Jan Tywoniak

Czech Technical University in Prague | ČVUT · Faculty of Civil Engineering (FSV)

The possible influence of anatomical sections of wood on mold growth was investigated by means of a laboratory experiment. The selected fungi, Aspergillus sp., Penicillium sp., and Alternaria sp. were inoculated by spraying on the surface of wood specimens prepared from pine (Pinus sylvestris) and spruce (Picea abies). The incubation was carried ou...

This paper informs about laboratory experiments studying heat transfer phenomena at the interior side of balcony doors. A well-insulated testing space representing a typical room with a balcony door equipped with floor heating and warm air heating was used. In the first step, an opaque panel with similar thermal transmittance as a triple glazed bal...

Paper deals with the roof windows (skylights) from building physics point of view. Based on several introductory analyses an innovative solution of the frame and sash construction was developed in close cooperation with the industrial partner. Resulting parameters correspond to requirements set for passive house level windows (minimized heat transf...

During the last few decades, unheated attic spaces (so-called “cold attics”) have been one of the most moisture-problematic spaces in the building practices of Europe and North America. Problems with such spaces are usually associated with condensation, frost formation, and mould growth on the lower surfaces of the roof deck. To solve these problem...

In this paper reporting preliminary results from the ongoing research, heat transfer phenomena at window surfaces and adjacent areas of the building envelopes are studied. In the first step, in-situ observation of balcony door based on indirect estimation of temperature distribution close to window surface was carried out by means of infrared imagi...

Wooden floors were traditionally used in brick apartment houses built at the turn of 20th century in many European cities. Thermal renovation of such houses often involves thermal insulation at interior side of external walls. Internal insulation makes microclimate in the vicinity of wooden beam ends colder and more humid. The real-scale experiment...

This paper deals with a small but important component in a building envelope, namely roof windows in pitched roofs. Building physics methods were used to support the search for new solutions which correspond to the maximum extent for requirements for passive house level design. The first part of the paper summarizes the key phenomena of heat transf...

On the road towards Low or Zero Energy Buildings (ZEB), both a reduction of energy demand and on-site electricity generation from renewable energy systems becomes necessary. Recently, Photovoltaics (PVs) have been widely used in modern buildings as part of the façade, mounted on the envelope or integrated as construction elements. This work investi...

This article deals with the hygrothermal performance of wooden beam ends embedded in brick masonry walls. The real-scale experiment involving three interior insulation systems with different water vapor resistances and different treatments of joist pockets was monitored for three consecutive years. The moisture load of test walls was controlled dur...

Electronic Book of Abstracts from Central Europe towards Sustainable Building 2019 (CESB19) held 2nd–4th July 2019 in Prague, Czech Republic, under auspices of iiSBE, CIB, UNEP-SBCI, FIDIC. *** Click on QR codes in the document to see open access full papers. ***

Solar PV shading devices are good solutions to control daylight and reduce the unwanted solar gains, while generate electricity at the same time. Since thermal, electrical and daylighting performance competing each other, it is imperative to consider specific design criteria to optimize and allow energy efficient level of thermal and visual perform...

The article focuses on the determination of a fungal growth range on plaster depending on external conditions. The experiments compare three types of plaster which are the most widely used in Europe. The selected plaster is two mineral and one silicone. These types of plaster are standard mixtures developed and donated by manufacturing company from...

This paper deals with a small but important component in a building envelope, namely roof windows in pitched roofs. Building physics methods were used to support the search for new solutions which correspond to the maximum extent for requirements for passive house level design. The first part of the paper summarizes the key phenomena of heat transf...

This work highlights the Building-Integrated Photovoltaics (BIPV) potential in two urban areas with different characteristics in the city of Prague. The representative building blocks were selected and the CitySim software tool was used for the assessment of the hourly irradiation profiles on each surface over a one-year period. Considering appropr...

The main objective of the present research was to develop a methodology for assessment of resilience of residential buildings in Central Europe. The main purpose of the methodology is to enable to set performance levels in terms of resilience for new multifamily residential buildings. The paper describes a method of selection and development of the...

This paper deals with hygro-thermal performance of wooden beam ends embedded in masonry walls with lime-cement plaster applied on the external side. Three different insulation systems are attached on the internal side of masonry. The real scale experiment has been monitored for three consecutive years. Microclimatic conditions in joist pockets were...

The paper contributes to the fulfilment of the environmental targets of the EU by introducing an innovative solution for envelopes of nearly zero-energy buildings (nZEB). It presents the development of an environmentally friendly alternative to aluminium curtain wall systems for new constructions or renovations. The research and development were fr...

The contribution evaluates the existing operation of the Open Garden in Brno, which was designed in a passive energy standard and put into operation in January 2013. After almost four years of operation, feedback from the users of the building was surveyed by questionnaires for summer and winter operation. The thermal comfort of the Predicted Mean...

Today’s stringent requirements on building energy performance and gradually increasing price of energy enforce complex refurbishment measures. Improvement of thermal insulation of building enclosure is the first logical step for climatic conditions of semi-continental climate. Refurbishment of many buildings with cultural value is possible only by...

The present research deals with a simple dipping method to insert octadecyltrichlorosilane (OTS) into cell walls of spruce wood and to deposit OTS layers on its inner and outer surfaces. Distribution and chemical interactions of OTS with wood polymers has been investigated by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-ED...

Dieser Beitrag befasst sich mit der Entwicklung einer Systemlösung für den Ersatz alter nichttragender Außenwände bei Nichtwohngebäuden aus den 1960er- und 1970er-Jahren. Die Hauptidee war es dabei, ein vorfabriziertes Produkt zu entwickeln, das moderne Holzprodukte verwendet, um eine Alternative zu üblichen Metallbausystemen anzubieten. Es hat sic...

In the present work, medium density fiberboard (MDF) panels were produced using multiwalled carbon nanotubes (MWCNT) reinforced urea formaldehyde resin. Response surface methodology was employed to optimize the relationship between the three variables, viz. pressing time, percentage of UF resin and percentage of MWCNT, used in the fabrication of MD...

Surface defects cause the measured tensile strength of alkali glass fibers to be significantly lower than their theoretical values. Coatings can be used to ‘‘heal’’ surface flaws and to modify surface properties. In the present work, the nanocoating on alkali-resistant glass (ARG) fiber rovings was carried out by self-assembled monolayers (SAMs) of...

Poly(vinyl) alcohol (PVA)/nanosilica (SiO2) based electrospun nanofibers has been deposited on wood substrate by means of the roll electrospinning process. The nanofibrous coating was hydrophobized by self-assembled monolayers of octadecyltrichlorosilane (OTS) via a sol−gel dipping process. The PVA/SiO2 nanofiber coating and OTS hydrophobized coati...

Buildings are responsible for 35% of greenhouse gas emissions released in Europe. The highest potential for reduction of the environmental impacts is in the existing buildings' energy efficiency improvement. The paper introduces a development of new methodology for a rapid deep energy retrofitting of existing buildings applicable to residential hou...

A relatively new approach for wood protection against fungal decay is based on hydrophobisation of wood and on lowering its moisture content. Water repellence of wood can be increased by polymerization of hydrophobic monomers in wood cell walls. It was found out that Norway spruce wood after treatment with octadecyltrichlorosilane (OTS) exhibited r...

This paper presents building design strategies for reducing embodied energy and embodied carbon dioxide emissions as developed within the International Energy Agency’s Energy in Buildings and Communities Programme. The design strategies are illustrated using three case studies of design optimisations of building elements, the building structural sy...

The natural fibrous materials are widely used as thermal insulator for building application. The thermal insulating performance of natural fibrous material are affecting by the high humidity and temperature. Due to high moisture in natural fibrous insulators, they are very susceptible for microorganisms attack as well as the reduction in the therma...

Der Beitrag befasst sich mit der Entwicklung einer Systemlösung für den Ersatz alter nichttragender Außenwände der Nichtwohnbauten aus den sechziger und siebziger Jahren des 20. Jahrhunderts. Die Hauptidee war, ein vorgefertigtes Produkt zu entwickeln, das moderne Holzprodukte benutzt, um eine Alternative zu üblichen metallischen Systemen anzubiete...

The paper deals with a development of system solution for replacement of old curtain walls at nonresidential buildings from 60ies and 70ies 20th century. The main idea was to develop a prefabricated system using modern wood products as an alternative to usual metallic solutions. The system of curtain wall at passive house level was successfully tes...

In general, building constructions containing wood elements are moisture sensitive. To increase the knowledge about their hygrothermal performance accompanied with assessments of risk of mold growth and other degradation mechanisms a set of analytical methods is typically used: standard calculation or more advanced mathematical models, laboratory m...

In 2013, a campus building in Prague, built more than 40 years ago, was partially refurbished. Its old curtain wall with very poor performance was completely removed and replaced by a new element façade of significantly higher quality, which meets today's recommendations concerning the energy efficiency. The comfort requirement was satisfied partia...

We have produced hybrid liquefied wood based polyurethane (LW-PU) and LW-PU/nanosilica hybrid coatings for wood substrates. The prepared hybrid polyurethane coatings were hydrophobized by self-assembled monolayers of orthotrichlorosilane (OTS) via sol-gel dipping process. The nanosilica addition into LW-PU system enhanced the physical properties of...

The paper describes development and evaluation of building envelope panel system based on advanced natural materials (thermally modified wood, laminated veneer lumber, wood fibre and cork thermal insulation). Properties of the product were proven by modelling, calculations and experiments inline with actual standards on curtain walls systems and in...

In many countries of Central Europe is a stock of existing buildings from 1950’s to 1980’s featuring original panel curtain walls. These envelope structures are now at the end of their service life and thus replacement solution is needed. There are various replacement alternatives such as aluminium, steel or steel-plastic panels, but these structur...

The paper describes an own development of a curtain wall panel system. The leading idea of the project was to prepare an alternative solution for replacement of old metallic curtain walls during the refurbishment of nonresidential buildings from the 1960's and 1970's. Presented solution use wood and wood based materials (laminated veneer lumbers) f...

The first part of this paper describes how a façade of a 40 years old campus building in Prague has been replaced. This replacement served as an impulse for a) a discussion about energy performance of a whole building, b) our own development work. As the replacement used quite high-quality curtain wall elements, the resulting situation in terms of...

The first part of the paper describes one already performed replacement of a façade of a 40 years old campus building in Prague. This fact was used is as an impulse for a) discussion about energy performance, b) own development work. Use of quite high quality curtain wall elements lead to a different picture in terms of energy performance of the bu...

Příspěvek představuje lehký obvodový plášť panelového typu na bázi dřeva. Tento prefabrikovaný prvek může sloužit jako náhrada metalických obvodových plášťů užívaných na budovách od šedesátých let dvacátého století nebo může být použit pro novostavby. Technické řešení vhodně kombinuje moderní materiály na bázi dřeva a vytváří obálku budovy, která z...

Czech Technical University in Prague (CTU) is building a new research centre UCEEB - University Centre for Energy Efficient Buildings nearby Prague in the town Bustehrad. The main research focus of UCEEB will be integrated approach to sustainable design and construction of buildings. The main mission of UCEEB is to deliver to construction industry...

Faculty of Civil Engineering at CTU in Prague has started regular education in sustainable building several years ago with the ambition to become a leading university in this branch in Czech Republic and to become one of the recognized universities teaching sustainable building at international scale. A brief overview about educational activities a...

This paper brings a brief overview about running teaching activities at the Faculty of Civil Engineering CTU in Prague dealing with sustainability agenda and its implementation to building design and construction. A new master study programme directly focused to the problem of design of sustainable buildings: Buildings and Environment will start in...

The paper brings an overview in sustainable building development in the Czech Republic. Specific natural, climatic and economy conditions for the development of sustainable buildings in CZ are shown, and influence of extensive economic transformation after 1990 is discussed. The paper shows selected examples of implemented sustainable approaches in...

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Correlations between rainfall amount and water content in coarse soils were studied. Situations were registered in which the intensity of the gravity-driven flow in the soil exhibited irregular oscillations which could not be explained within the scope of the standard Richards' theory. The problem was analyzed by means of a set of laboratory experi...

The most frequently used approach to the description of liquid transfer in porous media is based on its analogy with the diffusion process. It introduces effective diffusivity D(u) depending on actual moisture content u. On the basis of experimental data obtained by means of neutron radiography, it is shown that this function D(u) cannot be regarde...

The exact theoretical description of the evaporation from porous material is of great importance for many questions in the building research and practice. A very compact information concerning this process can be obtained from evaporation curves m-t (mass of the evaporated liquid-time) and their derivatives. In the article, the results of experimen...

The evaluation of the condensation-evaporation rate in external walls is based on the Czechoslovak standard but the physical picture of both transport processes is still incomplete. One of the prospective methods used in research is the technique of two-dimensional micro-models of the porous space which visualizes the comportment of the fluid. On b...

Republic, petr.moravek@atrea.cz Niedrigenergiehäuser bis zum Passivhaus-Niveau setzen sich langsam auch in Tschechien durch, was natürlich mit passenden Lüftungsstrategien verbunden ist. Der Beitrag präsentiert die am häufigsten benutzten technischen Systeme und diskutiert derer Eigenschaften und Akzeptanz. Die Anzahl der gebauten Niedrigstenergieh...

The paper deals with the earth-to-air heat exchanger (EAHX) simulation and monitoring. A newly developed hygro-thermal model for transient simulation of EAHXs has already been validated against an analytical solution; a comparison with performance data of real EAHXs has missed so far. The model is tested against long-term monitoring of two simple e...

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Nad názvem: Czech Technical University in Prague, Faculty of Civil Engineering = České vysoké učení technické v Praze, Fakulta stavební 150 výt.

"Katalog vydán k výstavě v Galerii Jaroslava Fragnera v Praze (29.10.-14.12.2008)"--Tiráž

Ed. 1. Na obálce nad názvem: CTU in Prague, Faculty of Civil Engineering 200 výt.