E2VENT: development of a ventilated façade module, embedding a air renewal system (SMHRU) and a energy storage system (LHTES), smartly piloted (BEMs), for the renovation of residential buildings,

This paper investigates the public and professional attitudes towards an innovative energy efficient façade refurbishment system, in Mediterranean countries, including Greece, Italy and Spain. Two types of multiple choice questionnaires were developed and addressed to two different target groups: building professionals and users. The survey questionnaire was created so as to elicit information on the interviewee's background and explore attitudes and perceptions towards the proposed system. Results signify that both potential users and professionals are generally positive towards the system's energy performance; however, the increased cost of acquisition, maintenance issues and the replacement of natural ventilation by mechanical means consist significant constraints that induce hesitations for the users. Professionals are willing to apply a ventilated façade in a future project but the lack of the corresponding knowledge may be an important obstacle to face.

The building sector is responsible for more than 40% of the EU’s total energy consumption. To reduce the energy consumption in buildings and to achieve the EU’s fossil fuel saving targets for 2020 and beyond 2050, the energy efficient retrofitting strategies are critically important and need to be implemented effectively. This paper presents a dynamic numerical investigation of the energy performance of an innovative façade integrate-able energy efficient ventilation system (E2VENT) that incorporates a smart modular heat recovery unit (SMHRU) and a latent heat thermal energy system (LHTES). A number of component simulation models, including SMHRU, LHTES, Cladding and Building Energy Management System (BEMS), were developed and then integrated using the TRNSYS software which is an advanced building energy performance simulation tool. On this basis, sizing, optimisation and characterisation of the system elements including the HVAC system and insulation layer thickness were carried out. The overall energy efficiency of the E2VENT system and its impact on the energy performance of a post-retrofit building were then investigated. In particular, the heating and cooling energy performance of the E2VENT façade module was numerically studied at five different climatic conditions in Europe. Furthermore, the innovative E2VENT retrofitting was compared with traditional retrofittings in terms of the energy efficiency and primary energy savings. It was found that the innovative E2VENT solution can achieve 16.5–23.5% building primary energy saving and compared to the traditional retrofitting, the E2VENT solution can achieve two times less primary energy consumption. Thanks to this efficiency the development of this solution for buildings retrofit is promising.

Within the existing European building stock, a large share of the suburban multi-storey residential building stock was built in the 60’s-70’s, when there were only few or no requirements for energy efficiency. These buildings are characterized by very high energy consumption, low air quality due to poor ventilation, and low architectural value. In this context, the European project E2VENT, that started in January 2015, aims at providing new solution of retrofitting of residential building. The proposal is a modular and adaptable ventilated façade retrofitting system that integrates an energy efficient HVAC system. This paper first presents the concept of the E2VENT module, its architecture and how it is currently designed aiming at the reduction of the energy consumption and the improvement of not only the indoor air quality but also of the aesthetic of the building. Then the presentation focuses on the LHTES system, presenting its working principle, its thermal model and how it is designed in order to allow a daily thermal storage for both cooling and heating to allow the peak shaving. Three different PCM encapsulations are presented and discussed based on their efficiency calculated with a simple model but also on more practical considerations. Finally, the first prototypes are shown and the experimental protocol to be carried out is detailed.