but also shades of contemporary standards and trends, pointing out the technical feasibility, social acceptance, and economic efficiency of low energy housing.

In 2018, we reemphasized, as we did in 2014, the necessity of extensive retrofitting of existing building stock to the low energy standard. Especially in Central Europe, poorly-insulated, large concrete slab buildings are densely populated, and for the next decades, these buildings will remain an important part of the total building stock. Another important aspect of thermal refurbishment of existing buildings is the improvement of indoor environment quality, including heating conditions as well as protection against overheating.

Prospective implementation of the EU Directive and the urgent necessity to rapidly increase the number of existing (not only newly built) nearly zero-energy buildings demands comprehensive actions and a new awareness of the investors, designers, contractors, and workers. Energodom 2018 conference was intended as a tool helping to create this awareness.

Since the very beginning, this conference stood as a forum for those interested in low energy housing, building physics, and all related fields, allowing us to:

- reveal research findings,

- exchange opinions and gathered experience,

- present new ideas, technologies, and materials,

- introduce local and international contacts and cooperation.

In 2018 55 papers have been accepted by the Scientific Committee to be included in conference proceedings and presented during the conference.

Conference organizers would like to thank:

- all the participants for their decision to write and submit the papers and take part in the conference,

- the active members of the Scientific Committee for paper review,

- the inspiring keynote speakers,

- the sponsors for their support,

- the media sponsors for spreading information about the conference.

ENERGODOM 2018

Organizing Committee

List of Reviewers are available in this PDF.

All papers published in this volume of IOP Conference Series: Materials Science and Engineering have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

The paper describes the process of defining the requirements for renovation of single-family residential buildings to the nZEB standard in Polish conditions. According to the survey results the nZEB renovation standard should include only two indicators: energy need for heating Q_H expressed in kWh/(m² year) and percentage reduction of the primary, non-renewable energy Q_P demand. Process of defining the requirements was divided into two stages: calculation of cost-optimal heat transfer coefficients for renovated elements of building envelope, calculation of cost-optimal renovation standard of the two single-family model houses. The analysis was made for three Polish cities (coldest, medium and warmest) and for 5 different energy prices. As an optimizing criterion the minimum cumulative cost was used, calculated for the 30-year time-scale for different variants of renovation.

The Recast of the Directive on the Energy Performance of Buildings (the EPB Directive) came into force on 9 June 2010. One of the main requirements of the directive is to set a definition of nearly zero energy building (nZEB). Most of the EU member states have already set a definition of nZEB for new buildings and some of the countries also done it for existing buildings. The measures of thermal retrofitting of a dormitory to nZEB standard are presented in this paper. As there is no definition of nZEB for existing buildings in Poland, the paper presents a considerations of such a standard. Next, a set of thermo-modernization solutions are presented on a basis of existing building of a collective residence. The aim of the paper is to present the barriers that occur in such projects and solutions that can be applied to achieve the set goals. Building chosen for analysis is under historic protection which makes the work even more difficult. It was proved that used solutions were chosen not only to reduce energy demand or increase energy production from renewable energy sources, but also to increase thermal comfort within building.

LCC procedures are commonly used in building retrofit interventions for the evaluation of the costs and benefits of different solutions. LCC methods are also commonly applied to energy retrofit interventions according to UNI-EN 15459. However, these procedures can give significantly different results in relation to the methods used to define the economic and technical parameters used in the calculation. Several authors have highlighted how the uncertainties related to the quantification of the costs of initial investment and maintenance, the economic scenarios (inflation and interest rates), the costs of energy and labor and the "service life" of the components strongly influence the results and the assumption of different data sets can result in significantly different results. Several authors pointed out that it is necessary, prior to these procedures, to perform sensitivity analyzes, useful for understanding if and how each of these parameters can influence the results, which leads to the need to use probabilistic methods. The study reported here analyses the influence that different assumptions about the service life of building components have on the economic benefits brought by interventions of energy requalification. Specifically, through a specially developed probabilistic procedure, the influence on the global costs of different assumptions about the probability distributions and the specific parameters characterizing each of them related to the service life of components useful to realize the thermal insulation was evaluated. the envelope of existing buildings. In particular, four different probability distributions (normal, uniform, left triangular, right triangular), different values of the median have been taken into consideration for the same distribution amplitude and the global costs and the return time values have been evaluated. investment considering different alternative economic scenarios for inflation and interest rate.

In the article there was introduced an idea of NZEB constructed from large size wall elements mounted with dry connection and horizontal joints filled with polyurethane mortar. The proposed element was 50 cm thick with set of layers made of styro-concrete with EPS re-granulate and EPS-032 separation layers. The result was a solution with high thermal isolation and traditional division for construction and isolation zones. Additional elements of the system are layered lintels and intermediate moldings with increased pressing strength. The material solutions of the system elements are the effect of combined construction and thermal analyses.

This paper presents an optimal method of choosing a primary energy ratio, depending on the solutions regarding the building's technical equipment. A global cost method was used in the analysis, as that method allows for determining the requirements in relation to the type of the building and the way of energy supply. Analysis regards five –storey building, where 4 floors were repetitive. The building represents a standard of the collective residential buildings. 4 chosen scenarios were analysed: basic one (thermal protection requirements following the requirement valid in Poland in 2008 – SEB), presently valid (including a modernisation helping to fulfil the actual building rules) – SEB*, low energy building – LEB and passive building standard – VLEB.

Slowing development of low energy buildings in Poland and other EU is the lack of recommendations, compliance with which would guarantee the achievement of specified energy level. An attempt of a comprehensive approach to such a standard was made in 2013 by a program and the subsidy system for passive residential buildings. Two energy requirements were defined (NF15 and NF40) with appropriate specifications for building assemblies and installations. The maximum of the energy consumed during the heating season was specified as well as limits for other energy use. This publication is the first of two articles on the assessment of selected characteristics of several buildings with a reduced energy demand, which were built in north-eastern and central Poland. It is an introduction in which the assessed buildings were characterized both in terms of their designed technical and functional parameters as well as real energy supplies related to their heating and ventilation.

This article is the second of a two-part cycle describing the assessment of some characteristics of selected buildings with a reduced energy demand that were built in northeastern and central Poland. Two low-energy buildings (built in 1999-2001) and several buildings of NF15 and NF40 class were analyzed. Projected demand indicators for useful energy of these buildings range from 10.4 and 14.6 kWh/(m²·yr) for NF40 to 30,2 kWh/(m²·yr) for NF15. One the most important factors affecting the efficiency of low-energy buildings are: thermal quality of the housing and its tightness. This paper presents the results of the tests carried out to verify design assumptions, in particular thermal insulation of partitions, weight of thermal bridges and air tightness and its impact on the energy demand for heating and ventilation.

The paper describes impact of solar energy on a standard new building of a low energy consumption for space heating, and shows a problem of overheating of such a building in summer, that occurs quite often nowadays in moderate climate. The paper presents how important is to analyse in details the solar energy availability for a building envelope, especially for glazing of different orientation and inclination. Impact of solar energy on the energy balance of a building is analysed. Results of numerical simulations of dynamics of a building and its surrounding are presented. The focus is put on monthly changes of the space heating and cooling energy needs for every month of the averaged year – with regard to the solar energy influence depending on the different orientation of the rooms of a building. It turns out that cooling demand previously very small, now can become very significant and can dominate the total energy demand of new buildings, especially for some location of rooms and apartments. The results of simulation studies presented in the paper indicate necessity of changes in existing regulations on determination of energy performance of buildings, especially for certification of thermal energy performance of residential buildings.

Thermal performance of a brick wall after retrofitting is investigated by means of computational modelling of coupled heat and moisture transport. In the first step, temperature and moisture distribution over a reference year (Prague) is estimated, being subsequently used for the calculation of heat transmission through the envelope. Then, the annual energy balance is expressed. The simulations are carried out using both reference material parameters and weather-affected data of the brick. The comparison of results indicates that weathering may have a positive effect on the thermal performance of brick walls as it can contribute to a decrease of annual energy balance by ~ 2%. It means that this change can be considered on the safe side, without a risk of overestimation of thermal insulating capabilities of brick walls after retrofitting. The thermal assessment of several retrofitting alternatives reveals that hydrophobic mineral wool applied on the exterior side presents the most favourable option.

The paper focuses on theoretical analysis of physical determinants affecting construction of envelopes for wood-based structures in the intentions of sustainable development under the current and expected legislation in Slovakia after 2020. It deals with the optimization of model building envelopes in terms of heat loss according to the requirements of the Europe 2020 Strategy and consequently calculates the values of the fire resistance considering Eurocode 5. It assesses the application and fire safety of analysed envelopes in construction of buildings with a combustible construction system, i.e. wood-based buildings intended for housing and accommodation, in accordance with the Slovak legislation. The paper also concentrates on the optimisation of built-in thermo-insulating and facing materials of wooden load-bearing members in the model building envelopes in terms of the environmental burden throughout their life cycle and the impact on the resulting fire resistance. It assesses the possibilities of using building components made from recycled materials in the construction of timber buildings as a full-valued replacement of standard building materials from non-renewable sources.

Computer programs allowing determining accuracy of building design in advance, or its parts, from the thermal engineering point of view are on the rise. Finding the most suitable project design for optimizing future energy performance of building significantly contributes to implementation of European Directive on Energy performance of buildings 2010/31/EU in Slovakia. Using simulation software, DesignBulder in this case, became a very useful tool on the road to energy effective design. In this paper, we have placed a virtual family house (which will be built in Kosice, Slovakia) to the simulation software DesignBuilder and were finding out the most suitable design in case of future heating demand. Family house was designed taking in account architectural, environmental and constructional requirements of today's directives focusing on energy performance and energy efficiency. Results of this project are displayed in numbers as well as in graphic figures. Our goal was to find out the difference between two different types of envelope wall insulation.

The ETICS comprises a prefabricated insulation product bonded to the wall or a combination of adhesive and mechanical fixings. The insulation is faced with a rendering consisted of one or more layers (site applied), one of which contains a reinforcement. Adhesives used for bonding the insulation to the wall and base coat include cellulose ethers. These chemical compounds are used in building materials as thickeners, binders, film formers, and water-retention agents. Cellulose ethers influence on the physico-mechanical characteristics of a mortar. Temperature application and then conditioning of adhesives strongly affect the water retention. This paper presents a study on the impact of different temperatures on the setting and hardening adhesives with three types of cellulose ethers (HEC, HPMC and HEMC). The tests included water retention in freshly – mixed mortars and bond strength between the adhesive and substrate in mortars. Water transport in freshly-mixed mortars containing cellulose ethers were examined with classical and new methods Time Domain Reflectometry. During the laying and curing time the ambient temperature was hold on to 5±2 °C (reduced), 23±2°C (standard), 30±2°C(increased) in the relative humidity 50±5% or 80±5%. Adhesives were cured for 4 weeks. The pull-off test was performed on the following samples: without supplementary conditioning (dry condition) and after immersion of the adhesive in water for 2 days and 2 h drying at laboratory conditions. The tests were performed on the substrates: a smooth concrete slabs and the expand polystyrene insulation boards. The hygric properties were measured in the sample thickness 12 mm and 9 mm during the first 24 hours.

Massive walls exposed to external climate are characterized by low levels of thermal insulation. Unfortunately in many cases, due to the historic character of the building, the only possible way to improve their thermal insulation is the use of internal insulation. However, such solutions are associated with the risk of frost damage, mould growth or interstitial condensation. Calculations regarding the occurrence of these risks require complex calculation methods. Therefore, in the present work, the evaluation of the hygrothermal behavior of the internally insulated solid brick wall was performed based on the numerical simulations using the program WUFI Pro. Various material solutions of internal insulations, based on both synthetic and natural materials, were compared. The focus was on a particularly sensitive interface between the insulation and the original wall

In recent years, overheating of buildings during the summer has become a serious problem. This is the result of a significant increase in the number of cooling degree days over the last thirty years in Europe. As a consequence, increasing energy is consumed by buildings to keep the temperature at a relatively low level in the summer. This prompted us to examine the thermal simulation performance of a typical 50m² flat with different loadbearing materials used for the external walls. Calculations were made for lightweight cement composites aerated with air-entraining admixture or with the addition of aerogel particles. The results were compared with those obtained for walls based on conventional materials. Simulations were carried out using the Wufi Plus software. The components had a variable width of thermal insulation so that thermal transmittance of all the tested walls was constant. This assumption made it possible to evaluate parameters related to the thermal accumulation of the tested walls. These results demonstrate that the use of lightweight cement-based materials not only improves the thermal insulation of the whole building, but also significantly increases thermal mass of the walls. As a consequence, these type of wall component improve the microclimate, i.e. by lowering the internal temperature of buildings during the summer.

Ceramic bricks belong to the oldest and most used building material since the ancient ages. Notwithstanding, this favorable building material passed through many improvements and currently used ceramic brick is substantially improved compared to bricks from ancient production. The contemporary demands are paid especially on the mechanical resistance, high vapor permeability, outstanding thermal insulation properties, thermal accumulation function and noise insulation. On this account, the hygrothermal properties of construction detail composed by a contemporary lightweight hollow brick together with window lintel is investigated within this paper. Compared to laboratory methods aimed at the measurement of small samples, the semi-scale analysis represents a valuable approach for building materials testing. For this purpose, a system composed of two climatic chambers separated by the connecting tunnel with desired building construction detail is used. The brick block and window lintel is placed in a chamber connection tunnel, thermally insulated by mineral wool to ensure one dimensional transport and studied in sense of loading by real climatic data from Czech Republic. This valuable analysis allows long-term monitoring of the wall cross-section temperature and relative humidity profiles of particular elements in real scale. The obtained results represent valuable information for the practical application of the studied brick block in building practice. Such comparison allows optimization of building envelopes in order to improve their energy efficiency.

Sustainable building is construction approach which is friendly to both humans and the environment, saving natural resources and counteracting pollution. The most essential design and execution features in this kind of construction approach include: the use of renewable energy sources to preserve natural resources; lowering the energy consumption of technological processes; decreasing the amount of material waste (by changing or modernising the building material technologies used); limiting of energy consumption of existing buildings and those being designed; modern installations in buildings; computer aid in sustainable building design.

This paper presents principles for the design of external partitions and their joints using innovative thermal and insulation materials regarding their thermal and humidity requirements. Integral design elements in this range include certified computer programs which use numerical calculations allowing for parameters of external and internal air. The introduction of new thermal and insulation materials has a crucial impact on processes inside partitions and building joints. That is why the choice of a material layers system should be based on individual calculations considering 'the specifics of the situation in which it will be applied. Based on the performed calculations and analyses, certain recommendation regarding design and execution were formulated in this paper for design of low energy buildings.

Energy performance of opaque elements of building envelope can be improved by the decrease of heat losses by conduction or by effective utilization of solar heat gains. Enhancement of thermal insulation by application a thin layer of phase change material as an external finishing coating contributes to the attenuation and delay of heat flux transferred through partition. Based on the real scale experiment of one-year measurements, dynamics of temperature fluctuations in thermal insulation covered with external layer of PCM was characterized and analysed. It was concluded that outer application of PCM contributes to the attenuation of temperature fluctuations of the whole wall component.

The article discuss performance of the innovative building materials used for external walls in a case study construction objects. Following the targets of EPBD directive all new constructions shall be nearly zero-energy buildings (NZEB). In this framework the goal of façade elements proposed is therefore to achieve or undercut a thermal transmittance of 0.20 W/(m²·K). An assessment of the thermal behaviour of the innovative composites elements was carried out considering the physical and thermal properties. The goal of investigation was to confirm that the results obtained in a laboratory can be successfully transferred to demo-case buildings taking into account thermal and mechanical behaviour of the façade elements. The results are presented in the paper.

Recent technological advances in transparent insulation materials' (TIMs) production may have opened ways for new integration of these materials in buildings. This paper presents a study analysing several variants of façades incorporating TIMs on solar façade principles. The analysis is based on ongoing long-term full-scale experiments in Brno, Czech Republic. The paper introduces the test platform which is used for evaluation of specific aspects of integrated polycarbonate TIMs. The paper describes the experiment results, especially long-term thermal response and passive solar gain data. These data are applied for analysis of: influence of various polycarbonate-based TIMs on the real performance of the façades; influence of implementation of different solar absorbers on the performance of the proposed facades; effectivity of application of latent thermal energy storage (based on PCMs) as a part of heat accumulation layer and coupling of TIM with prismatic glass to enhance optical selectivity aspect. Presented results demonstrate for example significant influence of the type of solar absorber on the thermal performance of tested solar facades: the difference is up to 35% to 54%. Also the integration of prismatic glass coupled with simple two-wall polycarbonate panel can reduce solar penetration through components at the level comparable with the most complex six-wall panel.

This paper deals with measurement of three windows suitable for low-energy or passive houses. Windows are evaluated since 2011 in the laboratory of pavilion type with constant indoor boundary conditions and real outdoor climate. There are three windows, one wooden and two plastic which differ from each other by use of thermo modules inside the frame and center seal. Temperatures and heat fluxes on the glass, sash and frame of the windows are measured continuously. Outdoor climate is measured by the mobile weather station. During the measured period - winter 2017, windows were equipped with more sensors for temperature measuring than before. Sensors were added on the glazing, on the jamb, into the space between frame and sash and also on the montage gap filled with polyurethane foam. Temperatures on the same places of different windows are compared in this paper.

Several studies highlight the significant differences between theoretical energy consumptions, - considered in the Energy Certification Schemes (ECS), following the Energy Performance of Buildings Directive (EPBD) -, and the actual energy household consumptions, obtained from extended surveys and monitoring campaigns, especially in Southern European countries. These differences are referred in the literature as "heating gaps". Actual consumptions are significantly unpredictable (depending on outdoor climate, income, energy prices, cultural habits, etc.), but, in most cases, lower than permanent heating/cooling assumptions, present on regulations. This inaccuracy may lead to the suggestion of inappropriate measures on ECS, for low energy-consumption dwellings. Inappropriate because the impact of the same measure on energy consumptions and thermal comfort is different for cases with a permanent heating behavior and cases without it, and because it may lead to hygrothermal pathologies and, finally, an economic mistake, as the real payback time of that measure will be higher than the one suggested, misleading economically more vulnerable households. A complementary approach for the evaluation of thermal performance in existing dwellings, considering intermittent heating scenarios is proposed, by the definition of the "Passive Discomfort Index" (PDI), complementary to the energy label. This index is quantified by the calculation of the temperatures outside the comfort range within the building, in realistic use conditions. A 19^th century building, located in Porto, was used to perform a monitoring campaign of temperature and HR to calibrate a numerical model, developed using an advanced simulation tool. It was then performed a sensivity analysis, comparing the energy label with the PDI value, for different retrofitting scenarios, mainly with different insulation thicknesses. The results show that there is no obvious relation between the energy label and the comfort conditions, for intermittent heating scenarios, among others, reinforcing the need of a complementary approach. This is especially important for existent buildings and for Southern European countries, where the "heating gap" is higher.

Progressive urbanization has a direct influence on both the local and consequently global climate. The spatial development methods of the area require the use of modern computer technologies that support planning decisions by key decision makers. Evaluation of the prevailing microclimate conditions in the external environment is possible using CFD software. In this paper were presented scenarios of the impact of changes in spatial development of the area covered by revitalization process in the most urbanized zone of Lodz. The changes proposed by the authors included two types of simulation input data, i.e. values determined for a typical meteorological year and values of meteorological parameters from the nearest measuring station – Lodz-Lublinek. PMV index enabled to evaluate the thermal comfort of human in an external environment. Conducted research has shown that the more effective solutions were scenarios based on a growth of the green area rather than introduction of water elements within the analyzed public space.

This article presents an analysis of energy demand for an office buildings complex located in Gdansk, Poland. The analyses were performed with advanced computer simulations using the Energy Plus software. Simulations were validated by comparing their results with the actual energy consumption data for one of the buildings belonging to the complex and information gathered from complex owner and technical office. The paper includes the effectiveness analysis of using various sources and distribution systems for heating/cooling, use of the phase–change material as internal ceiling layer, reflective glass application and use solar energy produced by photovoltaic glass and PV panels located on the roofs. For each of the variants, thermal comfort analysis was carried out. The aim of the analysis is to examine the time variation and peak load reductions of power demand for the considered variants, indicated as possible to be introduced by the complex owner.

An opinion about the difficulties with maintaining appropriate climate conditions in the sports facilities is quite popular amongst sportsman of various disciplines. The problem can result in health and economic problems. First of all, the users of facilities are not provided with appropriate conditions for sport practicing and thus it may lead to contusions. Secondly the cost of using the object rises. Taking into account the increasing number of sports facilities, maintaining of indoor thermal comfort of them, while ensuring low maintenance costs, gains in importance. The paper presents the research conducted in a pneumatic tennis hall, a detailed analysis of maintaining thermal comfort in the hall and cognitive and utilitarian conclusions.

The need for reference files resulted from the development of advanced simulation models. Few methodologies for creation of test reference years were developed in last decades. Most common are following two methods: a simple selection of worst year from recommended period or the numerical analysis of months and then the combination of months into one reference file, which in is not real, because the months are selected from various years. It is necessary to temper the connection of individual months. With the outdoor climate change and therefore the synthetically (combined) based reference years for many areas can not satisfy more and more advanced simulation models. Reference years are created from values measured mostly by weather stations belonging to the national weather forecast service, which is not very dense and the resolution and measured climate data are insufficient. Problems of urban heat islands in the cities is also widely discussed. In this paper, the outdoor climate characteristics measured by the mobile weather station located in the University of Zilina campus are analyzed. The station records most of the climate parameters required for HAM simulations since 2014. Measured data are also compared to data obtained from national weather forecast service stations located nearby.

The main aim of preventive conservation, ensuring protection of historic collections, is stabilization of relative humidity, and for some materials also temperature, in the interiors of historic buildings or museums. The improper microclimatic parameters may cause irreversible damages. On the other hand, strict control of indoor climate is expensive. Definition of optimal microclimate control in terms of energy use, taking into account most important, sometimes even contradictory factors, requires interdisciplinary cooperation, among others in the field of conservation, collections' care, architecture, building physics and HVAC systems. Due to the type of historic objects and specific microclimate requirements, hygrothermal simulations of whole historical buildings are essential for the most part of a case study. The paper presents an analysis of energy consumption according to various microclimate control scenarios for The National Museum in Kraków: The Gallery of 19th-Century Polish Art - located in Renaissance Cloth Hall in Kraków (UNESCO World Heritage Site). The analysis is based on the results of simulations performed with WUFI®PLUS software and in situ measurements. The microclimate control variants were developed, among others, on the basis of ASHRAE and ICOM-IIC guidelines. The research was supported by The Polish National Centre for Research and Development within "HERIVERDE" project.

At present, administrative buildings consume more energy than in the past, and they also contribute to environmental pollution. It is an effort to build buildings with minimal energy consumption. The energy consumed to operate the ventilation air is not insignificant. Techniques and control systems allow different ways of saving energy. However, all the savings measures should also take into account the quality of the internal environment for the health of people. This article compares a ventilation system with a constant flow of ventilating air with an air-conditioning system with varying air flow rates ensuring the required air quality.

The article presents measurements carried out in an office room using metabolically generated carbon dioxide. The measurements were conducted using concentration decay gas tracer method. Increase of the concentration of CO₂ in the room occupied by workers allowed for evaluation of internal air quality and thermal work conditions. Analysis of the CO₂ concentration decay conditions after leaving the space by users was used to determine the efficiency of ventilation system and room envelope airtightness. The obtained results were used to calculate specific airflow rate of natural ventilation system being used in the analysed room.

The analysis of inner climate parameters and energy use was carried out in the Krasinski Palace in Warsaw: seat of The Polish National Library. The building includes books stores, conservation workshops, reading rooms and offices. Central hydronic heating system and sporadically used local air dryers are the only active systems. The purpose of the analysis was to check at which extent actual microclimate and energy management can be improved. Several alternative scenarios, not compromising climatic protection level of valuable collections, to optimize energy use were elaborated. It turned out, that only improving of heating control and doubling of thermal insulation thickness of ceiling to attic allows for up to 30% of energy savings. Application of extended HVAC systems is not necessary due to high hygrothermal inertia of the building. WUFI®PLUS software was used for the building simulations. The calculation model was first validated against energy use for heating and inner climate measurement results. A special module was used to account for moisture exchange between books and inner air.

Tracer gas dilution decay method is a convenient tool for measurement of actual air exchange in building. The article presents the results of measurements of natural air exchange in the selected, airtight rooms. A two-point and multi-point method were used to collect data and calculate the results. The standard procedure for the selection of the optimal measurement time was also included. In tight spaces with low air exchange, the measurement results depend on the assumed duration of measurements. It was found that the duration of measurements of several hours and the multipoint method allow to obtain convergent results.

The analysis and non-stationary numerical calculations of in situ temperature measurements are important details with regard to the connection between a window and a window sill. Due to its material and geometric heterogeneity, this connection is significant in terms of both surface temperature and heat flux. The structure under investigation is a panel fragment of the outer shell of an experimental chamber for in situ measurements. The aim of this paper is to compare the temperature obtained both from measurements and numerical calculation. Simulation and experimental measurement obtained in different environments, such as indoor and outdoor climates or experimental chambers, is an effective scientific tool for predicting the physical properties of building envelopes.

The intelligent building of Research center was built during 2014 and 2015. Fragments of its envelope meet the requirements for passive buildings. This building is a part of the University of Zilina campus, located in Zilina, Slovakia. It consists of a high-rise part with five story and a low-rise part with laboratories. Several laboratories of departments are also in the high building. What makes the building unique are several things such as three different heating systems, use of renewable sources, soil heat accumulator, various photovoltaic panels on the roof, vacuum collectors etc. All these technologies can be compared to each other and their efficiency and suitability for different purposes can be evaluated. In this paper, a unique façade monitoring system with 36 façade meteorological stations is described. Each of these stations measures outdoor air temperature near the façade, solar radiation, wind velocity and direction in a short time interval. Recorded values can be used for a more precise simulation of energy consumption, natural air ventilation, HAM simulation, wind-driven rain calculation and also compared to other simulations.

Initial design decisions regarding building external envelope may have important consequences for thermal comfort and total energy demand not only for heating but also for cooling. Before reaching for more energy-intensive solutions, effective use of passive measures to avoid overheating is necessary. In the article, special attention was paid to the influence of external wall structure on space overheating. On the basis of monitoring results it was found that the standard thermal insulation prevented excessive energy conduction into the space on very hot days and it should not be considered as a barrier for heat dissipation. The standard opaque wall was also compared with the uncovered transparent insulation, which is in summer an intensive source of energy gains. The basic dynamic characteristics of the monitored wall were analytically analysed by means of the periodic waves method.

Radiators, as the primary devices used in space heating, cover a fundamental role in the energy efficient use of buildings. In the search of an optimal configuration, from both energy consumption and thermal comfort viewpoints, comparison of different types and emitter size is crucial. However, an ideal heater with the highest maximum heat emission efficiency that can be used as a baseline still needs to be defined.

This study contributes to the development of the heat emission standard EN 15316-2-1:2007. We perform an analysis of heat transfer in enclosures with a 21- and 10-type panel radiators, using an ideal convector as a reference heater. Accounting for room side effects of thermal radiation, we compute the induced operative temperature both analytically and numerically. The numerical simulations are carried out for a European reference room specified in the CEN TC130 standardisation committee, introducing a number of assumptions for defining the benchmark radiator. For instance, back wall losses are neglected for ideally isolated emitters.

First we find that, contrary to what might be expected, the convector is the worst performing heater. On the other hand, studying analytically the operative temperature as a function of radiator type and size, we identify the most performing heater in the 10-type.

Furthermore, our analytical solution highlights a simple predictive method for computing the operative temperature for any panel size, in complete generality. As an example, we provide a series of analytical formulas for calculating the operative temperature of the radiators addressed in this study. The results of this work therefore provide a useful background for a precise and rigorous definition of an ideal radiator.

Water and air they mean life, but their quality represents our health. The main aim of the article is to introduce our research project "Hygienic Water audit scheme as a tool in the fight against Legionella" in terms of specific requirements from companies to minimize the energy efficiency for elimination of microbiological contamination of water supply and air conditioning systems (replace thermal disinfection by another effective method). The issue of water contamination, resp. air of Legionella pneumophila, its appearance and impact on the design and operation of water supply and air conditioning systems is relatively young. Little known problem in Slovakia has in the context of the European Union a serious position as it causes high mortality. The aim of the interdisciplinary research is to analyze the current state of hospital buildings, of the individual factors on a working materials and working environment in terms of their potential for microbiological contamination.

This paper presents results of a parametric study, which analyses the energy demand of a family house. Assessed house has various shape factors and the thermal-technical properties of the building envelope. Also the recuperation unit and the heat source is taken into account. The house in the first case is a one story bungalow, the next version is a partly two story house and in the third case it is a complete two story house. Each of these geometric variants is calculated for four various building envelopes, which are considered for different energy performance standards including low energy and passive standard. Air exchange rate is considered according to the Slovak standard as natural or mechanical with use of recuperation. As heat sources are considered gas, heat pump, pellets, electricity and wood. Also two combined sources are analyzed: gas and pellets with solar collectors for preparing the hot water. The results are analyzed according to the Slovak standard and directives, which are in terms of delivered energy, primary energy and CO₂ emissions.

Buildings, on average, account for approximately 41% of total energy consumption in the European Union. This energy consumption also translates into hundreds of millions of tonnes of emitted CO2 and other air pollutants. Due to a large share in the total energy consumption, the buildings sector has a significant potential to reduce the energy intensity of building operation, increase the share of renewable energy sources (RES), and thus significantly reduce emission of air pollutants. Existing buildings in Poland, both residential and public, are characterized by high potential in terms of energy and environment. One way to improve the energy efficiency of existing buildings and reduce emissions (in particular greenhouse gases) is through thermos modernization which adapts existing buildings to current and future energy demand requirements. The paper presents the expected environmental effects of measures which adjust the existing residential buildings to the requirements in force in Poland since 2021. It has been assumed that the energy demand for heating buildings will be limited to 55-60 (kWh/(m²year)). The calculations show that such measures will result in a reduction of total air pollutant emissions from households due to the reduction of energy demand for heating of dwellings from about 30% to about 67%, depending on the type of pollution.

The paper describes a method of design of storage tanks volume for an ice resurfacing machine in ice rink by using heat source with small thermal power (idea of downsizing). The main aim is to minimize investment costs for boiler room (the heat pump water-water). The achieved results show saving of investment costs about 35%. The request is the minimum water temperature at the value of 45°C before each filling process of resurfacing machine. Therefore it is very important to design the storage tanks volume where the water temperature will not be below the 45°C before the each filling an ice resurfacing machine during the hockey match or training. The required volume of storage tanks was calculated at the value of about 2000 litres if there is used the heat source with thermal power 45 kW. The number of storage tanks is given by boiler room dimensions too. In this case 3 storage tanks were designed.

Industrial halls are usually subjects to high energy demand. It is due to the many manufacturing processes, lighting, and the corresponding amount spent on space conditioning. The industrial buildings is one of the heaviest consumers of energy. Natural daylight is a vital element in our daily life. Providing natural daylight into the working environment is of fundamental importance for the comfort, efficiency and safety for the people in that environment. This paper deals with visual comfort evaluation in selected hall. Its calculated by the radiance simulation program.

The paper presents comparative analysis of daylight conditions in office room simulated with two techniques of sky and surrounding modelling. The luminance distribution in the surrounding environment was determined using CIE standard sky model and image based lighting (IBL) technique. In IBL method the sky and surrounding environment was defined by high dynamic range (HDR) image. Used HDR images were captured by camera with fisheye lens with 180° viewing angle which enables the projection of the entire hemisphere of the sky and surrounding environment. Determination of daylight conditions were performed for two days characterised by overcast sky conditions. Simulations were conducted using Radiance Lighting Simulation and Visualization software. Obtained results show differences in luminance and illuminance distribution in analysed room for both techniques of sky and surrounding modelling. Reason of the observed divergences is uneven cloud layer distribution at HDR images and influence of surrounding environment visible at HDR images. IBL technique allow more precise modelling of daylight distribution, especially in urban environment where surrounding buildings and vegetation significantly effect on the light availability.

Modification of a glazing unit by application of PCM layer can lead to the increase of the heat capacity of the component and effective control of solar heat gains in buildings. The purpose of this study was to investigate the effect of the PCM layer on total solar and visual transmittance in solid, mushy (transition) and liquid state of PCM. The experiment was conducted in laboratory scale using triple glazed window unit sample and artificial sun as a source of solar radiation. The transmittance (total and visual) was calculated based on the results from pyranometers and illuminance meters taking into account the intensity of solar radiation at the level of 1000 W/m². Measurements revealed that the component is almost blind in the solid state why in the liquid the transmittance is lower than for empty - traditional triple glazing. The transmitted radiation (total and visible) depends on the location of PCM layer (internal or external window chamber). The registered total solar radiation obtained in solid state was even 0 W/m² (when material was on the inner side), while the maximum values for liquid was 142 W/m² (material is located on the outer side). The light transmittance for more transparent case was around 1.6 klx and ten times higher in liquid than solid state.

Neighbourhood noises in newly erected residential buildings are problems which are more and more frequently raised by their inhabitants. Pursuant to the binding European norms, the way of testing acoustic insulation properties has been standardized, however both required values and indices used to express them remain at the discretion of individual countries of the European Community. In the article, single-number acoustic insulation indices for air sounds used in Europe are presented and the methods of converting them are described. Current national requirements concerning acoustic insulation properties for interior walls within the apartment and between apartments in multi-family buildings as well as their comparison with requirements applicable in selected countries of the Western, Central and Southern Europe are presented. Based on the provided data, the evaluation of national requirements regarding acoustic insulation properties for interior walls was carried out. It was concluded that Polish acoustic requirements for interior walls are at a low level not only compared to the countries of the Western Europe, but also Central and Southern Europe.

During the renovation works one of the apartments, in a tenement house in the center of Cracow, we had the opportunity to conduct measurements of airborne and impact sound insulation of existing and newly designed floors between apartments (before and after replacing the floor layers). Article presents results of these measurements along with the analysis of floor solutions used in the interwar period and the comparison of their effectiveness with solutions used nowadays.

The building occupant energy related behavior modelling is a key factor for building performance simulation that supports realistic forecasting of energy consumption. The current state of development of this topic delivers partial knowledge about occupant's behavior, but information about transient thermal comfort of each occupant is still, beyond the reach. Access to such a data would visualize outcome of the proposed HVAC design. With a use of proper measurement technique, it is possible to develop virtual bot that will recreate typical energy related behavior scenarios inside designed building and gather consistent information regarding thermal properties of the indoor environment. Such a tool will display potential faults of the design regarding occupants thermal comfort and point out potential paths of adjustment during design phase

The paper presents an analysis of the energy performance of single-family buildings with two zones differing in dynamic properties. The procedure currently applied for determining the energy performance distinguishes several cases in which a division into separate calculation zones is required, whereas none of them sanctions dissimilarities of dynamic properties between parts of buildings. In order to determine the differences resulting from the separation into zones, e.g. the ground floor with a heavy structure and a lightweight usable attic, the monthly balance method was used as legally binding for establishing energy performance of buildings. Heat demand for heating and cooling a building was determined. The results obtained for a building treated as one zone and divided into two zones were compared. The analysis was carried out in a variant manner, i.e. assuming varying internal thermal capacity, usable space, surface of glazed partitions, and air exchange rate, for 59 locations in Poland. It was shown that, under assumption of the same useful area of upper and lower storey, in cases taken into consideration the maximal difference in energy demand for heating only is 5.41% (Nowy Sącz), but in cooling can reach as much as 46.75% (Zakopane).

This article evaluates the results of heat and moisture analyses for areas adjacent to a window, mounted in various ways to an external wall. The parameters for the window were assumed to be constant. The calculations were focussed on evaluating the effect of installing a window in a wall and the influence of the wall's construction on the quality of the microclimatic conditions in the contact zone of these two components. The following variables were analysed: a partition without insulation, a partition with thermal insulation, with additional expanding tape and with additional aerogel mat. Each the variable was additionally diversified with respect to the location of the window within the wall. The influence of the material used for the load-bearing wall layer was also analysed in the simulations. The variables were modelled using CFD (computational fluid dynamics) software. For all variables, the cumulative value of heat flux and linear thermal transmittances were calculated. Additionally, distributions of the 0 isotherm were determined and the f_Rsi temperature factors were calculated. These results have been thoroughly analysed to determine the most beneficial solution that provides optimal thermal insulation and reduced risk of mould. Our findings can help ensure the maintenance of an ideal microclimatic conditions and reduced energy wastage in the contact zone of windows with external walls.

There are some difficulties in analysing the actual thermal state of a building under changing conditions of the environment, particularly solar insolation. The methodological approach to overcoming these difficulties and the corresponding mathematical models of the thermal state of a building are proposed. The base of the models is a power circuit in which there are described all components of heat losses and heat revenues. Controlled and uncontrolled heating systems are considered by representing heating devices as a source of effort or as a source of flow. The proposed models as a result of the analysis of the thermal state allow obtaining energy indicators of the building and an objective picture of the thermal comfort in the rooms simultaneously.

The main goal of our research was to find relationships between building parameters and their importance to building energy efficiency. We developed a numerical model, which generates data describing single family houses with different, random sets of parameters. The collections include: building geometry, facade orientation, thermal properties of partitions, types and sizes of glazing, airtightness, types and sizes of unconditioned buffer zones. The model was used to generate a large amount of different building cases, allowing statistical analysis of building energy efficiency on an unprecedented scale. The research shows, that applying this method allows identifying relationships that would otherwise be very difficult to discover and describe, in particular by examining only existing buildings.

The paper analysed the 24 hour performance of a solar chimney placed on a building roof in Krakow, Poland. The solar chimney was an element of as a passive ventilation system allowing energy efficient night ventilation during the summer season. The chimney was built as an air duct. Three walls of the chimney were made of glass and faced toward the sun, the opposite wall was made of a concrete absorber. The system worked in two stages: day and night. The absorber located in the chimney was heated during the day, and cooled during the night. During the night phase, the released heat provided a draft contributing to passive ventilation.

Absorbers with different thermal capacities were studied. Simulations were conducted for three different absorber thickness 10 cm, 20 cm or 30 cm. The simulations were carried out using the Ansys Fluent simulation software. The hourly results of temperature distributions in the chimney allowed the authors to determine the optimal absorber thickness for the passive ventilation system. Calculations showed that the chimney with the absorber that was 10 cm thick was the optimal among analysed solutions. The absorber is warmed up to the highest temperature, up to 82°C, and induces air flow which lets removing even 3820 m³ of air during the night.

The purpose of the publication is to focus attention on the potential of vegetation application and revitalisation of non-industrial sewage and rainwater in contemporary architectural design. Use of plants, along with the natural water resources management system in the external zone of the building and in the public space, has an ecological justification, characterised by numerous advantages, making it easier for us to live in an urbanised area. These are: simplicity of implementation, thermal and acoustic benefits, energy saving, the possibility of using local plants, health and aesthetic values, as well as low maintenance costs.

Out of greenhouse gases causing global warming, CO₂ has the largest direct contribution after industrial revolution. To reduce CO₂ concentration, it is essential to collect CO₂ in the atmosphere and store it in separate places from the atmosphere. As a method of CO₂ capture and fixation, we studied a method using carbonization of wood. Based on the statistics of domestic wood production and import/export, we estimated possible amount of fixed CO₂ as 8 to 10% of annually emitted CO₂ in Japan. Influence of wood carbonization on CO₂ concentration in the atmosphere was also examined based on a prediction model for the atmospheric CO₂ concentration.

Shipping containers are currently one of the innovative trends of shaping architectural objects. They are used to build portable and permanently set in the ground residential and public buildings. Realization with the use of shipping containers appear all over the world, i.a. single- and multifamily houses in the Netherlands, Spain, Denmark and France, the bus station in the Netherlands, the art gallery in Tokyo. Particularly, many realization with the use of shipping containers relate to housing environment due to ease of transport, speed of installation and assembly, shorten the construction time and pro-environmental potential. In contrary, conventional housing is responsible for ¼ forest logging area, absorbs 1/6 of fresh water resources and consumes 2/5 of liquid fuels and materials. The respect for the environment in the aspect of the global direction of shaping residential and retail buildings is particularly important. This paper focuses on pro-environmental, usably and economical aspects of architectural objects with the use of shipping containers on the example of Polish and world-wide realization.

Green infrastructure needs to be where people live and work – everywhere in the city. Current city challenges such as hot, dry, pollution, traffic, housing, urban sprawl etc. can be solved simply with nature. Improving stormwater management, changing microclimate, windbreaks, reducing energy use, biodiversity, applying green roof are few examples of solving problems in the cities these days. Ecosystem services must come to towns and people need to learn to use them. Sponge city is not only new term. It provides ecological, economic and social benefit through natural solutions. It is a key to sustainable spatial planning, urban design and development. The aim of this paper is to explain a case study of Košice city how green infrastructure can solve climate petrubation.

The increasing awareness of issues like climate change and reduction of available fossil resources moves scientific research into the development of new technological solutions in order to reduce the energy and environmental impact of buildings. Hence, in recent years, key concepts such as energy saving and environmental sustainability affected both the design of new buildings and the retrofitting of existing buildings.

The present study aims to evaluate the energy behavior of an existing building in Mediterranean area, and to quantify the potential contribution provided by retrofitting solutions implying the adoption of green roofs and green façades. Dynamic simulations, validated by comparison with experimental results, show that a green façade with dense foliage allows a reduction by 1.7 °C in the indoor air temperature and by 1.5 °C in the inside surface temperature, if compared to a traditional retrofit solution for the envelope. Furthermore, the outside surface temperature is reduced by 2.9 °C, and the cooling load is reduced by 32%.

These results suggest that green façades are a viable solution to mitigate current environmental issues in buildings. Lower energy consumption corresponds to lower pollutants emissions and to economic savings in the use of the building.

Research and development in the façade engineering field highlights the need for comprehensive system solutions integrating advanced materials and renewable energy use. Presented study focuses on implementation of Transparent Insulation Materials (TIMs) in a façade concept. The idea is based on sensible use of (renewable) solar energy to reduce the heating demand of buildings. The concept integrates TIMs into a Transparent Insulation Façade (TIF) based on more common "solar wall" or "Trombe wall" systems enhanced with selective absorber (SA) functionalities. The study presents analysis of thermal, solar energy and environmental performance of the concept on a case study basis. Firstly, thermal analysis based on standard calculation is introduced to describe thermal and solar performance of the concepts. Secondly, energy balance calculations are used to compare the concepts with conventional façade systems. Finally, a Life-Cycle Assessment (LCA) evaluating the environmental impacts of the façade concept is introduced. The results show that the proposed concept performs better in both energy consumption and environmental impacts compared to a common facade with external thermal insulation. The TIF has higher heating energy demand than a common façade, however this is offset by up to 178 kWh⋅m⁻²⋅a⁻¹ solar heat gains. The difference in environmental impacts (up to 80%) is also in favour of the TIF.