Renewable Heating and Cooling Solutions for Buildings and Industry Workshop at Sustainable Places 2020

On 29th October 2020, HYBUILD organised and contributed to the largest workshop of Sustainable Places 2020 with 14 other sister-projects. Watch again the recording of this session !

Participating projectsSWS-Heating – HYBUILD – CREATE – TRI-HP – HYCOOL – SHIP2FAIR – SUNHORIZON – Heat4Cool – GEOFIT – SCORES – Innova microSolar – Hybrid BioVGE – RES4BUILD – SolBioRev – FRIENDSHIP

Chair of the workshopAndrea Frazzica (CNR ITAE) 
Participating European Commission representative: Olga RIO-SUAREZ, Policy Officer, DG Research & Innovation

Further details about this workshop at

Integrated Storage Systems for Residential Buildings at Sustainable Places 2020

On 29th October 2020, HYBUILD participated to the Integrated Storage Systems for Residential Buildings workshop at Sustainable Places 2020. Watch again the session !


Participating European Commission representative: Dominique Planchon, Senior Program Officer, DG Research & Innovation

Further details about this workshop at

3D renderings of the HYBUILD Almatret demo site

HYBUILD coordinator COMSA has developed simplified BIM models of the Spanish Almatret demo site to support the installation of the hybrid storage system which is progressing.

Follow the progress of the Spanish installation as well as the 2 other HYBUILD pilot sites in Cyprus and Austria on their photo albums here.

Techno-Economic Analysis of a Heat Pump Cycle Including a Three-Media Refrigerant/Phase Change Material/Water Heat Exchanger in the Hot Superheated Section for Efficient Domestic Hot Water Generation

A new journal publication presenting HYBUILD outcomes has just been released !

Integration of a three-media refrigerant/phase change material (PCM)/water heat exchanger (RPW-HEX) in the hot superheated section of a heat pump (HP) system is a promising approach to save energy for domestic hot water (DHW) generation in multi-family houses. The RPW-HEX works as a desuperheater and as a latent thermal energy storage in the system. The latent thermal energy storage is charged during heating and cooling operation and discharged for DHW production. For this purpose, the water side of the RPW-HEX is connected to decentralized DHW storage devices. DHW consumption, building standards and climate, energy prices, material costs, and production costs are the constraints for the selection of the optimal storage size and RPW-HEX design. This contribution presents the techno-economic analysis of the RPW-HEX integrated into an R32 air source HP. With the aid of experimentally validated dynamic computer models, the optimal sizing of the RPW-HEX storage is discussed to maximize energy savings and to minimize the investment costs. The results are discussed in the context of a return of investment analysis, practical implementation aspects and energetic potential of the novel technology.

Profit after 20 years of operation for (a) Case #1 (passive house located in Helsinki) and (b) Case #2 (low energy building located in Strasbourg). Markers “▼”, “●” and “▲” denote small (140 L), medium (210 L) and large (280 L) decentralized DHW storage devices. Please note that for some cases, no profit can be made after 20 years of operation, so they are not shown in the figures.

Read the full article

Energy assessment based on semi-dynamic modeling of a photovoltaic driven vapour compression chiller using phase change materials for cold energy storage

A new journal publication presenting HYBUILD outcomes has just been released: Solar cooling systems are a promising solution for reducing the electrical consumption of conventional building cooling systems. Among various alternatives, photovoltaic driven vapour compression chillers are currently the most mature and economically feasible solar cooling technology. This study focuses on the semi-dynamic modelling of a vapour compression chiller coupled with a novel refrigerant-phase change material (PCM)-water heat exchanger (RPW-HEX) which replaces the conventional chiller’s evaporator, allowing the efficient storage of the produced cooling energy. A custom-build lumped parameter model was developed in TRNSYS and was used to assess the performance of the proposed system on annual basis. Using as benchmark a conventional PV driven vapour compression chiller with electrical storage, the retrofitted hybrid storage system showed improved performance, limiting the cooling demand peaks and enhancing the solar fraction, especially for partial cooling loads. Last, a comparison of the PCM thermal energy storage to conventional batteries was carried out, leading to enhanced performance characteristics for the latter.

Read more here

Sustainable Places 2020 is next week

It is still time to join us at Sustainable Places by registering here !

HYBUILD is proud to have led the organisation of the Renewable Heating and Cooling Solutions for Buildings and Industry Workshop, in cooperation with 14 other sister-projects.

HYBUILD will also contribute to the Integrated Storage for Residential Buildings workshop led by the Ministor project.

Read the full programme of the conference at

Identification of Phase Fraction–Temperature Curves from Heat Capacity Data for Numerical Modeling of Heat Transfer in Commercial Paraffin Waxes

A new journal paper presenting HYBUILD results has been released in the Energies journal.

The area-proportional baseline method generates phase fraction–temperature curves from heat capacity data of phase change materials. The curves describe the continuous conversion from solid to liquid over an extended temperature range. They are consistent with the apparent heat capacity and enthalpy modeling approach for the numerical solution of heat transfer problems. However, the curves are non-smooth, discrete signals. They are affected by noise in the heat capacity data and should not be used as input to continuous simulation models. This contribution proposes an alternative method based on spline approximation for the generation of consistent and smooth phase fraction–temperature, apparent heat capacity–temperature and enthalpy–temperature curves. Applications are presented for two commercial paraffins from Rubitherm GmbH considering heat capacity data from Differential Scanning Calorimetry and 3-layer-calorimetry. Apparent heat capacity models are validated for melting experiments using a compact heat exchanger. The best fitting models and the most efficient numerical solutions are obtained for heat capacity data from 3-layer-calorimetry using the proposed spline approximation method. Because of these promising results, the method is applied to melting data of all 44 Rubitherm paraffins. The computer code of the corresponding phase transition models is provided in the Supplementary Information.

Read the full paper here.

Evaluation of thermal comfort and energy performance of a case study in vernacular architecture of Cyprus

A new conference paper by University of Cyprus – FOSS Research Centre for Sustainable Energy – was presented at the PLEA 2020 conference – Sustainable Architecture and Urban Design.

The conservation and rehabilitation of buildings of vernacular architecture is a sustainable approach, not only because it leaves a small ecological footprint, compared to the erection of new buildings, but also due to the passive bioclimatic design features integrated in vernacular buildings. This paper will investigate the thermal performance of vernacular architecture in lowland area in diverse climatic contexts.

HYBUILD demo site in Aglantzia, Cyprus

The findings of the current research are based on an on-site investigation carried out in a representative vernacular building that is going to be upgraded to a hands-on technology exhibition area of renewable energy systems complimented with visual means to enhance the experience of visitors under a Research European Programme (Horizon 2020). The current study provides a basis for the formulation of a site-specific design strategy to improve thermal conditions and achieve energy conservation within lowland constructions in diverse climatic conditions. Understanding and analysing the thermal behaviour of these spaces is the first step towards this strategy. The quantitative analysis reveals the various challenges faced and opportunities provided by lowland structures and contributes to informing current design policies. Moreover, the analysis will inform the sizing of the technical systems throughout the year.

Read the full paper here

HYBUILD Austrian pilot

Work is ongoing at the Langenwang Austrian pilot, to prepare the installation of the HYBUILD hybrid storage system.

The continental climate system will be installed at this pilot site. The maximum heating power consumption expected after the foreseen retrofitting operations is 10 kW. The following technologies will be applied in the building: PV, PCM thermal latent storage, Heat pump.

Drone flight for PV planning
Cooling ceiling installation
Electrical preparation for PV integration
Preparation for the heat pump outdoor unit
Technical room entrance

Evaluation of in-situ coated porous structures for hybrid heat pumps

One of the main limitations for the wide diffusion of sorption systems, either as stand-alone and in hybrid configurations, is the low heat transfer inside the adsorber, as well as the low volumetric cooling power.

In this context, HYBUILD partners (CNR ITAE, AKG, Fahrenheit and Mikrometal) have just released a new scientific paper which reports the experimental activity on four different advanced configurations for the adsorber, based on microchannel heat exchangers where the gap between the channels is filled with porous structures where zeotypes of SAPO-34 family were synthetized.

The porous structures evaluated are high-density fins, two different aluminium foams and compressed chips from the waste of aluminium machining. The sorption dynamic and cooling power density of each structure were measured through a Gravimetric Large Temperature Jump testing apparatus.

Detail of the structures used in the adsorbers. (a) chips; (b) foam#2

The results obtained showed that the best-performing configuration is the one with high-density fins, that, for a 90/30/20 °C cycle showed a Specific Cooling Power up to 1.1 kW/kg. The other structures exhibit a much slower adsorption process, corresponding to power densities of about 0.3 kW/kg. The results were used for sizing a full-scale adsorber, whose expected Volumetric Cooling Power is 500 kW/m3.

Full-scale adsorber HEX

Read the full paper here.