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The vision of the research project is to find an energy optimal building configuration, suitable for specified requirements and restrictions. The first step on this way is to create a measure to compare building configurations, faster than explicit energetic simulations. The current study examines the applicability of multivariate linear regression to support the solution of building optimization problems. During the study, multivariate linear regression models were created to estimate the expected annual heating energy demand of building configurations and examined their accuracy Between examinations, the models were modified so that the complexity was increased only to such an extent that the approximation was still sufficiently accurate. The result was a multivariate linear model that estimated the expected output for unknown descriptive variables with a 0% relative error and a 1.6% standard deviation. The R2 point of the estimates was 0.9884. Based on these, the model was considered applicable in the search space defined by the training patterns.

The design of the envelope in high-rise office buildings is a task of great importance as it can impact the entire building's energy performance. The study presented in this paper is an extension of a previous work reporting on the optimization of the façade and the shading systems of an east-west facing high-rise office building. This study aims to investigate the façade geometry design factors for other potential orientations, e.g., south, south-east, and south-west directions. The IDA ICE 4.8 complex dynamic building energy simulation program was used to assess thermal and lighting simulations. The optimization results revealed the best-performing façade configurations, appropriate for each orientation examined in terms of thermal comfort, visual comfort, and energy consumption.

The reduction of energy consumption is a major issue nowadays that should be considered during the design process. High-rise buildings represent a building type with significantly high energy consumption. They serve typically as offices with fully glazed façades, generating considerable energy demand. This study aims to optimize the envelope and the shading systems of a high-rise office building (Middle Europe). For this purpose, multiple façade variants were tested by assessing the thermal and visual comfort, as well as energy demand. The IDA ICE 4.8 building energy simulation program was used for thermal and lighting modeling and to carry out building physics calculations. Results revealed the best performing, optimized façade configuration in terms of comfort and energy efficiency.

About 800,000 of “Cube houses” which date back to the socialist era are still in use throughout Hungary. These houses are considered to be “outdated” and they bring not only energy but also social issues. This paper presents a refurbishment design solution for the cube house, combining vernacular architecture with modern solutions within the framework of Solar Decathlon Europe 19 competition. The paper investigates the comfort and energy improvement of the refurbished design. Thermal simulation results revealed considerable improvements, which can be considered and implemented to a big proportion of family houses with analogous dimensions, under similar climate conditions.

The aim of this paper is to present a solution for optimizing the operation of the Szentágothai Research Center. This building has several different functions at a high degree, so it can represent most of the difficulties in achieving an ideal level of operation energy consumption while assuring an adequate comfort level.As a first stage of a generic office building optimization research, a monitored reference building of common type was chosen. Various active operation optimization experiments were carried out. The successive reduction of operation intensity and schedules resulted in 63.3% operation energy savings. The results provide considerable potential in generic office design applications.

The purpose of this research is the application of a passive design strategy for office buildings, the wall-window-ratio optimization under moderate climate. A simplified thermal and lighting simulation model of an office research building served as reference testbed for thermal comfort, daylight factor and illuminance as well as heating, cooling and lighting energy demand assessment. These six performance types of similarly oriented room groups are evaluated via a self-developed weighting process to determine the orientation dependent optimal wall-window-ratio of all room groups. This multi objective optimization applies in a broad range of office buildings under moderate climate.

The optimization of high-rise office buildings' envelope and the application of energy-efficient measures have become a priority nowadays. Therefore, this investigation aims to assess the role of the façade's geometry design factors, e.g., folded façade perforation, window orientation, and window-to-wall ratio on building comfort and energy performance. The energy simulations were performed using IDA ICE 4.8 thermal simulation program to evaluate the thermal and visual comfort and the energy consumption of various façade test models. The optimization resulted in a façade model with a great level of thermal and visual comfort as well as a total energy reduction of 14%, representing a good compromise solution in the trade-off between thermal and visual comfort as well as energy efficiency.

During sketch design stage for the new block of the University of Pécs, Medical School comfort and lighting simulations were applied to quantify optimization strategies. Simulation cases about shading possibilities, façade glazing ratios and internal heat storage masses evaluate the impact of illumination, solar gains, loads and heat transmission on visual and thermal comfort. The goal was to select the most favorable comfort, coupled with maximum reduction of investment costs. Concepts represent 14% (shading), 10% (reduced wall-window ratio), 11% (slabs without suspended ceilings), and 17% (combined wall-window ratio and thermal mass) improvement in thermal comfort performance, and it was proposed for further design.

First Hungarian Active House refurbishment won the Active House Award and the Energy Globe Hungary prize in 2017. This paper provides insight into the renewal design process of the typical home from the 70’s under disadvantageous site conditions. Dynamic thermal simulations helped to gain insight into space organization and building envelope concepts and their effects on comfort and energy performance. The Active House Standard was applied to evaluate the calculation results. The most advantageous concept was selected for final design elaboration and construction. The implemented building proved that in the refurbishment process it is possible to achieve highest level of efficiency in operation energy consumption with positive yearly balance by simultaneously being able to rearrange the complete interior space and as a consequence the building shape and envelope into a competitive design at international level.

A building physics supported development was undertaken for the new block of the University of Pécs, Medical School. During sketch design stage climate, lighting and energy simulations were applied to quantify energy optimization strategies. Simulation cases assess the impact of shading technologies, wall-window ratios and thermal masses on used thermal energy demand. Based on a previous study about visual and comfort performance, goal was to identify the highest energy efficiency rates with maximum investment cost savings. Besides best comfort results, the most optimal development represents 9% saving in used thermal energy, and they were proposed for further design.

A huge portion of energy consumption in buildings comes from heating, ventilation, and air conditioning. Numerous previous works assessed the potential of natural ventilation compared to mechanical ventilation and proved their justification on the field. Nevertheless, it is a major difficulty to collect enough information from the literature to make decisions between different natural ventilation solutions with a given situation and boundary conditions. The current study tests the passive air conduction system (PACS) variations in the design phase of a medium-sized new winery’s cellar and production hall in Villány, Hungary. A computational fluid dynamics simulation based comparative analysis enabled to determine the differences in updraft (UD) and downdraught (DD) PACS, whereby the latter was found to be more efficient. While the DD PACS performed an air change range of 1.02 h−1 to 5.98 h−1, the UD PACS delivered −0.25 h−1 to 12.82 h−1 air change rate. The ventilation performance of the DD version possessed lower amplitudes, but the distribution was more balanced under different wind incident angles, thus this version was chosen for construction. It could be concluded that the DD PACS provides a more general applicability for natural ventilation in moderate climates and in small to medium scale industry hall domains with one in- and one outlet.

The yurt is one of the ancient living units for the nomadic cultural country. The yurt is a nomadic vernacular architecture, which has been developed for 3000 years. There are 31 counties ...

Residential sector represents the largest energy consumer in the city of Pristina, as a capital of Republic of Kosovo. This is also the most diverse sector in terms of the energy sources used for s...

Over the course of human history, vernacular architecture has developed according to the climate, culture, geographical conditions and lifestyle. One of the fascinating designs from around the worl...

The increase in the world’s population has been paralleled with high rates of migration to cities and rapid urbanization, which cause problems for city management and the environment. One of the great challenges in urban development is mitigating the effects of microclimate on the urban area. The goal of sustainability approaches is to adopt a new view of human, environment, and space to develop mechanisms that link all these elements within a balanced organizational structure of urban clustering. Urban renewal requires a multifaceted strategic approach incorporating both local and regional regulations, developed through multi-sector and multi-agency partnerships. Thus, sustainable urban renewal is a concept to integrate the global concept of sustainability into the urban renewal process. To transform such abstract concepts into real practices, an effective method should be worked out. This study applies the triple sustainable values system, i.e. economy, environment, and social equity into urban renewal projects in order to reduce energy consumption and create a comfortable environment in hot and dry climates. For this goal, a chosen district was analyzed and evaluated in city of Sulaymaniyah in Iraq, employing a field survey and questionnaires among local residents to identify the existing urban problem in microclimate. In this paper, a model proposes solutions for the study area to support appropriate strategies for sustainable urban renewal, transferable to other districts within the city or even to other cities with same climate in the north of Iraq.

Natural driven ventilation is a widely used technique in hot and arid climate, but it is rarely known that it can lead to significant energy saving in a moderate climate too. In this paper, an existing building is presented that was designed with a passive air conduction system (PACS), where wind and buoyancy effects induce air to be exchanged without external energy needs. The aim is to show that the design methodology, using numerical simulation to give accurate results, is able to use them in further developments. Due to this design process, the specific building possesses numerous special properties, including airflow accelerating elements, solar-heated “chimneys”, and the indoor heat sources coming from the industrial technology. As the building has been constructed and was equipped with around 750 sensors (integrated and manual), it is possible to analyze the ongoing physical phenomenon in a highly detailed way and to collect the experienced dataset for further investigations. The current study carries out a complex validation of the design and the used numerical methods to give general design rules for further PACS design and support following investigations, e.g., occupant comfort prediction or latent heat storage calculation. The experiences showed that the developed computational fluid dynamics technique gives a below 99% accuracy in the velocity and the temperature field, and approximately 85% accuracy in the volume flow values, resulting in a good prediction for aerodynamic characterization of buildings, i.e., passive ventilation air exchange rate.

Buildings are responsible for around 40% of greenhouse emissions globally. The residential building sector is responsible for 24% of energy use. In Hungary, about 800.000 ‘Cube houses’ which date back to the socialist era are still standing. These houses suffer shortages from the energy point of view. This paper presents a new refurbishment approach that attempts to achieve passive cooling with aerodynamic design by integrating the “Venturi disc” which stimulates natural ventilation and night cooling. The work was achieved by using Computational Fluid Dynamics (CFD) simulations using ANSYS Fluent software tool. The implemented building provides lower energy demand and considerably higher comfort in comparison with the typical ‘Cube house’. The building is not only a case study, rather a sustainable model for all the ‘Cube houses’ renewal and further family housing renovations or constructions to reach a higher standard. This paper is a step in an ongoing research project.

Rapid urbanization has resulted in temperature differences between the urban area and its surrounding areas. Academics have called this as the urban heat island phenomenon. Among the places that have seen rapid urbanization is the City of Cebu. The Philippine’s oldest street, Colon, was chosen as the study area due to the near absence of vegetation and closely spaced buildings. Buildings that are spaced more closely as well as multiple absorptions and reflections produce higher and more viable street temperatures. This study tries to systematically understand the urban heat island effect between Colon and Lawaan, the rural area defined in this study. In order to quantify the urban heat island between two given locations, the mobile traverse method during the summer time, for a 10-day period in May 2016. A digital thermometer measuring platform was mounted on top of a vehicle to measure the different temperatures of Colon Street. Urban temperatures were also gathered in the Lawaan area using the same device. Preliminary results showed the presence of the urban heat island phenomenon between the two areas (ΔT =1.17 °C). The provision of green spaces and proper urban planning are essential in mitigating future urban heat stress due to anthropogenic changes of existing cities.

Creating typology is a comparative method to investigate the physical or other characteristics of the built environment. It can be a useful instrument to facilitate the thermal performance assessment of existing buildings. Heat material’s resistance and construction techniques play a significant role in energy performance of buildings. It is influenced by many factors, such as ambient weather conditions, building structure, and heating, ventilation and airconditioning systems. The study was focused on analyzing five types of residential buildings at the center of the Sulaimani city (north of Iraq) to assess the energy performance of the building types and comparing results with dynamic analyses, using IDA ICE 4.7.1 software. The results revealed that the thermal performance of the buildings is mostly influenced by the variations in the construction techniques and materials.

This paper has the main focus in energy consumption by the residential sector in city of Prishtina. Considering the fact that the energy production in Kosovo is not sufficient in relation with the everyday demand and at the same time the growth of the energy demand based on different resources is evident, a detailed analysis and identification of the energy performance of this sector is inevitable. One of the main components that cause the energy demand in residential sector is the heating energy demand. The energy resource and heating systems used by the residential sector in city of Prishtina are diverse. This paper elaborates and identifies the number of residential buildings, number of dwellings, building typologies, heating energy resources, heating systems used by the dwellings and the energy demand for heating energy, by using quantitative methodology. Based on the results achieved by the research, future detailed analysis is possible to identify other components, which affect the heating energy demand by the residential sector. These first results can be used as a basis of the first district scaled energy modeling of the city of Pristhina. By applying the energy management method, developed by Prof. Gerhard Hausladen and his research group at the TU München, a first modeling step will be absolved. After analysis of the current state of the investigated districts, future concepts will be made increasing efficiency and sustainability.

This research aims at demonstrating techniques in complex dynamic building energy simulation methods that greatly reduce the otherwise very time-consuming - in particular cases even week-long - computation time of simulation models, however marginal difference arises in the energy results of the simulations. Different test simulations were created to examine how to simplify the models without altering the energy and comfort results, which lead to reduce also the working hours spent on building the model. The building physics behavior of the zones, heating and cooling equipment in the complex model were studied and tested to understand how those can be used, merged or simplified in order to speed up both computation time and model building phase. The IDA ICE complex dynamic building energy simulation program offers two methods - periodic and dynamic - for calculation, which were compared in this program. Test simulations provide information about possible differences between the results of these calculatio...

Getting the possibility to participate in an actual design process of a Hungarian national sports center is a unique chance to demonstrate and investigate the potential of the dynamic simulation supported building design research program. The research is based on synchronous energy simulations and architectural planning. Energetic and climatic simulations are made during the whole design process. All possible simulated building climate- and energy parameters of the planned versions are compared to each other. In this way it is possible continuously develop the energy and climate characteristic of the designed building. The goal is to reach an accurate design method to be able to predict and minimize the total energy needs of the building as early as the design stage. In the first phase of this process the simulation models of the plan variations are compared, which helps to locate the possible weaknesses of the proposed building geometry and structures or its setting method to develop he building structur...

Accurate building physics performance analysis requires time-consuming, detailed modeling, and calculation time requirement. This paper evaluates the impact of model simplifications on thermal and visual comfort as well as energy performance. In the framework of dynamic zonal thermal simulation, a case study of a residential building in hot climate is investigated. A detailed model is created and simplified through four scenarios, by incrementally reducing the number of thermal zones from modeling every space as a separate zone to modeling the building as a single zone. The differences of total energy and comfort performance in the detailed and simplified models are analyzed to evaluate the grade of the simplifications’ accuracy. The results indicate that all simplification scenarios present a marginal average deviation in total energy demand and thermal comfort by less than 20%. Combining rooms with similar thermal features into a zone presents the optimal scenario, while the worst scenario is the single-zone model. Results showed that thermal zone merging as a simulation simplification method has its limitations as well, whereas a too intensive simplification can lead to undesired error rates. The method is well applicable in further early-stage design and development tasks, specifically in large-scale projects.

The object of the examination is a typical office building of the 1990s, owned by a multinational company -Siemens- dedicated to energy awareness. The building also meets the energy efficiency category ‘A’ under the 7/2006 TNM Hungarian regulations concerning the energy performance definition of buildings. However, demand has emerged to implement additional changes to reduce energy usage whilst keeping the current climate comfort or even improving it. International experience forecasts around 30% energy saving potential due to optimization of the building automation and energy management system, and thus the interaction and collaboration between the building geometry, structures and services systems. The project has been built in the IDA ICE complex building energy simulation program. Running a one-year dynamic simulation will provide data that can be compared with the measured data of the actual building, so the model can be adjusted and validated to real data. After the calibration it is now possible to test the ideas under safe conditions, in a virtual surrounding. Once a particular vision of the model is proven to work effectively, it is possible to apply this to the real building control management as well.

The research is done at the simulation laboratory of the energy design research group of the University of Pécs. Aim of the research is to design a multifunctional shading structure, which is warmed up by solar radiation and then starts an evaporative cooling process. Via this evaporative process the shading structure itself and also the climate facade is cooled down. The experimental climate façade of the Szentágothai Research Center will be used for the purpose of this research. Integrating the shading structure to the climate façade further investigations and simulations will be available.

The energy demand of the built environment is almost 50% of the total energy demand of a national economy. What solutions can architects offer to reduce environmental and energy problems? One of the most effective methods to develop highly efficient, sustainable building systems is a research program based on energy simulations and monitoring of the building management. The research team, the Author involved in, is on the right way to lay down milestones of an accurate design method to be able to predict and minimize the total energy needs of the building as early as the design phase. Pre- and post-processing energetic and climatic simulations are made during the whole design process. Based on the simulation results continuous alteration can be developed on the planned building complex. The main purpose of this paper is to demonstrate the dynamic simulation and measurement concept of the program in an actual demonstration building of the University of Pecs, which is one of Hungary's first energy efficient industrial and office buildings with energy-plus potential.

The Szentagothai Janos Research Center in Pecs brings computer based building physics simulations to reality closer than ever. This high class building ads ground to several medical research programs and lectures, but it also gives a rare opportunity to improve computer simulations with its’ Building Management System (BMS from now on). The system does not only allow the complex building services system to be remotely controlled from a single computer, but also gathers important data related to the buildings’ physical performance, for example: room temperatures; air flow rates; geothermal pipe performance; and energy consumption of heat pumps. By comparing the results of a zone based building physics simulation model of the building, enhancement of the precision of the simulations and optimization of the actual buildings energy consumption can be done, by trying out different maintenance strategies.The first step is to build the computer model to be as precise as possible. In the zone based physical model...

The research topic contributes to the possibilities of energy performance modernization in ‘Squirell Garden’ Nursery School in Csurgo, Hungary. The building bears a special importance for my family and for me, since my mother works there, and I used to attend it as a child. The aim is to achieve an improvement that fulfills the infrastructural requirements set for modern, 21st century nursery schools, that improves the comfort level of children and teachers in the nursery school, makes the maintenance of the facilities more economical and in conformity with regulations, and enhances the quality of education as well as the visual appearance of the building. The target group of the modernization consists of the nursery-school children, parents, nursery-school teachers and nannies, the local government of Csurgo. The study and the calculations implemented are giving a general idea about modernization possibilities of a vintage, since decades unrefurbished kindergarten building, focusing on comfort and low en...

The energy and climate concept of the flagship research institute of the University of Pecs is the result of a three-stage development. The prototypical structures and building services of the first two concepts were developed in line with the financial circumstances and grants and the rationalized third concept became an object for construction research. Through the expansion of the building services and energy supply systems, the building itself has become a ‘measuring apparatus’ for sustainable building construction.

Due to negative environmental changes and the energy supply problems of the society the EPBD 2010/31/EU prescribes for EU member states to ensure that by 2021 all new buildings are nearly zero energy buildings. The Energydesign® research team of the University of Pecs has developed a research-design method applicable for building climate, energy, aerodynamic and architectural technology modeling of smart energy-plus buildings. This problem-solving matrix arranges the systematic structured planning process, calculations, complex analysis, dynamic energy-climate and computational fluid dynamics simulation control of buildings through a finite number of algorithmic steps. The description of the logged design steps is meant to be an instructional process-guide, the Energydesign Roadmap.

The first energy-plus production facility in Hungary, which is developed with Energydesign® planning method and will be realized in 2012, reached its plus energy balance level with help of a special and holistic multidimensional design approach. The novelty of this method lies in dynamic building climate and energy simulations. With simulations supported building modeling complex, precise feedback is obtained already in the early stages of planning about the implications of various design ideas and conceptions in form of indoor climate and energy data. The difference of the performance and the consumption of alternating concepts or the different optimizing development steps of a building can be examined by way of detailed analysis. (1), (2) The optimized model and design plan of the south Hungarian energy-plus industrial and office project was validated with IDA ICE indoor climate and energy dynamic simulations. In this way the simulations ensure quantified effects of modifications due to the construction planning and to the realization of the construction.

Im Planungs- und Entwicklungsprozess des ersten Plusenergie-Produktions- und Innovationszentrums in Ungarn spielten gebaudeaerodynamische Untersuchungen eine essentielle Rolle hinsichtlich der naturlichen Beluftbarkeit, Raumkomfort und Energieeffizienz des Gebaudes. Im Mittelpunkt der Prufung des theoretischen Gebaudemodells standen die zwei stromungstechnisch signifikanten Gebaudebereiche: die Produktionshalle mit passiven Luftungsturmen und das zentrale Atrium. Im Rahmen einer Windkanalstudie wurde untersucht, wie sich das Konzept der naturlichen Luftung unter windinduzierten und thermisch bedingten Antriebskraften verhalt. Hierzu sind die Winddruckverteilungen im Bereich der geplanten Offnungen zu ermitteln und die Turmabdeckvorrichtungen bzw. Dachkonstruktionen aerodynamisch zu optimieren. Die Bewertung der Mess- und Berechnungsergebnisse zeigt, dass das passive Luftungskonzept der im September 2012 fertiggestellten Anlage hinsichtlich Funktion und Effizienz bereits in der Planungsphase nachgewiesen sowie die Baukonstruktionen stromungstechnisch optimiert werden konnten. Wind tunnel measurements for the purpose of quantifying and validation of wind induction and thermal buoyancy effects on natural ventilation in an industrial innovation centre. Building aerodynamic investigations play an essential role in the planning- and development process of the first energy-plus industrial innovation centre in Hungary. The main focus of the analysis concerns with natural ventilation, indoor comfort an energy efficiency in the two significant flow frequented parts of the Building: the production hall with passive ventilation towers and the central atrium. In a wind tunnel study the natural ventilation concept could be surveyed in wind induced and under buoyancy driven conditions. Therefor wind pressure contributions shall be determined and roof constructions must be aerodynamically optimized. The evaluation of the measurements and calculations shows, that the passive ventilation concept of this in September 2012 accomplished construction could be verified already in the planning phase, in regard to function and efficiency, furthermore the structural design was fluid mechanical optimized.

Fur das Konzept der ersten Plusenergie-Produktionsstatte in Ungarn wurde besonderes Augenmerk auf die naturliche Luftung des Gebaudes mit passiven Luftungsturmen gelegt. Mit dem Ziel, die planerischen Ansatze nachvollziehbar prufen zu konnen, wurde ein vierstufiger Algorithmus bestehend aus gebaudeaerodynamischen Untersuchungen in Form von Berechnungen, Windkanaltests, CFD-Simulationen und Messdatenerfassung im Gebaude entwickelt. Durch diese “Validierungsplattform“ konnen nicht nur nachgewiesene Aussagen uber den aerodynamischen Charakter eines Gebaudes getroffen, sondern auch der Einfluss von Anderungen wahrend der Planung und Ausfuhrung sicher quantifiziert und bewertet werden. Daruber hinaus bewirkt die aerodynamische Optimierung eine Verbesserung der Behaglichkeit und Verringerung des Energieverbrauchs. Building aerodynamic investigations for an energy-plus production facility in Sikonda (Hungary). The concept of the first energy-plus production facility in Hungary, which was developed with Energy design method, consists in an essential design approach: the natural ventilation with passive ventilation towers. With the objective of generating comprehensible diagnosis to different design solutions, it was necessary to create a four-level aerodynamic analysis algorithm consisting of calculations, wind tunnel tests, CFD simulations and measurements in buildings. This “validation platform” ensures not only proofed conclusions about the aerodynamic character of a project, but also quantifies in an accurate way the effect of modifications during planning and construction. In addition, the consequence of this aerodynamic optimization of the built environment is the improvement of the indoor comfort and well being as well as the reduction of energy consumption.

In general, people do not connect a concert and conference center with a structure that incorporates ecological energy use and material saving construction methods [1]. A sustainable energy-conscious building has been developed, through a new and unique interpretation of functions and space, organically integrating the individual buildings into the energy concept and by utilizing the laws of the local environmental energy as well as specific laws of physics and acoustics.

U zgradi pozitivne energije u fazi projektiranja vrlo je važno znati koji će dio cjelokupne potrošnje energije biti dobiven iz obnovljivih izvora. U ovom slučaju, u izgradnji tvornice RATI u Komlu, Mađarska, provedene su numeričke simulacije fluida (CFD) kako bi se odredili koeficijenti prijelaza topline (α) za fotonaponske module u toj specifičnoj instalaciji, i provjerila pasivna ventilacija, uz pomoć tako zvanih Venturijevih ploča. Učinkovitost prirodne ventilacije ovisi o geometrijskim svojstvima (otvori, visina Venturi-tornja, konstrukcija Venturi-ploče itd.), a na fotonaponsku učinkovitost također utječe strujanje zraka, jer se njime hlade moduli. Prijelaz topline fotonaponskih modula može se, između ostalih metoda, opisati mrežom otpornosti na toplinu. Ponašanje materijala iznutra ovisi o fizičkim svojstvima, ali se prijelaz topline na rubovima opisuje s α, što uveliko ovisi o protoku zraka oko modula. Ove su CFD simulacije potvrđene stvarnim ispitivanjima aerodinamičkih tunela te se na tim prethodnim ispitivanjima temelji reguliranje ventilacije i mjerenja koja se trebaju obaviti u već postojećoj zgradi., Very important to know at a positive-energy building in the design phase is what portion of the whole energy usage will be collected from renewable resources. In this case, at RATI Factory building in Komlo, Hungary, numerical fluid simulations (CFD) have been made to determine the heat transfer coefficients (α) for photovoltaic modules in this specific installation, and to investigate the passive ventillation, assisted by so-called Venturi-Plates. The efficiency of the natural ventilation depends on the geometrical properties (openings, Venturi-tower height, Venturi-plate design, etc.), and the photovoltaic efficiency is also influenced by air flow, since it is cooling the modules. Heat transfer at photovoltaic modules can be described among other methods, with heat resistance network. The inside of material behaviour depends on physical properties, but the heat transfer at the boundary is described by α, which hangs big rate on the air flow around the modules. These CFD simulations were validated by real wind tunnel tests, and on these pre-tests is based the ventilation control and the coming measurements in the already existing building.