IEA SHC Articles

Assessing the impact of climate change on energy retrofit of alpine historic buildings: consequences for the hygrothermal performance
August 2020
By: L. Hao, D. Herrera, A. Troi, M. Petitta, M. Matiu and C. Del Pero

Climate change will affect future hygrothermal performance of buildings. This could lead to higher risks regarding energy optimization, thermal comfort and historic building conservation depending on the local climate, building construction and retrofit solutions adopted. This paper explores the risks brought by climate change on a typical residential historic building of South Tyrol. The results obtained show that, although the climate warming will reduce the future heating energy demand, an improvement of buildings' energy performance will still be necessary to increase sustainability and ensure their continued use. Natural ventilation would suffice to prevent overheating in the studied location, but a further analysis is needed for warmer alpine regions. Regarding the moisture-related risks for the historic construction, mould growth should be considered when retrofitting a wooden wall and frost damage should be carefully studied in the case of sandstone walls.

Click here to access the full version. 

Country Highlight: South Africa – Coal Out, Solar and Wind In
Country Highlight: South Africa – Coal Out, Solar and Wind In
December 2019 - PDF 1.11MB
By: Dr. Karen Surridge and Ms. Khothasto Mpeqeke of SANEDI and Ms. Karin Kritzinger of the University of Stellenbosch
Editor: Pam Murphy

South Africa is demonstrating its commitment to a more sustainable future growth path by supporting renewable energy and energy efficiency measures, together with skills development and job creation through fostering a green economy. South Africa is among the highest emitters of carbon dioxide in the world, currently ranked in the top 20 in terms of top emitters per capita, since more than 75% of our primary energy requirement is derived from fossil fuels. The country responded to the urgent need to reduce fossil fuel dependency, diversify the energy mix and supply, and reduce the country’s carbon footprint with a supportive policy and legislative framework that exploits the excellent local renewable energy resources, especially wind and solar.

New SHC Projects in 2020
New SHC Projects in 2020
December 2019 - PDF 0.35MB
By: Pam Murphy

New Task on Solar Process Heat Starts in January / Planning Underway for a Working Group on Life Cycle and Cost Assessment for Heating and Cooling Technologies / 

 

Portugal and Spain’s Innovative Solar Solutions for Waste Management in the Iberian Peninsula
Portugal and Spain’s Innovative Solar Solutions for Waste Management in the Iberian Peninsula
December 2019 - PDF 0.22MB
By: Miguel Miranda, João Cardoso, Pedro Azevedo, David Loureiro, Farinha Mendes and Victor Mantilla of LNEG

The SECASOL project is implementing innovative solar thermal solutions in wastewater sludge and municipal solid waste drying processes in southern Portugal and Spain.
 

Quasi-Monte Carlo based uncertainty analysis: Sampling efficiency and error estimation in engineering applications
November 2019
By: Tianfeng Hou, Dirk Nuyens, Staf Roels, Hans Janssen
Publisher: Reliability Engineering & System Safety, Volume 191

In probabilistic assessment via Monte Carlo sampling efficiency is of high importance. It is shown that Quasi-Monte Carlo mostly performs better than standard Monte Carlo. Depending on the smoothness of the function and the number of dominant parameters. Randomization techniques on Quasi-Monte Carlo allows assessing sampling accuracy.In probabilistic assessment via Monte Carlo sampling efficiency is of high importance. It is shown that Quasi-Monte Carlo mostly performs better than standard Monte Carlo. Depending on the smoothness of the function and the number of dominant parameters. Randomization techniques on Quasi-Monte Carlo allows assessing sampling accuracy.

Click here to access the full version.

To learn more information about the project RIBuild, click here.

Trilemma of historic buildings: Smart district heating systems, bioeconomy and energy efficiency
November 2019
By: Andra Blumberga, Ritvars Freimanis, Indra Muizniece, Kriss Spalvins, Dagnija Blumberga
Publisher: Energy, Volume 186

Novel insulation material made from pine needles based on bioeconomy principles is tested. Insulation material without/with lime treatment was tested for application as internal insulation for historic buildings. Insulation material is highly porous, has high moisture transfer and storage capacity, and is good hygric regulator. No mold growth was detected at 85% relative humidity for lime treated samples.

Get full access to the publication here.

Neural networks for metamodelling the hygrothermal behaviour of building components
September 2019
By: Astrid Tijskens, Staf Roels, Hans Janssen
Publisher: Building and Environment, Volume 162

A metamodel with a memory mechanism is required to accurately predict hygrothermal time series. Recurrent neural networks and dilated causal convolutional networks are able to capture the complex patterns of the hygrothermal response. To predict the relative humidity, dilated causal convolutional neural networks perform significantly better than recurrent neural networks. Dilated causal convolutional networks are 10 times faster to train on the current example, compared to recurrent neural networks.

Get access to the full publication here.

The effects of wind-driven rain on the hygrothermal conditions behind wooden beam ends and at the interfaces between internal insulation and existing solid masonry
August 2019
By: Tessa Kvist Hansen, Søren Peter Bjarløv, Ruut Peuhkuri
Publisher: Energy and Buildings, Volume 196

Wind-driven rain (WDR) quantification performed experimentally on 2 case buildings. Effect of WDR on hygrothermal conditions in internally insulated masonry studied. Numerical simulations to determine WDR effect on hygrothermal performance. WDR models were found to overestimate WDR deposition. Direct influence of WDR events on RH behind insulation was not detected.

The full publication can be found here.

Energieaktive Fassaden
Nachhaltige Technologien 2/2019
May 2019
Editor: AEE INTEC

Issue of technical journal „nachhaltigen technologien“ presenting an overview of current research and dissemination activities on "Energy active facades" (German language)

Hygric properties of porous building materials (IV) Semi-permeable membrane and psychrometer methods for measure moisture storage curves
April 2019
By: Chi Feng, Hans Janssen
Publisher: Building and Environment

The moisture storage curve is an important hygric property of porous building materials. It describes the moisture storage characteristic of a material via the relation between the moisture content and the moisture potential. Current experimental protocols for measuring moisture storage curves are not satisfactory, as they often require extensive facilities while still lacking the capability to handle the adsorption process in most of the over-hygroscopic range. This paper proposes two novel and simple methods – the semi-permeable membrane method and the psychrometer method – to solve these issues. Measurements on calcium silicate, autoclaved aerated concrete and ceramic brick are performed and validated by comparing the experimental outcomes obtained from these two novel methods and from other existing protocols. It is proven that the semi-permeable membrane method and the psychrometer method are applicable for both adsorption and desorption processes, the latter both from saturated and capillary moisture content. Limited by the accuracy of the psychrometer and the condensation caused by temperature fluctuations, these two methods show their best applicable range for capillary pressures below −1·105?Pa. The semi-permeable membrane method and the psychrometer method also feature in low cost, simple handling and application efficiency.

Click here for full article.

Hygric properties of porous building materials (IV) Semi-permeable membrane and psychrometer methods for measuring moisture storage curves
April 2019
By: Chi Feng, Hans Janssen
Publisher: Building and Environment, Volume 152

Two novel methods for measuring the moisture storage curves are proposed. They feature in wide applicable range, low cost, simple handling and efficiency. Both adsorption and desorption in the over-hygroscopic range can be measured. Tests on 3 representative porous building materials are performed and validated.

For access to the full publication click here.

Effect of temperature and relative humidity on algae biofouling on different fired brick surfaces
February 2019
By: Enrico Quagliarini, Andrea Gianangeli, Marco D'Orazio, Benedetta Gregorini, Andrea Osimani, Lucia Aquilanti, Francesca Clementi
Publisher: Construction and Building Materials, Vol. 199

Microalgae biofouling on different porous and rough fired brick surfaces was studied. Its growth under different values of relative humidity and temperature was tested. At relative humidity lower than 98% no growth was present. Temperature influenced algae growth rate and covered area as a function of time. Biofouling experimental results were modelled by a modified Avrami’s law.

Click here for full access to the publication.

Advanced thermal storages - towards higher energy densities, long term storage and broader operating ranges
Advanced thermal storages - towards higher energy densities, long term storage and broader operating ranges
December 2018 - PDF 0.19MB
Publisher: IEA SHC Task 58
As the share of renewables in energy production grows so does the role for thermal energy storage. The wide range of applications for thermal energy storage presents a broad range of development conditions for advanced thermal storage technologies to supplement the existing, widely used water-based heat storage technologies. Thermal energy storage could reveal itself as a real game-changer, allowing for a notable decrease in primary energy demand, thus reducing the energy footprint. It could also support the widespread acceptance and use of renewable energy as well as the efficient use of fluctuating energy sources.
Building Experts at EuroSun 2018 Discuss What’s Being Done and What Needs To Be Done
Building Experts at EuroSun 2018 Discuss What’s Being Done and What Needs To Be Done
December 2018 - PDF 0.21MB
By: Matteo D’Antoni

The 12th EuroSun International Conference on Solar Energy for Buildings and Industry was a big success. On September 10th to 13th, more than 130 oral and 180 poster presentations were given to an audience of researchers, professionals, and experts from all over the world in Rapperswil, Switzerland.

Country Highlight: Portugal - Sun & Innovation Drive Change
Country Highlight: Portugal - Sun & Innovation Drive Change
December 2018 - PDF 1.44MB
By: Maria João Carvalho, João Farinha Mendes
Publisher: IEA SHC
Portugal has one of the highest solar energy resources in Europe, but the solar thermal market in Portugal is not in line with this fact as can be seen in the most recent publication of the IEA SHC’s Solar Heat Worldwide (see Figure 2). Portugal’s cumulated installed capacity is lower than in other European countries with much lower solar resources.
Interview with Daniel Mugnier: New Generation Solar Cooling & Heating Systems
Interview with Daniel Mugnier: New Generation Solar Cooling & Heating Systems
December 2018 - PDF 1.06MB
Publisher: IEA SHC Task 53
The IEA SHC Programme concluded its work on New Generation Solar Cooling & Heating Systems (Task 53) earlier this year and is now finalizing the last reports. To learn first-hand on how the Task supported the market development of the next generation of solar driven cooling and heating systems, we asked Daniel Mugnier, the Task Operating Agent, to share some of his thoughts on this 3-year project.
Next Generation Solar Cooling & Heating Systems
Next Generation Solar Cooling & Heating Systems
December 2018 - PDF 0.49MB
By: Daniel Mugnier, Bärbel Epp
Publisher: IEA SHC Task 53
For the IEA SHC, we’ve long seen this ever-growing demand for cooling as an opportunity for solar technology and an area for international collaboration. Our most recent solar cooling Task is winding down. For the past four years, an international team of researchers worked on 1) solutions to make solar driven heating and cooling systems cost competitive and 2) building a sustainable and robust market for new innovative solar thermal and PV cooling systems. (Task’s results continue to be posted on the Task webpage task53.iea-shc.org). Both of these goals require methods for assessing and evaluating the technical and economic potential of the technology and benchmarking against conventional systems and different renewable technologies. Two tools developed to do just this are T53E4 and ELISA.
Solar Standards and Certification
Solar Standards and Certification
December 2018 - PDF 0.13MB
Publisher: IEA SHC Task 57
As 2018 comes to an end so does our most recent Task on Solar Standards and Certification. SHC Task 57 built on the work of Task 43 on Solar Rating and Certification Procedures to develop, improve and promote ISO standards on test procedures and requirements for solar thermal products as well as to harmonize at the international level certification schemes. It is this harmonization work that sets this Task apart from our other work and the work begin carried out by other organizations. Task 57 participants leveraged the SHC platform of international collaboration to push a global certification initiative to improve the harmonization of certification schemes and avoid the need for re-testing and re-inspection of solar thermal products.
Outdoor characterization of colored and textured prototype PV façade elements
Outdoor characterization of colored and textured prototype PV façade elements
Proceedings of 35th European Photovoltaic Solar Energy Conference and Exhibition EU PVSEC 2018, Brussels
November 2018 - PDF 0.67MB
By: Tzikas C., Valckenborg R., van den Donker. M., Bognar A., Duque Lozano D., Loonen R.C.G.M., Hensen, J.L.M., Folkerts. W.
Document Number: https://doi.org/10.4229/35thEUPVSEC20182018-6AO.8.

Abstract - The aim of this study is to assess the performance of prototype PV façade elements of various PV technologies, colors and textures. Within this context, a prototype PV façade demonstrator was constructed and monitored at SolarBEAT, Eindhoven. This prototype demonstrator consists of 9 façade PV panels of c-Si and CIGS technologies with flat and textured solar glasses and black, grey and red colors. The field-testing results indicate a limited performance drop of less than 20% for all colors and textures.

Advanced daylighting systems and combined lighting and thermal simulation
Advanced daylighting systems and combined lighting and thermal simulation
13th Conference on Advanced Building Skins, Oct. 1-2, 2018, Bern, Switzerland, website: abs.green
October 2018 - PDF 0.34MB
By: David Geisler-Moroder, Christian Knoflach, Silvia Öttl, Wilfried Pohl

Abstract - As the interface between interior and exterior spaces, the façade plays a key role for the thermal and visual conditions in buildings. Advanced daylighting systems should fulfill various and in parts contradictory requirements: they must provide sufficient and adequately distributed natural lighting, avoid visual discomfort (glare) while allowing visual contact to the exterior, provide solar gains for heating in winter and protect from high radiation against overheating in summer. Integrating these functionalities often results in products which are more complex than conventional sunshading systems and thus are often not properly characterized and cannot be applied in standard design workflows. We present approaches for the characterization of advanced daylighting systems and introduce DALEC, a simplified tool for combined lighting and thermal simulations that can account for such systems. (...)

Building Retrofit Measures and Design: A Probabilistic Approach for LCA
October 2018
By: Claudio Favi, Elisa Di Giuseppe, Marco D’Orazio, Marta Rossi and Michele Germani
Publisher: Sustainability

This paper presents a new and structured approach to address uncertainty and sensitivity analysis in Life Cycle Assessment (LCA) to support the decision-making process in building renovation. This “probabilistic” approach to LCA allows for the obtaining of results expressed as ranges of environmental impacts and for alternative solutions, offering an idea of the meaning of input parameters’ uncertainties and their influence on the result. The methodology application is illustrated through a case study where three building retrofit measures were assessed. Results provide an insight about the uncertainties of LCA indicators in terms of climate change and non-renewable energy.

Please visit MDPI for the full publication.

Building retrofit using facade-integrated energy supply systems
Building retrofit using facade-integrated energy supply systems
ISEC - International Sustainable Energy Conference, Congress Graz, Austria, 03.-05. October 2018
October 2018 - PDF 1.08MB
By: Dagmar Jaehnig, Thomas Ramschak, David Venus, Karl Hoefler, Christian Fink

Abstract - A new approach of highly-efficient thermal refurbishments of multi-family buildings is presented that has a high potential to reduce costs and simplify the renovation processes significantly. This approach is based on prefabricated curtain wall elements that integrate components for the energy supply system such as heat pumps, PV panels and all the necessary pipework for supply and waste water lines. By using pre-fabricated curtain wall elements, scaffolding and the relocation of inhabitants can be avoided. Three different system concepts have been evaluated and compared to a reference retrofit in terms of primary energy and life cycle costs. It has been shown that the new concepts can reduce the primary energy consumption significantly while reducing the costs over the lifetime of the system. Finally, a functional mockup of such as pre-fabricated façade was constructed and successfully tested in the laboratory.

Characterization of advanced daylighting systems and combined lighting and thermal simulation
Characterization of advanced daylighting systems and combined lighting and thermal simulation
13th Conference on Advanced Building Skins, Bern, Switzerland, Oct. 1-2, 2018 - website: abs.green
October 2018 - PDF 0.34MB
By: David Geisler-Moroder, Christian Knoflach, Silvia Öttl, Wilfried Pohl

Abstract - As the interface between interior and exterior spaces, the façade plays a key role for the thermal and visual conditions in buildings. Advanced daylighting systems should fulfill various and in parts contradictory requirements: they must provide sufficient and adequately distributed natural lighting, avoid visual discomfort (glare) while allowing visual contact to the exterior, provide solar gains for heating in winter and protect from high radiation against overheating in summer. (...) We present approaches for the characterization of advanced daylighting systems and introduce DALEC, a simplified tool for combined lighting and thermal simulations that can account for such systems. A comparison between DALEC and TRNSYS proves that the simplified approach is adequate for integrated simulations in early design phases.

Deep renovation of a MFH with decentral compact heat pumps
Deep renovation of a MFH with decentral compact heat pumps
ISEC - International Sustainable Energy Conference, Congress Graz, Austria, 03.-05. October 2018
October 2018 - PDF 1.3MB
By: Fabian Ochs, Dietmar Siegele, Toni Calabrese, Georgios Dermentzis

Abstract - Within the framework of the Austrian FFG project “SaLüH!” concepts with high energy efficient and cost-effective decentral small scale heat pumps for heating and DHW preparation for the renovation of small dwellings in multi-story buildings are developed and investigated. Very compact heat pumps are developed in order to enable the integration of these units into the window parapet or into the façade. The wall integration has a high potential in pre-fabrication and leads to an optimal solution for renovation of small apartments. The target is to create a complete renovation package with a decentralized (apartment size) exhaust-air heat pump (HP) for ventilation and heating installed in the kitchen and an air-to-water HP for DHW preparation installed in the bathroom. The solutions aim to be cost effective, involving components and technologies with high efficiency and minimum noise emissions. (...)

Living in Light – a transformation concept of existing buildings
Living in Light – a transformation concept of existing buildings
13th Conference on Advanced Building Skins, Oct. 1-2, 2018, Bern, Switzerland, website: abs.green
October 2018 - PDF 0.7MB
By: Jakob Klint, Vickie Aagesen

Abstract - The intension of Living in Light is to create additional space behind a more transparent and flexible building envelope in a transformation of existing buildings. The purpose is to make a more demand driven concept for renewal and transformation of existing buildings to the benefit of the users, the owners and the environment. The transparent building envelope adds new qualities to the building. A part from more space it creates a “Summer Garden”, with daylight and better indoor environment, active facades (PV and thermal sun power) and better energy performance. The Living in Light Box tests the concept. www.livinginlight.info | Paper | Presentation

Solar thermal façade systems – An interdisciplinary approach
Solar thermal façade systems – An interdisciplinary approach
13th Conference on Advanced Building Skins, Bern, Switzerland, Oct. 1-2, 2018 - website: abs.green
October 2018 - PDF 0.74MB
By: P.-R. Denz, P. Vongsignha, S.F. Haeringer, T.E. Kuhn, C. Maurer, M. Hermann, H. Seifarth, K. Morawietz

Abstract - To reach future Net-Zero Energy Buildings as requested by the “Energy Performance of Buildings Directive” the integration of systems for harvesting of renewable energy is decisive. Building integrated solar thermal (BIST) collectors can play an important role in this paradigm shift. In the R&D projects ArKol and TABSOLAR multidisciplinary teams develop different BIST systems for transparent and opaque facades. These solutions help trigger highly qualitative architectural integration of solar thermal collectors and are planned for future realization. This paper describes the basic layout of these systems and the current state of development.
 

Combining multi-view photogrammetry and wireless sensor networks when modelling the hygrothermal behaviour of heritage buildings
September 2018
By: S. Dubois, M. de Bouw, Y. Vanhellemont, D. Stiernon and S. Trachte
Publisher: EEHB 2018

The construction sector has now entered the ‘Digital era’, and professionals are slowly getting familiar with many of these innovative technologies. This paper shows how such innovations improve the investigation phase when it comes to energy retrofits on heritage buildings. More specifically, multi-view photogrammetry and wireless sensor networks can facilitate the implementation and enhance the relevance of building hygrothermal and energy simulations: photogrammetry quickens up the reproduction of the building geometry whereas wireless sensor networks facilitate and enlarge the collection of data relative to the existing behaviour of an occupied building. This paper explores the benefits of using those two technologies compared to more traditional solutions, regarding data quality and general workflow. In this purpose, two case studies from research projects ongoing in Belgium are briefly described.

Click here for the full version, p. 156.

Decision support tool for the innovative and sustainable renovation of historic buildings (HISTool)
September 2018
By: W. Hüttler, D. Bachner, G. Hofer, M. Krempl, G. Trimmel and I. Wall
Publisher: EEHB 2018

The HISTool is a software-based tool for the analysis of the current building status, and a decision support tool for the innovative and sustainable renovation specifically of Gründerzeit buildings. These were built between 1840 and 1918 with partially standardized designs and components in CentralEuropean cities. The tool is designed to be applied particularly in the preparation and decision-making stage of renovation projects in the Gründerzeit building sector, prior to the actual planning phase. For the decision-making process, it is essential to provide solid data on different renovation options in an early phase based on life-cycle costs, without a lot of calculation effort. The calculation is based on a model of the building, which consists of 40 elements according to the specifics of Gründerzeit buildings and the selection of predefined renovation measures. The integrated energy performance and life-cycle cost calculation leads to the derivation of life-cycle costs of different renovation variants. A comparison of life-cycle costs of different renovation options leads to information-based renovation decisions. The aim is to stimulate the Gründerzeit sector in the real estate market to implement more energy-efficient and innovative renovations, which are compatible with the specific requirements of historic buildings, and to contribute to the fulfilment of the climate-protection goals. HISTool particularly reflects the environmental and economic goals of sustainable management of historic buildings according to EN 16883, and supports the planning and decision making procedure in the first phase as well as in the detailed planning phase when it comes to the selection of specific measures and assessment against the initial project targets.

Click here for the full version, p. 227.

Energy savings due to internal façade insulation in historic buildings
September 2018
Editor: Tor Broström, Lisa Nilsen and Susanna Carlsten
Publisher: EEHB 2018

The paper presents desktop analyses of potential energy savings in historic buildings, carried out using standard boundary conditions for calculation of energy savings, as prescribed in the European building energy performance certification schemes. Internal insulation of the building’s façades can potentially reduce the theoretical energy demand for space heating by 9 to 43 % compared to the energy demand of the original building if installed moisture-safe. Combined with other commonly used energy saving measures, 43–78 % reduction of the energy demand was estimated.

Click here for the full version, p. 24.

How to estimate material properties for external walls in historic buildings before applying internal insulation
September 2018
By: E.J. de Place Hansen and E.B. Møller
Editor: Tor Broström, Lisa Nilsen and Susanna Carlsten
Publisher: EEHB 2018

Before deciding how to improve the energy efficiency of historic buildings by applying thermal insulation, an estimation of consequences, e.g. changes in heat and moisture flux, must be made. In the EU-project RIBuild, attempts have been made to cluster historic building materials; enabling a user to choose an appropriate material and include uncertainties. Unfortunately, the decisiveness of properties depended on whether e.g. conditions at external or internal surface of the brick wall were considered.

Click here for the full version, p. 43.

Outlining a methodology for assessing deterioration threshold criteria
September 2018
By: L. Lång, P. Johansson, C-M. Capener, H. Janssen, J. Langmans, E. Møller, M. D’Orazio and E. Quagliarini
Editor: Tor Broström, Lisa Nilsen and Susanna Carlsten
Publisher: EEHB 2018

This paper describes a methodology for assessing damage threshold criteria. The methodology includes a survey and determination of threshold values for deterioration, which can then be used to evaluate the risk in specific structures of external walls. The work includes summarizing existing knowledge and adapting and developing models for failure modes based on field and laboratory testing. Failure modes include frost damage of the exterior façade layer, rot and mould growth within the building envelope and adjoining structures, as well as discolouring of façade surfaces due to biological growth.

Click here for the full version, p. 34.

Potentialities and criticalities of different retrofit guidelines in their application on different case studies
September 2018
By: V. Pracchi and A. Buda
Publisher: EEHB 2018

The paper aims to investigate criticalities and potentialities of the Italian Cultural Heritage Ministry’s Guidelines (October 2015) and the European Guidelines for Improving Energy Performance of Historic Buildings (EN 16883 – June 2017), comparing and applying them to selected case studies. The documents represent an instrument to help public authorities and designers to follow an iterative retrofit process; in both cases it is possible to notice some difficulties in their technical application. Thus, we have identified their critical and positive features through the case studies assessment. The scope is to underline possible issues and to suggest new solutions in both cases, improving the existing guidelines with other targets to obtain a calibrated evaluation method, which could guide the retrofit project.

Click here for the full version, p. 285.

Removable textile devices to improve the energy efficiency of historic buildings
September 2018
By: V. Pracchi, E. Rosina, A. Zanelli and C. Monticelli
Publisher: EEHB 2018

The paper aims to present innovative studies concerning removable devices for enhancing thermal performance or mitigating criticalities in listed buildings. The first concerns a “high tech” curtain studied for preventing air drafts from the windows, causing different forms of decay in the Sala delle Asse in Castello Sforzesco (Milano), world known for the Leonardo Da Vinci fresco. The second body of research deals with a new type of “arazzo” (removable and usable seasonally) to improve the insulation of the walls. The study case regards the collection of historic “arazzi” in Sala della Balla, in Castello Sforzesco as well.
The focus is to investigate how the main properties of the removable devices  affect the thermal exchange with the air and the surfaces where they are applied. A third study case is a masterpiece of listed modern architecture, Casa del Fascio in Como, where the new uses require cooling with the addition of a shadowing system.

Click here for the full version, p. 129.

The “Waaghaus” of Bolzano
September 2018
By: D. Exner, M. Larcher, A. Belleri, A. Troi and F. Haas
Publisher: EEHB 2018

The present paper analyzes the renovation project of a heritage medieval building located in the city center of Bolzano–the “Waaghaus”. The building has been used as case study in the EU-project 3encult, where it has been extensively studied both from heritage and energy efficiency points of view. Our analysis, partly based on the experience gained in the EU-project, aims at validating and improving the renovation project that was developed by a design team commissioned by the owner. In particular three aspects of the renovation are mainly investigated: 1) Reduction of the energy demand 2) Indoor climate and air quality 3) Hygrothermal risk in critical points. Results show that the proposed renovation cuts the energy demand to 60 percent. Moreover they demonstrate that, when renovating a historic building, it is crucial to carefully investigate the ventilation strategy and the critical construction details. Not considering these two aspects can lead to poor air quality and to a significant risk of surface mould and condensation formation.

Click here for the full version, p. 137.

The effect of climate change on the future performance of retrofitted historic buildings
September 2018
By: L. Hao, D. Herrera and A. Troi
Publisher: EEHB 2018

Historic buildings account for more than one quarter of Europe’s existing building stock and are going to be crucial in the achievement of future energy targets. In order to ensure their endurance, conservation compatible solutions are needed. Nevertheless, some alteration in the climate is already certain and therefore the impact of climate change on retrofitted historic buildings should be considered in terms of occupants’ comfort, heritage conservation, and energy performance. Inappropriate interventions might weaken the potential of original passive climate adaptive system, such as thermal mass and night cooling, leading to higher risks of overheating. Similarly, retrofit solutions will change the moisture dynamics of historic envelopes, which might lead to moisture damages when combined with more extreme precipitation events. This paper reviews recent literature that provides evidence of climate change’s impact on retrofitted buildings, reveals potential future risks, and thereby throws light on new factors influencing the retrofit decision-making process.

Click here for the full version, p. 62.

What’s behind the façade?
September 2018
By: G. Leijonhufvud, M. Tunefalk and M. Legnér
Publisher: EEHB 2018

Energy efficiency policies might have a negative impact on the heritage values of buildings, an issue widely recognized in Sweden during and after the extensive energy efficiency programme ‘Energy savings plan for existing buildings’ (EBB 1977–84). The purpose of this paper is to assess the long-term impact of the EBB on an urban district in Gävle, Sweden. The district comprises 69 single- and multi-family detached houses built between the 1920’s and 1950’s. Using archival sources and field studies we describe how the buildings have been modified and trace the role of the EBB on the district as a whole. The results show that despite that the EBB has had a major impact on the district, it is difficult to disentangle its role in relation to other factors. The study raises concerns over the common approach in policy making to draw distinct lines in the sand between heritage and non-heritage buildings.

Click here for the full verison, p. 193.

Concept for adaptive wall elements with switchable U- and g-value
Concept for adaptive wall elements with switchable U- and g-value
VIII Int. Congress on Architectural Envelopes, June 20-22, 2018, Donostia-San Sebastián, Spain
June 2018 - PDF 0.42MB
By: Nikolaus Nestle, Thibault Pflug, Christoph Maurer, Frank Prissok, Andreas Hafner, Frank Schneider

Abstract - This contribution will present a concept for (translucent) wall elements with switchable U- and g-values. The basic concept of the element consists of an insulation panel (preferably realized by a translucent and light-guiding foam grid or in the future by transparent vacuum glazing) which is arranged inside a glazed closed cavity so that thermally driven convection around the element can either be enabled or suppressed. Supression of convection is realized by a rollable second insulation inside the cavity which can reflect incident solar radiation: If the secondary insulation is fully retracted resulting in high U and g-value and daylight being guided inside the building. By successively rolling down the insulation, convection can be suppressed and the g-value can be varied from almost unchanged to almost zero. In the case of the secondary insulation being rolled fully down, the U-value of the element is also minimal. This state is favourable in a cold winter night or during hot daytime hours in summer. The high translucence, low-U-value case is favourable in conditions where solar gains and good insulation are favourable and the translucent high-U-value case is favourable for example in a summer night to cool the building (...).

Low Temperature Solar Thermal System for Building Envelope Integration
Low Temperature Solar Thermal System for Building Envelope Integration
VIII Int. Congress on Architectural Envelopes, Donostia-San Sebastián, Spain, June 20-22, 2018
June 2018 - PDF 0.53MB
By: Marina Palacios, Roberto Garay, Ignacio Gomis, Paul Bonnamy, Saed Raji, Koldobika Martin

Abstract - In this article it is presented an innovative façade system with a solar thermal system. The developed solar system can be classified as modular unglazed collector, designed for low temperature energy capture. It is compatible with a solar combined system that integrates a solar heat pump. The external appearance of the building remains untouched thanks to this innovative system. Experimental works at façade collector level are presented. The integration of the unglazed collector in a heat pump based combined solar system, its performance levels and economic figures are presented.

Simulation-based performance prediction of an energy-harvesting façade system with selective daylight transmission
Simulation-based performance prediction of an energy-harvesting façade system with selective daylight transmission
VIII Int. Congress on Architectural Envelopes, Donostia-San Sebastián, Spain, June 20-22, 2018
June 2018 - PDF 0.6MB
By: Saini, H., Loonen, R.C.G.M., Hensen, J.L.M.

Abstract - Shading devices are effective in controlling glare and solar heat gains in buildings. However, this occurs at the expense of daylight and outside view. This paper evaluates the thermal and daylight performance of Lumiduct, a sun-controlling dynamic façade system that permits only diffuse radiation inside the building, while producing electricity. This imparts Lumiduct a unique characteristic of acting as a shading device while providing useful daylight and view to the outside. The first part of the paper briefly illustrates the working principle of Lumiduct and its functional characteristics and then, introduces the basic principles of the modelling and simulation strategy used to predict its performance. (...) The results show a significantly higher daylight utilization along with a reduction in glare and energy use for heating and cooling the building.

Fassadengekoppelte Energieversorgungskonzepte für die Sanierung
Fassadengekoppelte Energieversorgungskonzepte für die Sanierung
February 2018 - PDF 0.32MB
By: D. Jähnig, C. Fink, T. Ramschak, D. Venus, K. Höfler

Abstract  - Im Rahmen des von 2014 bis 2017 laufenden Projektes „Vorgefertigte Fassadenelemente mit maximal integrierten HVAC-Komponenten und -systemen zur Bestandssanierung“ wurden neue Lösungsansätze für intelligente Bestandssanierung aufgezeigt bzw. entwickelt, wobei es unter anderem um die Synergieeffekte für die Modernisierung der Gebäudehülle und der Gebäudetechnik bei konsequenter Nutzung erneuerbarer Energieträger ging. Erklärtes Ziel dabei war die Erreichung eines hohen Vorfertigungsgrades in Verbindung mit Holz- Vorhangfassaden und damit kurze Sanierungszeiten mit geringsten Belastungen der Bewohner, reduzierte Abhängigkeiten von der Witterung im Sanierungsprozess sowie eine gesichert hohe Ausführungsqualität. Entsprechende Energieversorgungskonzepte stellen die auf die Fassade auftreffende Solarenergie effizient dem Gebäude zur Verfügung.

Heat Decarbonization - What Role can Solar Thermal Play?
Heat Decarbonization - What Role can Solar Thermal Play?
December 2017 - PDF 0.09MB
Heat accounts for more than half of global final energy consumption. However, heat production remains heavily fossil-fuel based and is a significant contributor to CO2 emissions, accounting for 39% of total annual energy-related emissions globally. To achieve the ambitious targets of the Paris climate change agreement, heat decarbonization is a must. But what role can solar thermal play?
Is Solar Thermal a Viable Solution for a Future Renewable Energy System?
Is Solar Thermal a Viable Solution for a Future Renewable Energy System?
December 2017 - PDF 0.13MB
Solar thermal integration might in some situations be counter-beneficial for a renewable transition, especially when considering an energy system supplied by high shares of renewable energy. This is one of the conclusions from a study performed by Aalborg University as part of SHC Task 52 on Solar Heat and Energy Economics in Urban Environments. This conclusion was reached by performing a series of energy system analyses under various conditions of four national energy systems in Germany, Austria, Italy and Denmark. The solar thermal potentials were identified for each country today and in a future energy system converted to 100% renewable sources in the heating and electricity sectors. However, mixed results were found regarding the impacts on economy, environment and energy consumption when installing these solar thermal potentials.
Large Scale Solar Installations – The Actors & Activities
Large Scale Solar Installations – The Actors & Activities
December 2017 - PDF 0.22MB
Industry and researchers are collaborating to assess how best to integrate large scale solar thermal installations in combination with hybrid technologies into district heating and cooling networks. Besides the international scope of this work, what also makes it unique is that the IEA SHC Programme has teamed up with the IEA District Heating and Cooling Programme to ensure that the right stakeholders are involved.
Solar Energy in Urban Planning: Interview with Maria Wall
Solar Energy in Urban Planning: Interview with Maria Wall
December 2017 - PDF 0.25MB
The IEA SHC Programme is finishing its work on Solar Energy in Urban Planning (Task 51). To learn first hand about the impact Task 51 has had in this field, we asked Maria Wall, the Task Operating Agent, a few questions as a teaser before next year’s wrap-up article on the Task’s results.
IEA SHC Task 54: Solar Thermal Cost Reductions
November 2017
By: Eva Augsten
Publisher: Solarthermalworld.org

The objective of IEA SHC Task 54 is to reduce the purchase price of solar thermal systems by up to 40 % across the entire value chain. To achieve this, the project partners have been evaluating technical and non-technical cost-saving potential, with low-cost materials, such as polymers, and production technologies bound to play an important role. At an early October workshop in Linz, Austria, about 50 project partners and guests discussed cost reductions made possible by new distribution channels, digital solutions and systems thinking approaches.

Switchable Windows - Spectral Transmission and Switching Times
Switchable Windows - Spectral Transmission and Switching Times
ISES Solar World Conference and Solar Heating Conference. Abu Dhabi, United Arab Emirates (UAE), 29.10.-02.11.2017
November 2017 - PDF 0.95MB
By: Lemarchand, P., McLean, E., Norton, B.

Abstract - The switching time and spectral transmission in fully clear and fully opaque states of polymer dispersed liquid crystals (PDLC), suspended particle device (SPD) and electrochromic (EC) switchable windows were evaluated to assess their suitability to control solar heat transmission though glazed façade and comfort to building occupants. The transmission measurement on a SPD film showed a very effective absorption modulation in the visible range but fast decrease in the near infrared region. The switching speed was demonstrated to be related strongly to wavelengths. A SPD film with a larger absorption and faster switching speed in the infrared region was shown to be preferable to control solar heat transfer through glazings and thermal comfort. The PDLC window did not modulate transmission but rather modulated scattering. In the opaque state, the PDLC window was highly scattering resulting in spectral transmission varying at short distances from the window while being constant in the far field ... [read full Abstract and Paper]

Laboratory Investigation of Latvian Historic Brick and Measurements of Water Movement in Historic Masonry Walls
May 2017
By: Reinis Purvins, Edite Biseniece, Andra Blumberga
Publisher: Energy Procedia

Experimental laboratory tests including density, water absorption, soluble salts, compressive strength and freeze-thaw resistance have been done on clay, concrete and silicate bricks from 6 masonry buildings in Latvia following CEN standards with adjustments for historic bricks. In addition, in-situ measurements of moisture content in brick masonry walls were done over a 5 month period using Trotec micro-wave apparatus.

Click here for access to the full article.

Performance assessment of an unglazed solar thermal collector for envelope retrofitting
Alternative and Renewable Energy Quest, AREQ 2017
February 2017
By: Roberto Garay Martinez, Beñat Arregi Goikolea, Ignacio Gomis Paya, Paul Bonnamy, Saed Raji, Jerôme Lopez

Abstract - Present trends on solar thermal systems for building integration define the need of integrated solar technologies for façades. Although other possibilities exist for solar thermal systems in new buildings, solutions for a suitable integration of solar thermal systems into building retrofitting actuations are needed. This paper presents a solar thermal collector system which hybridizes already existing ventilated façade cladding systems into a low temperature solar thermal collector. Numerical and experimental data is presented. Access full paper on Research Gate

Performance assessment of façade integrated glazed air solar thermal collectors
International Conference – Alternative and Renewable Energy Quest, AREQ 2017, 1-3 February 2017, Spain
February 2017
By: Roberto Garay Martineza, Julen Astudillo Larraza

Abstract - Present trends on solar thermal systems for building integration define the need of integrated solar technologies for façades. The integration of solar systems in façades allows for the direct connection of solar systems to heated spaces, and automated air solar collectors based on the trombe-mitchell provide a suitable technology for its adoption in multi-rise buildings with decentralized-individual HVAC systems in Central-European and Mediterranean heating dominated climates. This paper reviews the main principles of such building envelope components, and the construction and design considerations of two air-based solar thermal collectors. Full scale preliminary prototypes of these systems were tested at the KUBIK by Tecnalia test facility in an Oceanic Climate (Koppen Geiger Cfb zone). The observed thermal performance is analyzed, and the process of a full scale installation in a real building envelope retrofitting process of a building in Spain is reviewed. Access full paper on Research Gate

Advanced Lighting Solutions for Retrofitting Buildings
Advanced Lighting Solutions for Retrofitting Buildings
Interview with Jan de Boer
December 2016 - PDF 0.14MB
Editor: Pamela Murphy
Publisher: IEA SHC
The IEA SHC Programme wrapped up its work on Advanced Lighting Solutions for Retrofitting Buildings (Task 50) this year, and is developing a new Task on the topic of Integrated Solutions for Daylight and Electric Lighting: From Component to User Centered System Efficiency. To learn first hand about the impact Task 50 has had in this field, we asked Jan de Boer, the Task Operating Agent, a few questions.
Canadian Solar Community Hits 100% Solar Heating
Canadian Solar Community Hits 100% Solar Heating
December 2016 - PDF 0.3MB
Editor: Pamela Murphy
The Drake Landing Solar Community in Okotoks, Alberta hit a new solar performance milestone record – 100% solar space heating for the 2015-2016 heating season. This is the first community in the world to accomplish this feat. The community of 52 energy efficient homes is heated by a solar district heating system combined with a borehole seasonal heat storage designed to store abundant solar energy underground during the sunny summer months and recover this heat for space heating during the cold winter months.
European SDH Projects – The Next BIG Solar Step
European SDH Projects – The Next BIG Solar Step
December 2016 - PDF 0.14MB
Editor: Pamela Murphy
A team of experts from the city of Graz, Austria, has decided to take a lead in the analysis and evaluation of a major proposed local Solar District Heating (SDH) project to determine if it is technically feasible, is feasible within realistic costs, and if it will even be a profitable business opportunity.
Improving Lighting Retrofits
Improving Lighting Retrofits
December 2016 - PDF 0.66MB
Editor: Pamela Murphy
The recent IEA SHC Task on lighting set out to accelerate retrofitting of daylighting and electric lighting solutions in the non-domestic sector using cost effective, best practice approaches that could be used on a wide range of typical existing buildings.
Industry and Research Join Forces on Reliability Testing of Collectors and Materials
Industry and Research Join Forces on Reliability Testing of Collectors and Materials
December 2016 - PDF 0.13MB
Editor: Pamela Murphy
Publisher: IEA SHC

Solar thermal collectors and their components are commonly exposed to a wide range of climatic influences. Next to UV radiation, factors like humidity, wind, extremely high or low temperatures, salt, sand and other particles in the atmosphere affect the surfaces and performance of these products. Although these influences are decisive factors for the lifetime and long-term efficiency of solar thermal collectors, there are no validated or binding test procedures for reliability assessment over time or models that allow a location-specific service life prediction.

Slovakia Joins IEA SHC!
Slovakia Joins IEA SHC!
December 2016 - PDF 0.06MB
Editor: Pamela Murphy
IEA Solar Heating and Cooling Programme welcomes Slovakia as the first country from Eastern Europe to join the Programme. Participation by the Slovak Innovation and Energy Agency (SIEA) in the IEA SHC builds on collaboration by Slovakia in the Programme’s lighting retrofit work.
Solar Thermal in Qatar Today and Tomorrow
Solar Thermal in Qatar Today and Tomorrow
December 2016 - PDF 0.24MB
Editor: Pamela Murphy
In recent years, the population of Qatar has grown at an increased rate than was previously seen and so has carbon emissions. As the population has grown at a faster rate than previously seen and demand for resources that will result in further increases in the rate of carbon emissions. Considering the wider impacts of carbon emissions on our climate, it is vital to reduce these emissions using effective renewable solutions.
Nordic Built - Active Roofs and Facades and Living in Light urban renewal in Valby, Copenhagen
Nordic Built - Active Roofs and Facades and Living in Light urban renewal in Valby, Copenhagen
Task 56 session at 12th Conference on Advanced Building Skins, Bern, Switzerland, 02.-03.10.2016 - website: abs.green
October 2016 - PDF 0.56MB
By: Peter Veisig, Cenergia, Denmark

Abstract - In the on-going Nordic Built Living in Light project, coordinated by Kuben Management, a new concept of urban renewal will be tested at Gl. Jernbanevej in Valby in Copenhagen. Here a 4 storey old housing block from around year 1900 will have new roof top apartments together with an approx. 2 m extension of the housing block towards the courtyard. The extension mainly consists of an innovative window structure from the Danish window company Velfac, and it increases the daylight quality of the apartments considerably without compromising comfort and energy use. At the same time building integrated PV solutions secures an overall CO2 neutral design for the renovation project.

Prefabricated timber-frame envelopes for building retrofit with integrated ventilation, heating system & building services
Prefabricated timber-frame envelopes for building retrofit with integrated ventilation, heating system & building services
Task 56 session at 12th Conference on Advanced Building Skins, Bern, Switzerland, 02.-03.10.2016 - website: abs.green
October 2016 - PDF 1.2MB
By: Sebastian Hernandez, Gumpp & Maier, Germany; Fabian Ochs, University of Innsbruck, Austria

Abstract - The objective of the EC-funded project iNSPiRe is to reduce the problem of high-energy consumption of existing buildings by producing systemic renovation packages that can be applied to residential and tertiary buildings. The renovation packages aim to reduce the 2 primary energy consumption of a building to lower than 50 kWh/(m a) for ventilation, heating/cooling, domestic hot water and lighting. These renovation packages need to be suitable for various climates in Europe while ensuring optimum comfort for the building users. One major goal of iNSPiRe is the development of multi-functional renovation kits that make use of innovative envelope technologies, energy generation systems (including RES integration) and energy distribution systems [...]

2016 Solar Thermal Trends
2016 Solar Thermal Trends
May 2016 - PDF 0.18MB
By: Pam Murphy
With 2016 underway, it’s important to stop for a moment and think about where solar thermal is headed in the short-term and how current work can support or be adjusted to keep pace with technological advances. Several SHC Task Operating Agents have weighed in on trends in their areas of expertise.
ISES Joins IEA SHC!
ISES Joins IEA SHC!
May 2016 - PDF 0.52MB
By: Pam Murphy
The IEA Solar Heating and Cooling Programme welcomes the International Solar Energy Society (ISES) as its newest Sponsor member. This development offers expanded opportunities for ISES members to participate in technical activities under the IEA SHC, and places ISES at the IEA SHC table as a member of its Executive Committee.
Solar Rating & Certification
Solar Rating & Certification
Interview with Jan Erik Nielsen
May 2016 - PDF 0.12MB
By: Pam Murphy

The IEA SHC Programme wrapped up its work on Solar Rating & Certification (Task 43) in 2015, and in 2016 started a new Task on Solar Standards and Certification (Task 57). To get a better understanding of the impact of Task 43, we asked Jan Erik Nielsen, the Operating Agent, a few questions.

Task 42: Compact Thermal Energy Storage
Task 42: Compact Thermal Energy Storage
Collaboration Leads to Groundbreaking Work
May 2016 - PDF 0.68MB
By: Matthias Rommel
For the first time international teams of materials experts and application experts collaborated to tackle together issues confronting thermal energy storage. This one of a kind research platform was created jointly by the IEA Solar Heating and Cooling Programme (IEA SHC) and the IEA Energy Conservation through Energy Storage Programme (IEA ECES).
Task 49: Solar Heat in Industrial Processes
Task 49: Solar Heat in Industrial Processes
Interview with Christoph Brunner
May 2016 - PDF 0.14MB
By: Pam Murphy
Solar Update (SU): Why was this project needed? Christoph Brunner (CB): SHC Task 49/SolarPACES Annes IV: Solar Heat Integration in Industrial Processes was initiated to foster market penetration of this rather young technology that has large worldwide potential.
Task 53: The Future of Solar Cooling
Task 53: The Future of Solar Cooling
May 2016 - PDF 0.35MB
By: Daniel Mugnier
The increasing demand for refrigeration and air conditioning has led to a dramatic increase in peak electricity demand in many countries. With the increase in demand comes the increase in the cost of electricity and summer brownouts, which have been attributed to the large number of conventional air conditioning systems running on electricity. As the number of traditional vapor compression cooling machines grows (more than 100 million units sold in 2014) so do greenhouse gas emissions, both from direct leakage of high GWP refrigerant, such as HFCs, and from indirect emissions related to fossil fuel derived electricity consumption. An obvious counter to this trend is to use the same energy for generation of cooling that contributes to creating the cooling demand—solar energy.
Novel solar thermal collector systems in polymer design – Part 3: aging behavior of PP absorber materials
Novel solar thermal collector systems in polymer design – Part 3: aging behavior of PP absorber materials
2016 - PDF 0.43MB
By: Markus Povacz, Gernot M. Wallner, Michael K. Grabmann*, Susanne Beißmann, Klemens Grabmayer, Wolfgang Buchberger, Reinhold W. Lang
Publisher: Energy Procedia, Elsevier
A novel, accelerated aging test method was used to characterize the long-term stability of commercial black-pigmented polypropylene (PP) model materials for solar thermal absorbers at elevated temperatures. The PP model materials investigated, PP-B1 and PP-B2, are based on carbon black pigmented PP block copolymer grades. Using an automatized planning technique, sliced 100 µm thick specimens were prepared, aged in hot air and heat carrier fluid (mixture of 60 vol.-% deionized water and 40 vol.-% commercial propylene glycol) at 95°C, 115°C and 135°C for up to 15,000 hours, and characterized in terms of various aging indicators (i.e., remaining primary stabilizer content, oxidation temperature, carbonyl index and ultimate mechanical properties). In general two major trends were discerned. First, the aging processes of the PP compounds depend on the stabilizer system, but even more heavily on the interaction of the stabilizers with the carbon black pigments and the structure and morphology of the polymer. Although the compound PP-B2 exhibited much faster stabilizer loss and an associated drop in oxidation temperature than PP-B1, mechanical investigations proved a better long-term stability for PP-B2. Second, it was shown for the compounds investigated that exposure to hot air causes harsher aging than exposure to hot heat carrier fluid. This is, presumably related to the reduced quantity of dissolved oxygen and triazole-based corrosion inhibitors used in the heat carrier fluid. While PP-B1 is use for absorbers in unglazed collectors and overheating-protected glazed collectors, the investigations clearly revealed that PP-B2 is a promising alternative.
Novel solar thermal collector systems in polymer design – Part 5: Fatigue characterization of engineering PA grades for pressurized integrated storage collectors
Novel solar thermal collector systems in polymer design – Part 5: Fatigue characterization of engineering PA grades for pressurized integrated storage collectors
2016 - PDF 0.94MB
By: Joerg Fischer*, Patrick R. Bradler, Mathias Schlaeger, Gernot M. Wallner, Reinhold W. Lang
Publisher: Energy Procedia, Elsevier
A novel aging test method considering the superimposed mechanical and environmental (temperature and environmental medium) loads representative for pressurized integrated storage collectors (ICS) is described. Engineering polyamide (PA) grades with short glass fiber (GF) reinforcement, which are of high relevance for endcaps of steel-pipe ICS absorbers or all-polymeric absorber/storage-tanks, are characterized on a specimen level. Therefore, specific test devices and test arrangements for fracture mechanics specimens with or without weld-line are implemented on an electro-dynamic test machine. Fatigue crack growth kinetics data are obtained by conducting cyclic mechanical loads under various environmental testing conditions. The experimental results of two glass-fiber reinforced PA grades, using compact type specimens, performed at two different temperatures (23 °C and 80 °C) and in two environmental media (air and water), are compared in terms of crack growth kinetics. Moreover, the influence of welding on the crack growth kinetics for one PA grade is shown. For all specimens (unwelded and welded) the fatigue crack growth rates are enhanced in water compared to air. In welded specimens the fatigue crack growth resistance is significantly reduced compared to unwelded specimens.
Polymeric materials in solar-thermal systems - performance requirements and loads
Polymeric materials in solar-thermal systems - performance requirements and loads
2016 - PDF 1.91MB
By: Thomas Ramschak, Robert Hausner, Christian Fink
Publisher: Energy Procedia, Elsevier
A major basic problem in selecting appropriate polymeric materials and processing technology routes is related to the lack of well-defined functional and performance requirements on the component level and to material property requirements on the specimen level. Hence, in a first step several reference climate regions were defined for pumped systems (continental (Graz/Austria), moderate climate (Beijing/China)) and non-pumped systems (Mediterranean (Athens/Greece), hot and dry (Pretoria/South Africa), hot and humid (Fortaleza/Brazil)), respectively. For each of these reference regions various solar-thermal plant types (e.g., domestic hotwater systems for single family houses (pumped and thermosiphon); domestic hot-water systems for multi-family houses; solar combi-systems for domestic hot-water and space heating (pumped) were pre-defined and evaluated and optimized virtually by modelling and simulation. To determine performance requirements on the component level and to derive material property requirements on the specimen level all-purpose modelling and design tools for collectors were implemented and used which allow for the description of temperature profiles, stagnation conditions, efficiency curves, pressure losses, distribution of fluid and heat flow and the thermal and hydraulic optimisation of the whole collector.
Lifetime modeling of polypropylene absorber materials for overheating protected hot water collectors
Lifetime modeling of polypropylene absorber materials for overheating protected hot water collectors
January 2016 - PDF 0.48MB
By: G.M. Wallner, M. Povacz, R. Hausner, R.W. Lang
Publisher: Solar Energy, Elsevier

For the utilization of polymeric materials in high-demanding applications like solar thermal systems it is of utmost importance to define the performance requirements and to investigate the applicability of components for defined systems under service relevant conditions. This paper deals with the lifetime estimation of black-pigmented polypropylene (PP) absorber grades for overheating protected solar thermal collector systems for hot water preparation in five representative climate zones. Based on experimental aging data in hot air and heat carrier fluid at elevated temperatures (95 °C, 115 °C and 135 °C) and climatic input data, as well as deduced loading conditions and absorber temperature distributions, the lifetime was calculated using a theoretical and an empirical extrapolation approach and assuming cumulating damages in service relevant temperature intervals. Depending on the PP grade, the extrapolation method and the location, endurance limits ranging from 8 to 50 years were obtained. The PP grade with ß-spherulithic structures and less carbon black exhibited a superior performance (factor 2) compared to a well-established grade which is currently widely used for swimming pool absorbers.

A Fundamental Look At Supply Side Energy Reserves For The Planet
A Fundamental Look At Supply Side Energy Reserves For The Planet
November 2015 - PDF 0.15MB
By: Richard Perez, Atmospheric Sciences Research Center, University at Albany, Statue University of New York and Marc Perez, MGH-Energy
Publisher: IEA SHC
This is an update of the April 2009 Solar Update article. The objective of the 2009 article was to put in perspective the potential of often-cited nuclear and renewable alternatives to Greenhouse Gas (GHG) emitting fossil energy sources. Its main conclusion was that although a mix of alternatives, including hydropower, biomass/biofuels, geothermal, ocean thermal energy conversion, waves, tides, wind and solar, appeared like a sound approach to bringing about the desired economically and environmentally sustainable energy future (akin to putting future energy eggs in different baskets), a review of their potential clearly showed that the solar resource dwarfed all other renewables (and fossil/nuclear alike) by orders of magnitude. And therefore, the desired economically and environmentally sustainable energy mix of the future should be essentially solar-based.
Country Highlight: Spain - A Sunny Paradise Truncated by a Financial Crisis: The Building Code Experience
Country Highlight: Spain - A Sunny Paradise Truncated by a Financial Crisis: The Building Code Experience
November 2015 - PDF 0.24MB
By: Ricardo Enríquez Miranda, Ph.D., CIEMAT
Publisher: IEA SHC
In the recent past decades, Spain has pioneered two solar revolutions: mandatory inclusion of solar thermal in new and refurbished buildings and solar thermal electricity. The 2008 financial crisis deeply impact the industry and the future recovery and development will depend strongly on these and other adopted policies.
Solar Thermal = Savings of Over 118 Million Tons of CO2 Annually
Solar Thermal = Savings of Over 118 Million Tons of CO2 Annually
Solar Heat Worldwide
November 2015 - PDF 0.15MB
Publisher: IEA SHC
The IEA SHC Programme’s Solar Heat Worldwide is the most comprehensive publication on the global solar heating and cooling market. This year’s report includes data from 60 countries, or 95% of the solar thermal market and can be downloaded for free.
Task 46: Best Practices: Solar Irradiance Measurements with Rotating Shadowband Irradiometers (Summary from SHC Newsletter)
Task 46: Best Practices: Solar Irradiance Measurements with Rotating Shadowband Irradiometers (Summary from SHC Newsletter)
November 2015 - PDF 0.16MB
By: S. Wilbert, N. Geuder, M. Schwandt, B. Kraas, W. Jessen, R. Meyer, B. Nouri
Publisher: IEA SHC
Large-scale solar thermal projects, such as those producing industrial process heat for mining areas in Chile or district heating in Denmark, require diligent solar resource assessments. Unfortunately, high accuracy irradiance data are scarcely available in many regions, which are attractive for solar energy applications. This holds especially true for solar thermal technologies using concentrating collectors to produce high temperatures. For these systems, the focus of the resource assessment lies on direct normal, or beam irradiance (DNI). Satellite data can only be used in combination with ground data to estimate inter-annual variability and longterm mean values. Hence, new ground measurements have to be collected for projects using concentrating collectors, such as high temperature process heat or district heating systems. Read Full Report: http://task46.iea-shc.org/data/sites/1/publications/INSRSI_IEA-Task46B1_BestPractices-RSI_150819.pdf
Task 53: Solar Cooling 2.0 A New Generation Is Growing Up
Task 53: Solar Cooling 2.0 A New Generation Is Growing Up
November 2015 - PDF 0.17MB
By: Riccardo Battisti, Ambiente Italia
Publisher: IEA SHC
The September workshop on New Generation Solar Cooling & Heating Systems focused on the status of solar cooling technology research and market developments. About 40 professionals gathered in Rome for this half day event, which was organized by IEA SHC Task 53: New Generation Solar Cooling & Heating Systems and the German Eastbavarian Institute for Technology Transfer, OTTI e.V. the day before OTTI’s 6th International Conference on Solar Air-Conditioning. Participants learned first hand about the first outcomes of SHC Task 53 that began its collaborative work in March 2014 and includes the participation of ten countries from across the globe.
Task 54: Price Reduction of Solar Thermal Systems
Task 54: Price Reduction of Solar Thermal Systems
November 2015 - PDF 0.11MB
By: Michael Köhl, ISE Fraunhofer
Publisher: IEA SHC

Driving down the costs of solar thermal systems is not just about cheaper collector production. In fact, post-production processes, such as sales, installation and maintenance account for up to 50% of the price that end consumers pay. This new IEA SHC Task, Price Reduction of Solar Thermal Systems, will investigate these other factors and find ways to reduce systems costs. The Task’s kick-off meeting was hosted by Fraunhofer ISE in Freiburg, Germany the end of October. Researchers and industry representatives from all over the world participated.

Case Study: Twin wall sheet testing
Case Study: Twin wall sheet testing
IEA-SHC Task 39 INFO Sheet C7.4
May 2015 - PDF 0.38MB
By: Andreas Piekarczyk, Alyin Durson
When using polymeric materials for solar thermal flat plate collectors, one distinct difference in physical properties compels us to reinvent the absorber design. Due to the low thermal conductivity of polymeric materials, the absorber, in order to prevent local overheating and to increase the collectors’ efficiency, needs water contact throughout the whole surface. In general only few absorber designs fulfill this requirement, e.g. thin plastic film absorbers, tube absorbers or twin wall sheets. The latter two are in the focus of recent development due to mechanical stability and economic efficiency. In order to investigate changes in the mechanical properties of the used materials as closely to the product as possible suitable mechanical testing methods need to be applied. For pipes, methods to test different mechanical loads already exist, but for twin wall sheets none of these can be applied.
Country Highlight: Netherlands High Energy in a Low Country
Country Highlight: Netherlands High Energy in a Low Country
May 2015 - PDF 0.16MB
By: Lex Bosselaar
Within the next 20 years the supply of fossil fuels, mainly oil and gas, will not be sufficient to provide for the world’s economies. Anticipating this shortage, the Dutch government policy focuses on a completely sustainable energy supply system by 2050. Renewable heat and heat storage will be key issues to achieve this goal.
Task 40: What Market Adoption of NetZEBs Need
Task 40: What Market Adoption of NetZEBs Need
May 2015 - PDF 0.08MB
Editor: Pamela Murphy
To mainstream market adoption of NetZEBs, what is needed is a wide consensus on clear definitions and agreement on the measures of building performance that could inform “zero energy” building policies, programs and industry building practices, as well as design tools, case studies and demonstrations that would support industry adoption.
Task 49: Guidelines Developed for Process Heat Integration
Task 49: Guidelines Developed for Process Heat Integration
May 2015 - PDF 0.42MB
Editor: Pamela Murphy
Solar planners, energy consultants and process engineers now have access to a general procedure to identify and rank suitable integration points and solar thermal system concepts when integrating solar heat into industrial processes. The guidelines were developed within SHC Task 49: Solar Heat Integration in Industrial Processes.
Task 50: Bypassing Barriers to Lighting Retrofit: Is Solid State Lighting Already Changing the Game?
Task 50: Bypassing Barriers to Lighting Retrofit: Is Solid State Lighting Already Changing the Game?
May 2015 - PDF 0.24MB
By: Marc Fontoynont
In comparison with a lighting solution using fluorescent sources, Solid State Lighting (LED) comes with different technical, operational (maintenance) and economical parameters. Work within IEA SHC Task 50: Advanced Lighting Solutions for Retrofitting Buildings studied the impact of these fast changing parameters on lighting retrofits – intending to give sound advice to decision makers.
Task47: Non-Residential Building Renovation – The Potential, Opportunities and Barriers
Task47: Non-Residential Building Renovation – The Potential, Opportunities and Barriers
May 2015 - PDF 0.85MB
By: Fritjof Salvesen
A 50 - 90% reduction in heat consumption and a 50 - 70% reduction in overall energy demand are possible when renovating a building. Twenty exemplary renovation projects highlighted in SHC Task 47: Solar Renovation of Nonresidential demonstrate how this can be achieved. Two buildings of these buildings achieved the plus-energy standard and one of them received the highest possible BREEAM score of “Outstanding.” And, all these buildings used commercially available products and systems.
Turkey: Solar Era Is Just Beginning
Turkey: Solar Era Is Just Beginning
May 2015 - PDF 0.55MB
By: Dr. Bulent Yesilata
In parallel with its population and GDP growth, Turkey has been experiencing rapid demand growth in all segments of the energy sector for decades. Turkey is developing an integrated energy policy aimed at securing a reliable supply of energy, as well as achieving a low-carbon and environmentally sustainable future. Turkey also intends to promote employment and economic growth through its energy development. Solar energy plays a major role in Turkey’s renewable energy roadmap due to the fact that is geographically located the “solar band” region.
Development of an energy evaluation methodology to make multiplepredictions of the HVAC&R system energy demand for office buildings
Development of an energy evaluation methodology to make multiplepredictions of the HVAC&R system energy demand for office buildings
May 2014 - PDF 4.88MB
By: Jinkyun Choa, Seungho Shina, Jonghurn Kimb, Hiki Hong
HVAC&R systems are the most energy consuming building services, representing approximately half of the final energy use in the building sector. Despite their significant energy use, there is a lack of a consistent and homogeneous framework to efficiently guide research, mainly due to the complexity and variety of HVAC&R systems, but also to insufficient rigor in their energy analysis. Quantifying the energy consumption characteristics of HVAC&R system is complicated, because the energy savings provided by this system depend on various factors. This research evaluates energy consumption characteristics of HVAC&R systems, with the aim of establishing a common idea for the analysis of building energy efficiency. The objective of this study is to develop an energy evaluation methodology and a simple simulation program that may be used by engineers and designers to assess the effectiveness and economic benefits of HVAC&R systems. Our approach deals with the concept of HVAC&R system energy use aggregation levels that are composed of subsystems. To carry out a techno-economical estimation of HVAC&R systems considering different types of subsystems, the matrix combination analyzed, and a total of 960 HVAC&R systems can be implemented for a large-scale office building. The methodology of energy analysis that was carried out in this study highlights how to plan and design toward utilizing the most effective HVAC&R systems.
Simulation of a solar collector array consisting of two types of solar collectors, with and without convection barrier
Simulation of a solar collector array consisting of two types of solar collectors, with and without convection barrier
2014 - PDF 0.54MB
By: Federico Bava*, Simon Furbo, Bengt Perers
Publisher: Energy Procedia, Elsevier
The installed area of solar collectors in solar heating fields is rapidly increasing in Denmark. In this scenario even relatively small performance improvements may lead to a large increase in the overall energy production. Both collectors with and without polymer foil, functioning as convection barrier, can be found on the Danish market. Depending on the temperature level at which the two types of collectors operate, one can perform better than the other. This project aimed to study the behavior of a 14 solar collector row made of these two different kinds of collectors, in order to optimize the composition of the row. Actual solar collectors available on the Danish market (models HT-SA and HT-A 35-10 manufactured by ARCON Solar A/S) were used for this analysis. To perform the study, a simulation model in TRNSYS was developed based on the Danish solar collector field in Braedstrup. A parametric analysis was carried out by modifying the composition of the row, in order to find both the energy and economy optimum. © 2015 The Authors. Published by Elsevier Ltd. Peer-review by the scientific conference committee of SHC 2014 under responsibility of PSE AG.
Fulfillment of net-zero energy building (NZEB) with four metrics in a single family house with different heating alternatives
Fulfillment of net-zero energy building (NZEB) with four metrics in a single family house with different heating alternatives
September 2013 - PDF 2.13MB
By: Ayman Mohamed, Ala Hasan, Kai Sirén
This study aims to investigate the fulfillment of four Net Zero Energy Building (NZEB) balances, NZEB-PE, NZEB-site, NZEB-emission and NZEB-cost, considering the four metrics of primary energy (PE), site energy, CO2-eqemissions and energy cost, respectively, using weighting factors based on Finnish and international reference data. The study analyzes five conventional energy systems and seven biomassbased standalone and shared combined heat and power (CHP) systems. These systems are connected to a single family house located in Helsinki, Finland, with two energy efficiency levels: a standard house and a passive house, simulated by Trnsys software. The annual balance of the import and export of the operational thermal and electrical energies is applied. The simulated results indicate that the NZEB-emission, NZEB-PE, NZEB-cost, and NZEB-site are arranged in that order according to the ease of fulfilling the annual balance. Making the house high in thermal energy efficiency (or adding solar thermal collectors) for all the studied systems is a step towards achieving NZEB-PE, NZEB-cost, and NZEB-site. On the contrary, achieving the NZEB-emission by the shared CHPs connected to the standard house is easier than the passive house. The NZEB balance is more attainable by the shared CHPs than the standalone CHPs. The NZEB-PE is easier to achieve using the international factors than using the Finnish PE factors.
Development of an integrated solar-fossil powered steam generation system for industrial applications
January 2013
By: Bernd Hafner, Olaf Stoppok, Christian Zahler, Michael Berger, Klaus Hennecke, Dirk Krüger
Publisher: Elsevier, Energy Procedia
Solar Steam Cooking Made Possible in the Treacherous regions on Ladakh
January 2013
By: Thermax Solar
Publisher: EQ International April 2013 Issue, Page 57
Solar Thermal Marking New Frontiers
January 2013
By: Thermax Solar
Publisher: EQ International March 2013 Issue, Page 61
Nearly-zero, Net zero and Plus Energy Buildings – How definitions & regulations affect the solutions
Nearly-zero, Net zero and Plus Energy Buildings – How definitions & regulations affect the solutions
December 2012 - PDF 0.39MB
By: Karsten Voss, Igor Sartori, Roberto Lollini
The topic of Zero Energy Buildings (ZEBs) has received increasing attention in recent years, up to inclusion in strategic energy policy papers in several countries. However, despite the emphasis placed on the goals, the various ZEB definitions applied mostly remain generic and are not yet standardised.
Photovoltaics and Zero Energy Buildings: A New Opportunity and Challenge for Design
Photovoltaics and Zero Energy Buildings: A New Opportunity and Challenge for Design
October 2012 - PDF 1.21MB
By: Alessandra Scognamiglio and Harald N. Røstvik

Starting from the end of 2020, all new buildings will have to be Nearly Zero Energy Buildings (Nearly ZEBs—ED 2010/31/EU recast). This new ‘energy paradigm’ might be a revolution for architecture and for Photovoltaics (PV) too, but there are both cultural and technical obstacles to overcome. There is a need to re-think the way buildings are designed (integrating renewables for being ZE). There is a need to re-think the way PV is designed in buildings. PV will be gaining an increasing relevance in the ZEBs design, thanks to its features and potentialities (suitability for any kind of energy demand of the building, easiness of building integration, cost). In a ZEB scenario, PV is very suitable for generating energy, ‘on site’ and ‘at site’; this enlarges the perspective of use of PV from the architectural scale to a wider scale, including the space close to the building or even to the urban and landscape scale. In such a new context, the existing research on the relationships between PV and architecture, focusing mainly on the way the PV components are used in relation to the envelope (Building-integrated PV/Building-added (Attached) PV), is no longer sufficient. The authors envision possible formal results, opportunities and challenges, for the use of PV in ZEBs, as well as new research issues for the future relationships between PV and ZEBs from the architecture and landscape design point of view. Copyright © 2012 John Wiley & Sons, Ltd.

Net zero energy buildings: A consistent definition framework
Net zero energy buildings: A consistent definition framework
February 2012 - PDF 0.68MB
By: Igor Sartori, Assunta Napolitano, Karsten Voss
The term Net ZEB, Net Zero Energy Building, indicates a building connected to the energy grids. It is recognized that the sole satisfaction of an annual balance is not sufficient to fully characterize Net ZEBs and the interaction between buildings and energy grids need to be addressed. It is also recognized that different definitions are possible, in accordance with a country’s political targets and specific conditions. This paper presents a consistent framework for setting Net ZEB definitions. Evaluation of the criteria in the definition framework and selection of the related options becomes a methodology to set Net ZEB definitions in a systematic way. The balance concept is central in the definition framework and two major types of balance are identified, namely the import/export balance and the load/generation balance. As compromise between the two a simplified monthly net balance is also described. Concerning the temporal energy match, two major characteristics are described to reflect a Net ZEB’s ability to match its own load by on-site generation and to work beneficially with respect to the needs of the local grids. Possible indicators are presented and the concept of grid interaction flexibility is introduced as a desirable target in the building energy design.
Europe Asia Solar Cooling Gains Traction
January 2012
By: Bärbel Epp
Editor: Solarthermalworld
Publisher: Solarthermalworld
Large Japanese and Chinese companies have recently taken a greater interest in solar cooling. The photo shows an installation by Chinese company Jiangsu Huineng New Energy Technology (Huin), which started supplying solar cooling systems this year. New system kits help drive down costs, although investments in sorption chillers are still higher than for compression chillers. After the Intersolar Europe conference in Munich, Germany, and its dedicated solar cooling session, Uli Jakob, Vice President of the German sorption chiller association Green Chiller, noted: “Solar cooling was one of the highlights of the conference.”
Keeping Cool with the Sun
Keeping Cool with the Sun
Latest Developments on Solar Cooling and Task 48 Short Presentation
January 2012 - PDF 1.36MB
By: Daniel Mugnier (TECSOL) & Uli Jakob (SOLEM Consulting)
Publisher: International Sustainable Energy Review
Worldwide, the energy consumption required for cold and air conditioning is rising rapidly. Usual electrically driven compressor chillers (split units) have maximum energy consumption in peak-load periods during the summer. In the last few years in Southern Europe this has regularly led to grids working to maximum capacity and blackouts. In recent years, the sales figures of split units with a cooling capacity range of up to 5KW have risen rapidly. www.internationalsustainableenergy.com
Solar process heat for sustainable automobile manufacturing
January 2012
By: Oliver Iglauera, Christian Zahler
Publisher: Elsevier, Energy Procedia, Vol 30, Pages 775-782
IEA SHC Task 54 Investigating Cost Factors Along the Value Chain
By: Baerbel Epp
Publisher: Solarthermalworld.org

Researchers have worked intensively for one-and-a-half years across national borders to find ways of reducing the costs of solar thermal systems and making them more attractive to end users. The members of Task 54 of the IEA Solar Heating and Cooling Programme, Price Reduction of Solar Thermal Systems, have discussed the effects of standardised product designs or changes in product offerings on cost structures. They have also analysed the entire value chain from component manufacture to system assembly and installation to help identify cost-cutting potential. This is the first time that methods of Process Cost Analysis are being adapted for the solar thermal business.

Interview with Jan Erik Nielsen: Solar Standards and Certification
Interview with Jan Erik Nielsen: Solar Standards and Certification
PDF 0.2MB
Publisher: IEA SHC Task 57
The IEA SHC Programme will wrap up its work on Solar Standards and Certification (Task 57) this month. To learn first-hand of this Task’s impact on standards and certification of solar thermal systems, we asked Jan Erik Nielsen, the Task Operating Agent, to share some of his thoughts on this 3-year project.