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

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

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

Copper removal from industrial wastewaters by means of electrostatic shielding

Electrostatic shielding zones made of electrode graphite powder were used as a new type of ionic and electronic currentsinks. Because of the local elimination of the applied electric field, voltage and current within the zones, ions are led insidethem and accumulate there. We implemented the current sinks in electrodialysis of a simulated copper plating rinse watercontaining 100 mg L-1 Cu2+ ions and electrodeionization of a 0.001 M CuSO4 solution with simultaneous electrochemicalregeneration of the used ion exchange resin beds and obtained pure water with a Cu2+ ion concentration of less than 0.12 mgL-1 at a flow rate of 1.29x10-4 L s-1 diluate stream and a current density of 2 mA cm-2