41 research outputs found
RoofKIT â Building simulation in sustainable housing at the Solar Decathlon Europe 21/22
The contribution of the RoofKIT student team to the SDE 21/22 competition is the extension of an existing café in Wuppertal, Germany, to create new functions and living space for the building with simultaneous energetic upgrading. A demonstration unit is built representing a small cut-out of this extension. The developed energy concept was thoroughly simulated by the student team in seminars using Modelica. The system uses mainly solar energy via PVT collectors as the heat source for a brine-water heat pump (space heating and hot water). Energy storage (thermal and electrical) is installed to decouple generation and consumption. Simulation results confirm that carbon neutrality is achieved for the building operation, consuming and generating around 60 kWh/m2a
Evidence-based numerical building model enhancement and building energy efficiency evaluation in the case of Morocco
This paper presents a framework for numerical building validation enhancement based on detailed building specifications from in-situ measurements and evidence-based validation assessment undertaken on a detached sustainable lightweight building in a semi-arid climate. The validation process has been undergone in a set of controlled experiments â a free-float period, and steady-state internal temperatures. The validation was conducted for a complete year with a 1-min time step for the hourly indoor temperature and the variable refrigerant flow (VRF) energy consumption. The initial baseline model was improved by three series of validation steps per three different field measurements including thermal transmittance, glazing thermal and optical properties, and airtightness. Then, the accurate and validated model was used for building energy efficiency assessment in 12 regions of Morocco. This study aims to assess the effect of accurate building characteristics values on the numerical model enhancement. The initial CV(RMSE) and NMBE have improved respectively from 14.58 % and â11.23 %â7.85 % and 1.86 % for the indoor temperature. Besides, from 31.17 % to 14.37 %â20.57 % and 9.77 % for energy consumption. The findings demonstrate that the lightweight construction with the use of a variable refrigerant flow system could be energy efficient in the southern regions of Morocco
Development of a new urban climate model based on the model PALMÂ â Project overview, planned work, and first achievements
In this article we outline the model development planned within the joint project Model-based city planning
and application in climate change (MOSAIK). The MOSAIK project is funded by the German Federal
Ministry of Education and Research (BMBF) within the framework Urban Climate Under Change ([UC]2)
since 2016. The aim of MOSAIK is to develop a highly-efficient, modern, and high-resolution urban climate
model that allows to be applied for building-resolving simulations of large cities such as Berlin (Germany).
The new urban climate model will be based on the well-established large-eddy simulation code PALM, which
already has numerous features related to this goal, such as an option for prescribing Cartesian obstacles. In
this article we will outline those components that will be added or modified in the framework of MOSAIK.
Moreover, we will discuss the everlasting issue of acquisition of suitable geographical information as input
data and the underlying requirements from the modelâs perspective
Overview of the PALM model system 6.0
In this paper, we describe the PALM model system 6.0. PALM (formerly an abbreviation for Parallelized Large-eddy Simulation Model and now an independent name) is a Fortran-based code and has been applied for studying a variety of atmospheric and oceanic boundary layers for about 20 years. The model is optimized for use on massively parallel computer architectures. This is a follow-up paper to the PALM 4.0 model description in Maronga et al. (2015). During the last years, PALM has been significantly improved and now offers a variety of new components. In particular, much effort was made to enhance the model with components needed for applications in urban environments, like fully interactive land surface and radiation schemes, chemistry, and an indoor model. This paper serves as an overview paper of the PALM 6.0 model system and we describe its current model core. The individual components for urban applications, case studies, validation runs, and issues with suitable input data are presented and discussed in a series of companion papers in this special issue.Peer reviewe
Messtechnische Evaluation von thermisch und elektrisch angetriebener KĂ€lteerzeugung
Thermisch angetriebene (Adsorptions-)KĂ€ltemaschinen können mit einem verhĂ€ltnismĂ€Ăig geringen elektrischen Energieaufwand bzw. mit einer hohen elektrischen Leistungszahl KĂ€lte bereitstel-len. Wird die zum Antrieb erforderliche WĂ€rme aus industrieller AbwĂ€rme bereitgestellt, ist diese KĂ€ltebereitstellung energetisch effizienter als die KĂ€ltebereitstellung ĂŒber eine KompressionskĂ€l-temaschine. Wird die WĂ€rme jedoch in Kraft-WĂ€rme-Kopplung bereitgestellt, ist die primĂ€renergetische Bewertung sowohl von mehreren Teilwirkungsgraden als auch den PrimĂ€renergiefaktoren fĂŒr den eingesetzten Brennstoff und die erzeugte bzw. bezogene elektrische Energie abhĂ€ngig. Eine umfangreiche Messkampagne im Sommer 2018 liefert unter realitĂ€tsnahen Randbedingungen in einer Labor umgebung detaillierte Energiekennzahlen fĂŒr einen typischen Tagesgang des KĂ€ltebedarfs. Damit gelingt es, Teilenergiekennwerte fĂŒr die Planungspraxis abzuleiten und das Gesamtsystem energetisch mit einer konventionellen KompressionskĂ€ltemaschine zu vergleichen.Thermally driven (adsorption) chillers can provide cold energy with a relatively small amount of electrical energy or with a high elec-trical coefficient of performance, respectively. If the heat required as driving energy is provided by industrial waste heat, this kind of cold generation is more energy-efficient than the supply of cold via a compression cooling machine. If the heat is provided in combined heat and power, the primary energy rating will depend on both the number(s) of partial efficiencies and the primary energy factors for the fuel used as driving energy and the electrical energy which is fed in the public grid. An extensive measurement campaign in the summer of 2018 delivered detailed energy figures for a typical daily cycle of cooling demand under realistic boundary conditions in a laboratory environment. Based on the evaluation of the overall energy balance, we derive parameters for planning practice and compare the tri-generation system with a conventional compression cooling system
Energy efficient cooling and thermal interior comfort: comparison of eight European nonâresidential buildings
Unter dem europĂ€ischen Programm Intelligent Energy for Europe (IEE) fanden sich acht europĂ€ische Partner zusammen, um im Rahmen des Projektes ThermCo LĂŒftungsâ und KĂŒhlenergiekonzepte fĂŒr NichtwohngebĂ€ude mit niedrigem Energieeinsatz im Hinblick auf die Energieeffizienz und den thermischen Raumkomfort zu bewerten. Die Analyse erfolgte auf Basis von detaillierten Langzeitmessungen ĂŒber ein Betriebsjahr in acht DemonstrationsgebĂ€uden in unterschiedlichen klimatischen Zonen Europas und einer standardisierten Datenauswertung. Im Quervergleich aller acht GebĂ€ude werden die KĂŒhlkonzepte gleichermaĂen nach dem thermischen KĂŒhlenergiebezug, dem thermischen Raumkomfort und dem PrimĂ€renergieeinsatz fĂŒr die technische GebĂ€udeausrĂŒstung und die Beleuchtung bewertet. Ein Energiekonzept ist erst dann zufriedenstellend, wenn mit möglichst geringem Energieeinsatz und bei hoher Anlageneffizienz ein guter thermischer Raumkomfort zur VerfĂŒgung gestellt werden kann. Mit entsprechenden GebĂ€udesignaturen werden diese Parameter in einen Zusammenhang gebracht und die Zielstellung ĂŒberprĂŒft. Detaillierte Komfortuntersuchungen nach der europĂ€ischen Komfortnorm DIN EN 15251:2007â08 geben Hinweise auf die Wirksamkeit der eingesetzten KĂŒhltechnologien in den jeweiligen Klimazonen. Daraus lassen sich Handlungsempfehlungen ableiten.Under the framework of the European Program Intelligent Energy for Europe (IEE), the project ThermCo evaluates lowâenergy ventilation and cooling concepts for nonâresidential buildings allâover Europe using a standardized method based on existing monitoring data from best practice examples. The proposed approach is applied to eight demonstration projects in different climatic zones of Europe. The analysis is based on longâterm monitoring campaigns in highâtime resolution over one year of operation. In crossâcomparison of all eight buildings, the cooling concepts are evaluated according to the thermal cooling energy consumption, the thermal interior comfort, and the buildingâs total primary energy use for heating, cooling, ventilation, and lighting
Hitzestress im AuĂen- und Innenraum der Stadt â Verwundbarkeitsanalyse fĂŒr Reutlingen
Low-Energy Buildings with Night Ventilation and Air-to-Air Heat Exchangers - Case Studies and Analysis
This study presents some results from a monitoring project with night ventilation and earthto-air heat exchanger. Both techniques refer to air-based low-energy cooling. As these technologies are limited to specific boundary conditions (e.g. moderate summer climate, low temperatures during night, or low ground temperatures, respectively), water-based low-energy cooling may be preferred in many projects. A comparison of the night-ventilated building with a ground-cooled building shows major differences in both concepts
Betriebserfahrungen mit thermoaktiven Bauteilsystemen
Buildings that are cooled and, if applicable, heated by thermo-active building systems (TABS) in combination with environmental energy have been established in the market during the last years. Many successful and efficient examples prove, that these systems can achieve a good thermal room comfort with a high energy efficiency of the plant system using environmental energy (mainly surface-near geothermal energy). However, operating experience and a systematic evaluation of several building projects demonstrate that there is potential improvement in the design, implementation, and operation of TABS systems. The article presents operating experience and a detailed evaluation of the operation performance of several non-residential buildings with thermo-active building systems with respect to thermal comfort and energy efficiency