Conference Agenda

Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).

Session Overview
Session 23: ZEB (zero energy buildings)
Thursday, 26/Aug/2021:
2:00pm - 3:30pm

Session Chair: Prof. Arild Gustavsen, NTNU
Location: Room 3 - Room 013, Building: 116

Show help for 'Increase or decrease the abstract text size'
2:00pm - 2:15pm

Energy and environmental evaluation of retrofitting façades for Zero Energy Buildings in the Mediterranean region

Effrosyni Giama, Elli Kyriaki, Panagiota Antoniadou, Maria Symeonidou, Agis Papadopoulos

Aristoteles University of Thessaloniki, Greece

Energy and environmental targets are expressed clearly by the EU policies setting ambitious goals for 2030 and 2050 considering energy intensive sectors such as buildings. Pursuing high energy performance with the least environmental impact of a building, along with ensuring the well-being of the occupants, is the ultimate goal of an institutional framework that addresses energy efficiency and environmental sustainability. Part of this effort is the improvement of the building envelope’s thermal performance, along with the respective one of HVAC systems, as those determine thee energy performance of buildings in their use phase. Main scope of the paper is to evaluate and analyse different scenarios considering the retrofitting of facades as part of the refurbishment towards Zero and Positive Energy Buildings, but also in connection with the strive for Net Zero Energy, Net Zero Cost Energy and Net Zero Emissions goals. The paper also discusses energy and environmental evaluation of refurbishing an office building in Greece, examining the performance of different envelope construction typologies and alternative insulation scenarios.

These scenarios include state of the art insulation techniques, but also innovative design elements such as the use of different final coating materials for ventilated façades, the use of phase-changing materials (PCMs) and the integration of high efficiency photovoltaic elements, that utilized diffuse radiation to a greater extent.

The results of the assessment undertaken are used to rate the construction solutions by means of energy and environmental parameters. Considering the environmental evaluation, the carbon footprint analysis was used according to Greenhouse Gas Protocol focusing mainly on CO2 emissions, which is the main emission target of EU policies.

2:15pm - 2:30pm

The ZEB Laboratory: a research tool for future climate adapted zero emission buildings

Alessandro Nocente1, Berit Time1, Hans Martin Mathisen2, Tore Kvande2, Arild Gustavsen2

1Sintef AS, Trondheim, Norway; 2NTNU, Trondheim, Norway

The building sector is responsible for approximately 40 % of the energy consumption and carbon emissions worldwide. Future buildings will have to comply not only with stricter energy regulations, but they will also face changing climate conditions. To increase the level of knowledge and to develop and test innovative technological solutions with users, new types of adaptive research facilities is needed. The ZEB Laboratory was realised by NTNU and SINTEF in Trondheim, Norway in 2020. The edifice is a living laboratory, able to accommodate both test environments and office space where users also become parameters, giving load variations, and a sensor providing the researcher with feedback. New components, materials, solutions, and control strategies can be tested in the laboratory, reducing the associated risk for involved stakeholders thus helping the diffusion of enhanced technologies in the building industry.
The whole building is realised following the Norwegian ZEB-COM ambition which means that the amount of renewable energy produced locally during the whole life of the facility (assumed 60 years) will balance the carbon emission related to the materials, the construction process and operation.
This calls for an iterative approach with use of partnering and collaborative elements for planning and production of the ZEB Laboratory, where interconnected challenges related to e.g. indoor environment, energy and building physics has to be solved through the iterations and co-creation processes.
This paper presents and assess the development and the building process of the ZEB Laboratory as a research tool for climate adaptation and climate mitigation measures for buildings included stormwater management at site, and conclude with advices for future building processes of the future. The main characteristics, systems and research potential are also described.

2:30pm - 2:45pm

Role of onsite thermal and electric storage in nZEBs

Fabian Ochs, Mara Magni, Elisa Venturi, Alice Tosatto

University of Innsbruck, Austria

At the end of 2020, all new buildings in the European Union must be nearly zero-energy buildings (nZEBs) in order to contribute to the achievement of the EU-CO2 neutrality by 2050. As the technical options to achieve highly-efficient building envelopes are available and well-known, there is no doubt that the most promising HVAC systems will include heat pumps (HPs) and photovoltaic (PV) panels. However, there exist ongoing discussions on the optimal system layout and the integration of storage to achieve nZEB. In particular, there are some good arguments in favour of very low demand, while contrariwise also high flexibility is seen as an important feature to enable so-called grid-reactive operation of the building stock.

A method to compare the so-called ambition level (i.e. the comparison of the deviation in terms of lifecycle costs and primary energy requirements for the cost-optimal option) considering different climatic and boundary conditions is presented. For this purpose, an exemplary case study of an individual single-family-house with air-water heat pump and storage is studied using simulation tools. Various heat pump concepts for the realization of nZEBs were investigated. Herein, the investigation included the heat pump integration together with locally available renewable energy sources for application in nZEBs.

For the investigated virtual cases the potential of integrating passive and active solar technology and the role of onsite storage is shown. A methodology was developed to analyse and compare different solutions. Furthermore, the results can be used to further foster and optimize nZEB design and implementation and the role of storage. Special focus will be given on its influence on the energy demand and the peak power of the building stock. The investigation allows to conclude on the role of on site storage and the required central storage capacity as a basis for the developement of design guidelines.

2:45pm - 3:00pm

The Costs and Benefits of an Irish Low-Energy Social Housing Deep Energy Retrofit case study

Shane Colclough

Ulster University, United Kingdom

This analysis provides technical details and the associated of a recent 12-unit Deep Energy Retrofit (DER) social housing project. It then quantifies the multiple benefits – e.g. financial, economic and societal benefits and presents a project stakeholder analysis. The analysis is apposite given the urgent need for effective policy development in order to re-orient society and industry and enable the achievement of the low-energy retrofit mandated by the EU.
The Multiple Beneficiary Analysis (MBA) covers the technical specifications, the actual costs of upgrading the dwellings to the low-energy standards, the direct and indirect financial and economic benefits which accrue over a 15-year period, and the financial perspectives of the involved stakeholders. The direct benefits include reduced energy consumption, reduced CO2 emissions, reduced maintenance costs and increased capital and rental value, while the indirect benefits include improved health and economic benefits. The stakeholders (beneficiaries) identified are landlord, tenant and Central Exchequer and a clear picture of their respective financial gains (or losses) emerges.
A key finding from the analysis is that the stakeholder who benefits most (the tenant) makes no financial contribution to the higher standards, the Central Exchequer benefits significantly, yet the stakeholder who makes the upgrade decision (landlord) benefits least.
Given the significant benefits which accrue to the Central Exchequer, there is an opportunity for strategic investment by the government to unlock the benefits of low energy dwellings. This would simultaneously realise ongoing financial benefits, “seed” the capability within industry and crucially increase the knowledge and understanding of low energy dwellings which is necessary to enable the appropriate market valuations so widespread adoption can be achieved.
The key finding is that despite the returns of circa twice the investment, and the urgent need to retrofit existing building stock, the required DER uptake is unlikely as the decision-makers are financially dis-incentivised.

3:00pm - 3:15pm

Experimental and numerical assessment for HVAC management in an industrial building: a preliminary optimization

Ettore Stamponi1, Nicola Lattanzi1, Elisa Moretti2

1CIRIAF - Interuniversity Research Centre, University of Perugia, Via G. Duranti 63 (Perugia, Italia); 2Department of Engineering – University of Perugia, Via G. Duranti 93 (Perugia, Italia)

COVID-19 emergency has caused major changes in everyday life in the last months, and it also affected the management of buildings. In particular, indoor air quality and ventilation have been considered to play a key role in the spreading of the infection, causing national and international subjects to draw up specific guidelines on ventilation and air recirculation rate in AHUs. The paper deals with the “Loccioni Leaf Lab”, an industrial building connected to a thermal and electric smart grid that offers the possibility of maximizing the benefits that can be obtained by optimal regulation of the grid itself, providing excellent economic and energetic results. The case study, which hosts offices and workers operating on test benches, features high performance envelope, solar photovoltaic systems, groundwater heat pumps and a hightechnology control and monitoring system, which includes indoor temperatures and air quality parameters. Then, a validated model of the building, realized with the software DesignBuilder and EnergyPlus, was used to carry out numerical simulations in order to optimize the management of the HVAC through the Building Management System. Different working conditions have been simulated, and the numerical output has been used together with experimental data collected from the Company monitoring system. It has been possible to investigate how the extra ventilation required by the new guidelines would affect the total energy consumption and to compare, in terms of energy efficiency, the different HVAC management strategies that could be used to ensure occupants health safety and indoor air quality.

3:15pm - 3:30pm

''Analysing energy upgrading projects of single-family houses towards a Norwegian nZEB level


1SINTEF Community, Postboks 4760 Torgarden, 7465 Trondheim, Norway; 2Department of Energy and Process Engineering, Faculty of Engineering, Norwegian University of Science and Technology (NTNU), Kolbjørn Hejes vei 1a, 7034 Trondheim, Norway

As the existing building stock is responsible for high energy use and greenhouse gas emissions, energy upgrading projects have been acknowledged as crucial for the energy performance improvement in existing buildings, as well as for environment preservation and rational use of resources. The aim of this article is to investigate the definition of a nearly zero energy building (nZEB) level for the energy upgrading of dwellings. In particular, the findings from a research project, i.e., ''energy upgrading of wooden single-family houses to nearly zero energy level'' (OPPTRE), are presented and discussed. A core task of the OPPTRE project was to carry out an architectural competition, where six interdisciplinary teams proposed innovative solutions for upgrading to nZEB level six representative Norwegian wooden single-family houses, from the period 1950-1990. The upgrading measures proposed in the OPPTRE competition focused on several aspects, such as architectural quality, indoor thermal environment, energy use/production, carbon footprint, and cost effectiveness. General principles for the nZEB level achievement in the upgrading projects are discussed, as deducted from the evaluation of the results of the OPPTRE architectural competition. In particular, the focus in this article is on examining the solutions proposed for upgrading the building envelope and the technical building systems. The energy use, energy production, investment costs, and CO2 emissions across the various OPPTRE projects are examined, striving to define a trade-off among different parameters for the achievement of a nZEB level. The findings of this paper support the creation of knowledge for nearly zero-energy upgrading of wooden single-family houses, aiming to a more systematic definition of the nZEB level in such projects. This can be relevant for several stakeholders, such as governmental institutions, homeowners, builders, and private or public decision makers, for the market uptake of nZEB upgrading towards 2030.

Contact and Legal Notice · Contact Address:
Privacy Statement · Conference: IBPC 2021
Conference Software - ConfTool Pro 2.6.142+TC
© 2001 - 2021 by Dr. H. Weinreich, Hamburg, Germany