Guidelines for ITES design

ITES represents the thermal buffer to equilibrate different and non-synchronous thermal energy requirements. At building and daily scale, the ITES functionality can be provided by an underfloor or wall heating/cooling system and the novel PV/T solution (WP1), all enhanced with suitable PCMs (WP2). At seasonal and building footprint, the function can be supplied by means of horizontal ground heat exchangers (HGHEs) backfilled with an environmentally friendly mixture between PCMs and soil, blow moulded HDPE containers or by another application. This improvement will perform an Underground Thermal Energy Storage (UTES) into the very shallow ground, to meet the energy requirement of different climate zones (heating/cooling). Both solutions work with the largest and most massive elements available at building scale (floor/wall, ground), and therefore with the most suitable parts for thermal storage functions. For daily ITES, the PCM selection carried out in WP2 will be implemented according to the specific building elements, to maximize performance, minimize costs and avoid user impacts (installation, maintenance, decommissioning). Especially, methods and technologies will be studied for refurbishing cases, since that represents the main application. To this end, different building stocks and climate zones will be taken into account to classify different technologies, according to the wide literature about the topic. (Song et al., 2018, Lu et al., 2017, Ostrý et al.2016) As for the ground heat exchanger (GHE), the novel flat-panel technology will be adopted, since it combines the highest energy performance of shallow GHEs with a suitable shape for exploiting the PCMs mixture. Flat-panel is an EU patent pending of UNIFE (EP2418439A2) and has been already tested in several ground-source HP systems. Because its coupling with PCMs was only numerically analysed , a smart test rig will be designed and tested at lab scale, to check the performance of different kinds of installations (Micro-Macro encapsulated, blow moulded HDPE containers) of the PCMs selected in WP2, in coupling with the most common urban soil textures for UTES, both in cooling and heating needs. Similar applications are still not well studied in literature, especially for shallow ground which is largely affected by the weather. The main goal of this task is to provide guidelines for ITES solutions according to building energy requirements, costs, architectural and environmental limits. This will be completed under task 3.1.