Thermal performance optimization of building floors under air-conditioning intermittent operation by numerical simulation

Abstract

Under air-conditioning intermittent operation, there may be the large difference of air temperatures in two adjacent rooms due to different operation behavior, and thereby, interior envelops may cause great heat loss. Under this condition, floors may become the most vulnerable spot of the room heat preservation due to their large proportion in interior envelops and poor thermal insulation. To optimize the thermal performance of floors, three floor models were built to compare their thermal performance characteristics under air-conditioning intermittent operation, while a heat transfer model was built by the finite volume method and verified by experimental data. The results showed that an expanded polystyrene layer located close to the upper surface can improve the thermal performance of the bottom floor, while the continuous integration of an air space ceiling placed close to the lower surface can improve the thermal performance of the top floor obviously. The daily cooling load formed by the cast-in-place-reinforced concrete floor integrated with the expanded polystyrene layer and the air space ceiling can reduce the daily cooling load by 53.27% and 47.00%, compared with the cast-in-place-reinforced concrete floor and the cast-in-place-reinforced concrete floor only integrated with the expanded polystyrene layer.

Multi-objective optimization of kinetic facade aperture ratios for daylight and solar radiation control

“…Unlike Germany’s heating-dominant climate, which benefits from increased solar radiation for thermal comfort, the climatic conditions in Taipei require a different approach to facade design. In this context, the primary challenge is to optimize natural lighting while simultaneously minimizing the effects of direct solar exposure, due to the pervasive hot and humid conditions (Meng et al, 2019). Therefore, understanding the interaction between kinetic facades and Taipei’s climatic conditions could yield crucial insights into the optimization process.…”

Optimization of air-conditioning load due to different thermal parameters for a residential building using different techniques

“…24 A building can achieve improved thermal performance for both its bottom floor and top floor by strategically integrating an air space ceiling near the lower surface and an expanded polystyrene layer close to the upper surface. 25 The thermal conductivity of EPS varies between 0.038 and 0.037 W/(m-K) for densities between 16 and 35 kg/m 3 respectively. 26 Glass windows are the major energy users for heating and cooling in modern buildings, and the energy consumption can be reduced by 37% for office buildings after using window design parameters such as window size, window directions and glass material.…”

“…24 A building can achieve improved thermal performance for both its bottom floor and top floor by strategically integrating an air space ceiling near the lower surface and an expanded polystyrene layer close to the upper surface. 25 The thermal conductivity of EPS varies between 0.038 and 0.037 W/(m-K) for densities between 16 and 35 kg/m 3 respectively. 26…”

A weighted multi-objective optimisation approach to improve based facade aperture sizes in terms of energy, thermal comfort and daylight usage

“…The single optimisation approaches focus mostly on energy performance to find the optimum building shape, facade (Li et al, 2018; Tuhus-Dubrow and Krarti, 2010), window types (Lee et al, 2013), window orientation and window-to-wall ratio (WWR) (Susorova et al, 2013) and building orientation (Kwon et al, 2018). Second, the life-cycle cost has been considered as the single objective to optimise, in addition to infiltration (Ferdyn-Grygierek and Grygierek, 2017) and insulation thickness and layers of the envelope (Axaopoulos et al, 2019; Ferdyn-Grygierek and Grygierek, 2017; Kumar et al, 2020; Meng et al, 2019; Yılmaz and Oral, 2018, 2019). Moreover, few studies took thermal comfort (Baglivo et al, 2017) or daylight performance (Gagne and Andersen, 2012) into optimisation as the single objective.…”