Energetic and economic analyses of integrating enhanced macro-encapsulated PCM’s with active underfloor hydronic heating system

Abstract

Phase change materials proved their capability of enhancing buildings’ thermal inertia and improving occupants’ thermal comfort. More attention was triggered by the scientific community as the use of thermal energy storage systems kept evolving in the building sector. Previous experimental investigations examined the effectiveness of enhanced macro-encapsulated coconut oil bio-based PCM integrated with underfloor water radiant heating system in two similar small-scale test facilities that are modular. The current study focuses on performing comparative energetic and economic analyses of the system performance in regards to: weather conditions, PCM application, PCM type and properties, and PCM plates position at the underfloor. Results highlighted the effectiveness of utilizing coconut oil PCM in active floor, and passive wall and roof as load shifting and energy savings were obtained. It was shown that with the combination of active and passive systems, annual savings of 227 USD can be achieved; and by placing the PCM underneath the heating system, energy saving of 393.5 kWh was achieved corresponding to 169 USD annual savings. However, 32 USD annual saving was achieved by the system integrated with paraffin wax compared to that integrated with cocoa-nut oil PCM. Finally, the PCM capability in cost savings was reflected with the payback periods being evaluated as follows: 6.82 years for experiment 2, 6.75 years for experiment 3 (both encountering load shifting), and 3.94 years for experiment 4 (encountering energy saving).