The development of adaptive building envelope technologies, and particularly of switchable glazing, can make significant contributions to decarbonisation targets. It is therefore essential to quantify their effect on building energy use and indoor environmental quality when integrated into buildings. The evaluation of their performance presents new challenges when compared to conventional “static” building envelope systems, as they require design and control aspects to be evaluated together, which are also mutually interrelated across thermal and visual physical domains. This paper addresses these challenges by presenting a novel simulation framework for the performance evaluation of responsive building envelope technologies and, particularly, of switchable glazing. This is achieved by integrating a building energy simulation tool and a lighting simulation one, in a control optimisation framework to simulate advanced control of adaptive building envelopes. The performance of a photovoltachromic glazing is evaluated according to building energy use, Useful Daylight Illuminance, glare risk and load profile matching indicators for a sun oriented office building in different temperate climates. The original architecture of photovoltachromic cell provides an automatic control of its transparency as a function of incoming solar irradiance. However, to fully explore the building integration potential of photovoltachromic technology, different control strategies are evaluated, from passive and simple rule based controls, to optimised rule based and predictive controls. The results show that the control strategy has a significant impact on the performance of the photovoltachromic switchable glazing, and of switchable glazing technologies in general. More specifically, simpler control strategies are generally unable to optimise contrasting requirements, while more advanced ones can increase energy saving potential without compromising visual comfort. In cooling dominated scenarios reactive control can be as effective as predictive for a switchable glazing, differently than heating dominated scenarios where predictive control strategies yield higher energy saving potential. Introducing glare as a control parameter can significantly decrease the energy efficiency of some control strategies, especially in heating dominated climates.
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Energy-saving potential of 3D printed concrete building with integrated living wall
Large-scale concrete 3D printing and digital construction has brought enormous potential to expand the design space of building components (e.g., building envelope) for the integration of multiple architectural functionalities including energy saving. In this research, a modular 3D printed vertical concrete green wall system – namely the 3D-VtGW, was developed. The 3D-VtGW envelope was assembled with prefabricated (3D printed) multifunctional wall modular elements, which serves as the enclosure of the building as well as the backbone for a green wall system to improve building’s energy efficiency. Using this design concept and large-scale concrete 3D printing, a prototype commercial building was built in Nanjing, China. To quantify the energy-saving potential of the 3D-VtGW system, a thermal network model was developed to simulate the thermal behavior of buildings with 3D-VtGW system and for thermal comfort analysis. Whole-building energy simulation was carried out using Chinese Standard Weather Data (CSWD) o Nanjing, China. The simulation results indicate that the building with 3D-VtGW exhibited prominent potential for energy saving and improved thermal comfort. The integrated greenery system in 3D-VtGW largely reduces wall exterior surface temperature and through-wall heat flux via the combined effects of plant shading, evapotranspiration, and heat storage from soil. This study presents the immense opportunities brought by digital fabrication and construction to extend the design space and function integration in buildings.
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- Award ID(s):
- 1954517
- NSF-PAR ID:
- 10166328
- Date Published:
- Journal Name:
- Energy and buildings
- Volume:
- 222
- ISSN:
- 0378-7788
- Page Range / eLocation ID:
- 110110
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/https://doi.org/10.1016/j.enbuild.2020.110110
