Monitoring and modeling of the urban micro-climate

Urban heat island phenomenon (UHI) is considered to be one of the major challenges encountered this century by the human kind. This phenomenon is characterized mainly by air temperatures in the city that are higher than those in the surrounding areas. Reasons are, amongst other things, the morphology and density of urban spaces as well as the thermal and radiative properties of outdoor surfaces. The UHI effect represents a challenge for careful and proper building design and operation, as micro-climatic data are typically available only for few locations in the city. As a result, planning, retrofit, and mitigation measures for buildings cannot count on reliable weather information for the exact locations of intended building projects. In this context, this paper presents results of an ongoing research project, which is concerned with prevention, adaptation, and mitigation measures pertaining to the urban heat island phenomenon. An important component of this project addresses the variation in the mirco-climatic conditions in different locations in the city and if and how such variations could be accounted for. Specifically, weather information was collected with a mobile weather station at various locations within the city of Vienna. Collected data from multiple - morphologically differentiated - locations around the city were compared with the simultaneously monitored general weather conditions via a stationary weather station. The findings are expected to support the development and validation of high-resolution climatic boundary condition models for building design and operation support

Short-term occupancy implications of digitally provided outside views in window-less rooms

This paper investigates the perception and performance of occupants in rooms with and without visual connection to outside. Thereby, experiments were conducted with two groups of participants in a laboratory containing two test cells. One of the cells is equipped with a flat panel display, which acts as a virtual window. The other cell has no such display. Participants in the experimental group were exposed, via the virtual window, to different scenes. The control group in the window-less room was not exposed to such treatment. During the experiments, participants were asked to fill in a questionnaire regarding indoor environment. Additionally, they were asked to perform a number of typical problem-solving tasks. The discussion of the experimental results addresses the question, if and to which extent the existence of a virtual connection to the outside world in window-less spaces can improve occupants' perception and performance

Multi-stage optimal design of energy systems for urban districts

Urban districts develop in a dynamic manner over multi-year horizons with new buildings being added and changes being made to existing buildings (e.g. retrofits). Nevertheless, optimization models used to design urban district energy systems (DES) commonly consider a single, “typical” year for the design. This practice, however, does not allow for energy design decisions to be made in multiple phases in order to reflect a district’s development phases. This paper addresses this issue and presents a novel optimization model that allows the multi-stage optimal design of urban DES. The model identifies the cost-optimal technology investment decisions across a horizon that spans multiple years, while also calculating the energy system’s optimal operating patterns in order to meet the district’s energy demands. The evolution of the district’s energy demands and aspects like the evolution of technology costs and energy carrier prices are considered in the model. The model is applied to a new urban district in Zurich, Switzerland, for which 5 development stages are considered with new buildings of various types constructed in each phase. A multi-stage DES design plan is developed for the period 2021-2050, which includes large energy technology investments for each new development phase, but also smaller ones in the intermediate years between 2021 and 2050. The model specifies the amount of energy generated by each technology installed in each year, as well as the contribution of renewable energy in covering the district’s energy demands

Assessment of Renewable Energy Integration for a Village Using the Energy Hub Concept

AbstractThe built environment represents a major share of global energy consumption. To effectively reduce the energy consumption of urban conglomerations, concepts to sufficiently integrate and manage energy from renewables are necessary. In this paper the energy-hub concept will be applied, which describes the relation between input and output energy flows and can be used to optimize the energy consumption during planning and operation. The concept will be used to evaluate a number of future energy scenarios for a village in Switzerland which has the goal of eliminating the consumption of fossil fuels. As a starting point the existing situation concerning the energy demand of the village with respect to different uses, the different energy carriers, their origin, their distribution and networks is captured and analyzed. In the next step the potential for different means of decentralized energy production is evaluated. Decentralized energy production includes building integrated or local renewable energy production by photovoltaics, biomass, or small hydro power. In the third step, different future energy scenarios for an energy sustainable community are defined. These different scenarios are distinguished by their scale of implementation. Finally an energy hub model of the village is developed and used to evaluate the different energy scenarios

Urban heat island phenomenon in Central Europe

The urban heat island (UHI) phenomenon is characterized by significantly higher temperatures in metropolitan areas as compared to the surrounding suburban and rural neighborhoods. In this context, this paper presents a preliminary report pertaining to an ongoing EU-supported research project, which investigates the urban heat island phenomena in Central Europe. First, the background and general scope of the UHI phenomena are discussed. Subsequently, the paper investigates the manifestation of the urban heat islands phenomena (especially in the city of Vienna) and evaluates possible mitigation and adaptation strategies

Energetski učinkovita proizvodnja – interdisciplinarni, sistemski pristup kroz integralnu simulaciju

If the main concern of manufacturing companies was increasing the productivity, reliability, flexibility, and quality of the industrial process, more recently the energy efficiency of the production process and facilities has come under scrutiny. To enhance the energy-efficiency of production facilities, detailed information regarding the production processes, heat emissions from machines, operation level and occupancy analysis are necessary. In this context, the present paper describes an ongoing research effort that aims to develop a systemically integrated model of an energy efficient production facility. In this context we demonstrate the initial results of the implementation of an integrated simulation approach for a specific industrial facility. On the case study of an existing facility the different levels of energy in-and outputs were analysed; starting from machines and production systems, user behaviour and building services related requirements, to the building envelope of the facility. The collected information was further processed to develop a new building design. This layout provides the basis of an initial building performance simulation model. The generated model is part of the integrated simulation approach and used as a starting point to address the impact of different design and building operation options on the indoor climate and energy performance of the industrial facility. The goal of the integrated simulation approach is to evaluate a production facility not separately for individual mandates pertaining to production process, building envelope, and systems, but in a coupled and integrated fashion. Based on the results of thermal simulation, a first life-cycle costs model is developed, upon which the crucial points for the decision-making process in the planning of an energy-efficient industrial facility can be identified.Među glavnim interesima proizvodnih poduzeća do sada su bili povećanje produktivnosti, pouzdanosti, fleksibilnosti i kvalitete industrijskog procesa, a nedavno se pod povećalom našla i energetska učinkovitost proizvodnog procesa i pogona. U cilju poboljšanja energetske učinkovitosti proizvodnih pogona potrebne su detaljnije informacije o procesu proizvodnje, izmjeni topline u strojevima i analiza učinka i zastupljenosti pogona u radu. U tom kontekstu, ovaj rad opisuje istraživanje koje je u tijeku i teži razvoju sustavno integriranog modela energetski učinkovite proizvodnje u pogonu. U tom kontekstu prikazani su početni rezultati provedbe integriranog simulacijskog pristupa za određeni industrijski pogon. U početnoj studiji slučaja postojećeg pogona analizirane su različite razine ulaznih i izlaznih podataka o energiji; uključujući strojeve i proizvodne sustave, ponašanja korisnika, učinkovitosti kućne tehnike te ovojnice zgrade pogona. Prikupljeni podaci dodatno su obrađeni u cilju razvoja novog građevinskog projekta. Prijedlog koncepcije novog pogona pruža osnovu za prikaz početnog učinka simulacijskog modela na zgradi. Razvijeni model je dio integriranog simulacijskog pristupa te se koristi kao početna točka u simulaciji utjecaja različitih koncepata organizacije prostora i volumena zgrade, kvalitete ovojnice zgrade i kućne tehnike na energetsku učinkovitost industrijskog pogona. Cilj integriranog simulacijskog pristupa je procijeniti energetske performanse proizvodnog pogona, ali ne za pojedine zadaće koje se odnose na proces proizvodnje, ovojnicu zgrade i sustave, nego na povezani i integrirani način. Razvijen je prvi modela troška vijeka trajanja koji se temelji na toplinskim simulacijama, koji je presudan u procesu donošenja odluka u planiranju energetske učinkovitosti industrijskog pogona