Cascaded Thermodynamic and Environmental Analyses of Energy Generation Modalities of a High-Performance Building Based on Real-Time Measurements

Abstract

This study presents cascaded thermodynamic and environmental analyses of a high-performance academic building. Five different energy efficiency measures and operation scenarios are evaluated based on the actual measurements starting from the initial design concept. The study is to emphasize that by performing dynamical energy, exergy, exergoeconomic, and environmental analyses with increasing complexity, a better picture of building performance indicators can be obtained for both the building owners and users, helping them to decide on different investment strategies. As the first improvement, the original design is modified by the addition of a ground-air heat exchanger for pre-conditioning the incoming air to heat the ground floors. The installation of roof-top PV panels to use solar energy is considered as the third case, and the use of a trigeneration system as an energy source instead of traditional boiler systems is considered as the fourth case. The last case is the integration of all these three alternative energy modalities for the building. It is determined that the use of a trigeneration system provides a better outcome than the other scenarios for decreased energy demand, for cost reduction, and for the improved exergy efficiency and sustainability index values relative to the original baseline design scenario. Yet, an integrated approach combining all these energy generation modalities provide the best return of investment.

Lessons from unsuccessful energy and buildings sustainability actions in university campus operations

“…They may be clustered into four major factors for the unsuccess, and ranked according to the number of appearances: i) Technical. Distinct technical problems that may prevent the effective operation of the energy strategies are raised -the inefficiency of the systems (Dvorak et al, 2020;Fonseca et al, 2018;Kalkan et al, 2011;Pusat and Akkoyunlu, 2018;Ruth et al, 2019); the difficult, poor or inexistent maintenance (Forman et al, 2017;Koch, 2018) that may lead to the undesired deterioration of the equipment (Medrano et al, 2018); the mismatch between demand and supply in the case of RES (Kwan and Kwan, 2011;Wiryadinata et al, 2019); the low contribution of the action to the baseline improvement (Al Doury et al, 2020;Leon et al, 2020Leon et al, , 2018; the potential conflicts of adapting new technologies to historical buildings (Cho et al, 2020); or even the morphology of a campus that is not suitable for implementing a RES (Kwan and Hoffmann, 2010). Forman et al (2017) suggest some relevant factors which may cause the installed RES to only provide slight reductions in energy and emissions: the lack of post-occupancy evaluations by designers, due to the fact that projects are often commissioned externally and, therefore, there may be a gap between the estimated goals and the real performance in the use phase; and the organizational structures of institutions and the inappropriate attribution of competences and lack of skills among facility managers and maintenance staff.…”