Detailed Monitoring Analysis of two Residential NZEBs with a Ground-Water Heat Pump with Desuperheater

Two new, residential, and high performance buildings were constructed according to Passive House standard in Innsbruck, Austria (with cold winters and mild summers). The two multi-family houses consist of 26 apartments - 16 in the north and 10 in the south building. The goal of the project was to achieve net zero energy building (NZEB) standard, which was defined in this project as the annual balance between the electricity consumed for heating and ventilation (excluding household appliances), and the electricity produced by renewable sources. Thus, a heat pump, solar thermal collectors, photovoltaics (PV) and ventilation units were installed. The two stage ground water source heat pump with a power of 58 kW (at W10/W35) includes desuperheater. The available roof space of the north building was covered by a solar thermal system with 74 m2 and PV with 52.5 m2 (8.5 kWp). An additional PV system of 99.8 m2 (16 kWp) was placed in the roof of the south building. The ventilation units were centralized (three in total) including heat recovery. In combination with floor heating and a heat exchanger in each flat for domestic hot water (DHW), a four pipe distribution system was used to minimize the distribution losses; two pipes for the DHW (flow temperature of 52°C) and two pipes for the space heating (with flow temperature of 35°C). Therefore, stratification was obtained in the 6000 liter storage to improve energy performance, since the heat pump can operate at a low sink temperature for supplying space heating. A detailed monitoring system was installed consisting of 58 temperature sensors, 12 humidity sensors, 2 pressure sensors, 37 signals (e.g. controllers, valves, pumps, etc.), 22 heat meters, 7 electricity meters, and 2 volume flow meters. The main focus was the energy performance of the HVAC systems. The thermal comfort of the south building was monitored, too. The operation of a monitoring system has started in November 2015. In this paper, results of monitoring of three heating seasons are highlighted and discussed. The energy performance of the technical system and each subsystem is presented in detail. The performance of the heat pump with respect to the two compressors and the desuperheater is in the focus. Supplementary to the monitoring data, simulations were performed aiming to optimize the system, and support the monitoring results. In addition, the importance of quality assurance control e.g. with monitoring is highlighted. The present study enhances the discussion about evaluation of NZEBs with a monitoring example from central Europe, and contributes to improve the knowledge with respect to the use of desuperheater in a heat pump via a comprehensive analysis

Evaluation of Efficiency and Renewable Energy Measures Considering the Future Energy Mix

Sustainable and responsible use of resources is required in order to mitigate climate change. Micro-economic goals usually consider the capitalized investment costs and/or the purchased energy but disregard environmental impacts. However, on macro-economic scale, the aim must be the reduction of the (non-renewable) primary energy (PE) use and of CO2-emissions. There is need for an appropriate evaluation method for comparing and ranking different passive and active building technologies, e.g. according to their impact on the PE consumption. National conversion factors for PE/CO2 differ significantly between different countries and are subject to change. Seasonal variations are not considered at all. The electricity mix is and will be influenced to a higher extend in future by the available renewable energy sources, which are hydropower, wind energy and PV with strong differences in daily and seasonal availability. Without presence of seasonal storage, fossil fuels will predominantly cover the winter load. The electricity mix is also influenced by the load: buildings, have a high demand in winter, and lower in summer. The share of electricity for heating is still relatively low, but will increase with the more widely use of heat pumps and electric heating. Hence, savings in winter will have higher value. This paper discusses - using a realized NZE multi-family building as an example - a PE evaluation method, that allows to include future development of the load (i.e. building stock) and electricity mix (share of REs) with seasonal variations and shows the impact on the ranking of different passive and active technologies

Prefabricated Timber Frame Façade with Integrated Active Components for Minimal Invasive Renovations

AbstractThe objective of the EU-funded project iNSPiRe is to tackle the problem of high-energy consumption by producing systemic renovation packages that can be applied to residential and tertiary buildings. The renovation packages aim to reduce the primary energy consumption of a building to lower than 50 kWh/(m2 a) for ventilation, heating/cooling, domestic hot water and lighting. The packages need to be suitable for a various climates in Europe while ensuring optimum comfort for the building users. One major aspect of iNSPiRe is the development of multifunctional renovation kits that make use of innovative envelope technologies, energy generation (including RES integration) and energy distribution systems. The technologies and renovation approaches developed by the iNSPiRe project will be installed and tested in three demo buildings. In this work the development, testing and modelling of a timber frame façade with integrated mechanical ventilation with heat recovery (MVHR) and a micro- heat pump (μ-HP) is presented. Three functional models were built for testing in so-called PASSYS test cells for the assessment of the thermal performance and for testing in the acoustic test rig at UIBK. Experimental results are used to validate a physical heat pump and MVHR model. The μ-HP with MVHR is a cost-effective and compact solution for ventilation and heating/cooling for buildings with high standard such as PH or EnerPHit. The integration of active components such as the MVHR and μ-HP in a prefabricated façade enables minimized space use and reducing installation time and effort

Enhanced Performance Buildings Connected to District Heating Systems: Multi-Objective Optimisation Analysis

The European directive 2010/31/EU states that within the end of 2020, all new buildings should be nearly zero-energy buildings (NZEB), and in the meanwhile, new and renovated buildings performance should comply with new requisites established through a cost-optimal approach. For new buildings, Member States shall ensure that, before construction starts, the technical, environmental and economic feasibility of high-efficiency alternative systems are considered and taken into account, such as, among others, decentralised energy supply systems based on energy from renewable sources, cogeneration, district or block heating or cooling. However, the reduction of the heat needs of the buildings causes a partial utilization of the district heating (DH) capacity with a consequent possible reduction of the distribution efficiency. How to combine the reduction of energy needs and their duration with the technical and economical sustainability of DH and cogeneration systems is an open question. This paper aims to define the cost-optimal solutions of refurbishment for buildings connected to a DH considering the impact on both the heat demand reduction and network distribution losses. The possibility to shift to a low-temperature DH is considered a feasible solution to reduce thermal losses and hence increasing the network efficiency that is connected with a systematic approach to the refurbishment of the connected buildings. For this purpose, an integrated model has been developed and calibrated on real data of a DH system based on biomass and located in northern Italy. The energy performance of the coupled DH - buildings system has been assessed taking into account different measures for the improvement of the existing buildings and different numbers of refurbished buildings. The improvements involve building envelope, heating system and strategies of heating management. A multi-objective optimization has been carried out considering the minimization of the energy needs, the minimization of the net present value (NPV) for the final user and the maximization of the distribution efficiency of the DH, in terms of distribution temperature. The optimization has been also carried out considering different prices policies for heat sales according to its temperature level to assess how it can promote the efficiency of the DH. The results highlight the optimal measures that allow the minimum NPV of the building refurbishment and the highest efficiency of the considered DH system

Detailed cross comparison of building energy simulation tools results using a reference office building as a case study

Building Energy Simulation (BES) tools play a key role in the optimization of the building system during the different phases, from pre-design through commissioning to operation. BES tools are increasingly used in research as well as in companies. New BES tools and updated versions are continuously being released. Each tool follows an independent validation process but rarely all the tools are compared against each other using a common case study. In this work, the modelling approaches of widespread dynamic simulation tools (i.e. EnergyPlus, TRNSYS, Simulink libraries CarnotUIBK and ALMABuild, IDA ICE, Modelica/Dymola and DALEC), as well as PHPP (a well-known quasi-steady-state tool), are described and the results of all the tools modelling the same characteristic office cell, defined within the IEA SHC Task 56, are compared on a monthly and hourly basis for the climates of Stockholm, Stuttgart and Rome. Unfortunately, different tools require different levels of input detail, which are often not matching with available data, hence the parametrization process highly influences the quality of the simulation results. In the current study to evaluate the deviation between the tools, frequently used statistical indices and normalization methods are analysed and the problems related to their application, in a cross-comparison of different tools, are investigated. In this regard, the deviation thresholds indicated by ASHRAE Guideline 14-2014 are used as a basis to identify results that suggest an acceptable level of disagreement between the predictions of a particular model and the outcomes of all models. The process of reaching a good agreement between all tools required several iterations and great effort on behalf of the modellers. To aid the definition of building component descriptions and future references for inter-model comparison a short history of the executed steps is presented in this work. Together with the comparison of the results of the tools, their computational cost is evaluated and an overview of the modelling approaches supported by the different tools for this case study is provided aiming to support the users in choosing a fit-for-purpose simulation tool

Hourly simulation results of building energy simulation tools using a reference office building as a case study

The data presented in this article are the results of widespread building simulation tools (i.e. EnergyPlus, TRNSYS, Simulink/CarnotUIBK, Simulink/ALMABuild, IDA ICE, Modelica/Dymola and DALEC) used to simulate a characteristic office cell, described within IEA SHC Task 56 [1], located in Stockholm, Stuttgart and Rome. Hourly data for each component of the thermal balance (i.e. Heating, cooling, infiltration, ventilation, internal gains, solar gains) and the hourly convective and radiative temperatures are reported for all the tools along with the ambient temperature and solar irradiation on the south façade. The mainly used statistical indices (i.e. Mean Bias Error, Mean Absolute Error, Root Mean Square Error and coefficient of determination) are applied to evaluate the accuracy of the tools. For more insight and interpretation of the results, please see “Detailed Cross Comparison of Building Energy Simulation Tools Results using a reference office building as a case study” [2]. This data set and evaluation methods are made available to ease the cross-validation process for other researchers

Visualization and quantitative analysis of nanoparticles in the respiratory tract by transmission electron microscopy

Nanotechnology in its widest sense seeks to exploit the special biophysical and chemical properties of materials at the nanoscale. While the potential technological, diagnostic or therapeutic applications are promising there is a growing body of evidence that the special technological features of nanoparticulate material are associated with biological effects formerly not attributed to the same materials at a larger particle scale. Therefore, studies that address the potential hazards of nanoparticles on biological systems including human health are required. Due to its large surface area the lung is one of the major sites of interaction with inhaled nanoparticles. One of the great challenges of studying particle-lung interactions is the microscopic visualization of nanoparticles within tissues or single cells both in vivo and in vitro. Once a certain type of nanoparticle can be identified unambiguously using microscopic methods it is desirable to quantify the particle distribution within a cell, an organ or the whole organism. Transmission electron microscopy provides an ideal tool to perform qualitative and quantitative analyses of particle-related structural changes of the respiratory tract, to reveal the localization of nanoparticles within tissues and cells and to investigate the 3D nature of nanoparticle-lung interactions

Nachhaltigkeit im industriellen Umfeld

Im Rahmen der Lehrveranstaltung "Nachhaltigkeit im industriellen Umfeld" im Masterstudiengang Umwelt- und Verfahrenstechnik der Hochschulen Konstanz und Ravensburg-Weingarten wurde 2015 eine studentische Fachkonferenz durchgeführt. Die Studierenden entwickelten in Einzelarbeit oder als Zweierteam Konferenzbeiträge zu folgenden Themen: - Innovationen und Spannendes aus dem Bereich der Energieerzeugung und -wandlung - Aspekte der Schließung von Stoffkreisläufen und Vermeidung von Schadstoffeinträgen in die Umwelt - Chancen und Herausforderungen Nachwachsender Rohstoffe bei verschiedenen Einsatzmöglichkeiten sowie Themen der Nachhaltigkeit in der Landwirtschaft - verschiedene Blickwinkel auf das Thema Wasser (von der Abwasserreinigung bis zum Wasserkonsum der Konsumenten) - die Betrachtung spezifischer Industrien und Unternehmen sowie deren Werkzeuge zur Umsetzung von Nachhaltigkeit Die Ergebnisse der studentischen Fachkonferenz zur „Nachhaltigkeit im industriellen Umfeld“ werden in der vorliegenden Publikation präsentiert