Third Project Review

On 29th of February 2016, the EASEE project, lasting 4 years since the 1st of March 2012, will be concluded. Starting from R&D activities, technological prototypes became technical products to be validated first at small scale and then at large scale, first in laboratory then applied at test facades and finally installed in real residential buildings (called hereafter demo buildings).

In the following, the potential impacts for the future developments of the EASEE project are assessed on the basis of technical performances measured at the different demo sites for the solutions developed. As such, the impacts the project can deliver is assessed on the basis of the performances demonstrated in the different real dimension installations.

Test Facades

The first practical implementation of the project results was performed by installing prototypes on a test façade where their performances could have been evaluated in a "controlled" real environment. In particular, prototypes for indoor and cavity wall retrofitting were installed and monitored, while the first trial of external retrofitting consisted in the installation of thirteen panels of different textures and colors produced and installed (with no scaffoldings) on the selected test façade in Milan, and their energy behavior properly monitored.

Concerning the cavity and the inner retrofitting, the improvement due to the developed solutions in thermal conductance and, consecutively, thermal transmittance of the wall has been calculated by both by Average Method and by dynamic analysis, before and after retrofit. A decrease in U-value of 44.26% for the advanced perlite boards, 39.40% for the permeable insulating wallpaper and 24.12% for the flat laminated panel has been obtained with respect to the base wall. For the hydrophobized loose perlite the improvement was equal to 89.17 %.

Moreover, from hygro-thermal analysis performed concerning inner retrofitting, it has been also noticed that the kits had a positive effect on indoor climate in winter thanks to an average rise of 1.5°C, while the most interesting result was concerning the relative humidity among the three kits in which a difference of 10% RH at the cold side was visible in winter. During summer the difference was minimum.

Concerning the test facade external retrofitting, the improvement due to the developed solution (prefabricated insulating panels) in terms of thermal transmittance of the wall has been calculated using the Average Method before and after retrofit. It has been noticed from the data and the thermal photos that the prefabricated panels attenuated the heat flux reducing the energy losses and the thermal bridges. In particular, according to the monitoring campaign performed, a decrease in U-value of 68.88% was found.

Moreover, because of the thermal inertia of the panels, the external solution allowed to reduce the internal ambient air temperature during summer. Thus, the test façade was able to slow the rate at which the sun heats the office space.

Activities at test façade level allowed the consortium not only to evaluate the thermal performances and the hygro-thermal behavior of the solutions, but also to investigate on potential improvements on their production/manufacturing process as well as to test and optimize their installation procedures (primarily for what concern the external retrofitting panels).

Demo buildings

Core part of demonstration activities performed within the project was the validation of the EASEE approach towards energy efficiency at large scale through the retrofitting of existing residential buildings. Indeed, according to the procedure developed for the building structural and energetic diagnostic, the envelope of the selected demo buildings have been assessed, identifying geometrical structure and mapping thermal bridges through thermo-camera. All relevant non-technical parameters and indicators have been also collected. The design of the retrofitting intervention though EASEE solutions have been performed with the support of Retrofitting Planner and Design Tool as well as BIM software as a further validation of the proposed approach. Generally, the owners of the demo buildings have been involved in the retrofitting process design and intervention from the very beginning.

Based on the retrofitting design, the EASEE technical solutions have been manufactured, and all the other materials necessary for the external envelope, cavity and interior insulation have been produced and transported close to the demo sites. Installation of external components, cavity insulation and interior retrofitting on parts of the buildings has been carried out by the partners responsible for each demo, according to the guidelines provided within the project.

In particular, three residential buildings in three different countries have been selected towards the validation of the whole external retrofitting approach. Forty EASEE panels have been produced and installed at a residential building in Poland (Gdansk) providing a decrease in U-value of more than 75% with respect to the base wall. The rest of the building has been retrofitted through a traditional approach (ETICS) in order to compare not only the energy performances of the two approaches but also the installation procedures. In particular, a reduction of 50% of installation duration of EASEE panels compared to traditional approach has been experienced. Moreover, it has been demonstrated that the EASEE panels enhanced the building indoor comfort in winter, by increasing the indoor temperature of 1°C without altering the heating supply system, also thanks to the solar reflectance of the EASEE panels that improved reflectance of the building itself more than twice with respect to traditional retrofitting (e.g. ETICS).

One of the façade of a residential house in Spain (Madrid) has been retrofitted as well, not only acting on the exterior envelope but also on the cavity wall by injecting advanced Expanded Perlite properly hydrophobized. The Design Tool was used and validated both in Spain and in Poland for the optimization of the panels, minimizing the number of shapes required and highlighting the critical points where specific solutions for the joints have to be adopted, according to the building and manufacturing process requirements.

In this case, a noticeable improvement in the U/value was achieved with the combined solutions installed. In comparison with the initial wall configuration of the building, a reduction of 62% in the U/value of the retrofitted wall through perlite injection was calculated. The external retrofitting reduced the U/value from the same façade of 56.3%. The combination of the two retrofitting solution resulted in a reduction of more than 80% in the U-value from the original brick wall. From simulations carried out according to the new procedure for the energy certification of existing building (published by IDEA) the retrofitting intervention provided satisfactory outcomes in terms of energy efficiency improvements. Primary energy for heating has decreased of 37% (from 159 KWh/m2y to 99 KWh/m2y), providing also a reduction of 38% in heating emissions.

Last but not least, a residential multi-storey building in Italy (Milan) has been entirely retrofitted. The design saw the installation of 186 EASEE panels with different colors and textures (for a total of 28 typologies). Building envelope assessment using 3D laser scanning techniques has been used for acquiring a very detailed model and geometrical relief of the building for anchoring systems installation onsite. The Retrofitting Planner was used in order to evaluate expected cost, performance and return on investment to be validated through sensor data.

In comparison with the initial wall configuration of the building, a reduction of 67% in the U/value of the retrofitted wall has been calculated from the data available during monitoring campaign. This meant reduced energy consumption and higher thermal comfort. Indeed, the monitoring campaign showed an improved thermal internal behavior due to the increased efficiency of the building envelope. The combination between thermal mass and thermal insulation allowed the reduction of the inner temperature variation during the complete cycle of thermal charge and discharge of the envelope.

According to simulations performed through the Retrofitting Planner, the energy performance is expected to be improved of about 15% and the payback time after process optimization (1,5 years from the end of the project) is calculated of 9 years.

Retrofitting of almost 600 square meters lasted less than 3 months, avoiding the scaffolding and thus minimizing the annoyances of building occupants. Indeed, informal interview to building occupants highlighted a very good feedback on the renovation from both thermal comfort and aesthetics point of view.

Concerning the cavity wall retrofitting, two dedicated demo buildings have been built in Greece (Athens) at Lavrion Technological and Cultural Park where Expanded Synthetic Perlite (ESP) and Hydrophobized Natural Expanded Perlite (NEP) have been injected respectively in the East and South wall and performance compared against cavity wall without insulation and wall retrofitted with XPS. Monitoring started in October 2015.

Concerning solutions for the interior retrofitting, two of the advanced indoor insulation solutions were also installed in a room at Politecnico of Milan in order to test the application of the proposed solutions to walls with the same complexity that may be encountered in practice (window openings, corners, shutter boxes, doors, etc.). Installation of the most promising kit for interior retrofitting has been also performed at the Polish demo building (in the attic).