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Thermally activated building systems within building envelopes

The purpose of the work presented in this thesis is to investigate if an externally insulated cavity wall activated using a 'Thermally Activated Building System' (TABS) and linked to an environmental source can become an energy actuator~ balancing distribution within a building's thermal mass and reducing peaks in energy demand. Internal space conditioning is mainly responsible for high levels of energy consumption within most buildings. Many energy strategies strive to manipulate building physics and architectural design to exploit viable low energy heating and cooling systems that can maintain and balance envelope integrity and occupant thermal comfort. A common method of reducing energy consumption and improving performance is the application of external insulation to walls. This reduces dynamic transmission and creates a capacitive layer with the potential to provide a heat sink for environmentally generated heat and coolth for short-term usage. To exercise the distribution of heat from generation sources, TABS is embedded into the outer mass layer that is externally insulated. The large surface areas involved creates dynamic heat flows that positively influence structural integrity and the internal space. The ability to hydraulically circulate energy within this mass layer and other zones also provides reduced thermal elemental stratification and improved structural thermal equilibrium. This project used both steady-state and cyclical scientific methods to carry out experimental testing within a hot box calorimeter. Steady-state testing was completed and compared to calculated methods, validating the thermophysical properties of the wall. A parametric study using a hot box calorimeter was conducted (with and without TABS) across staged performance upgrades to the cavity wall and a comparative study completed based on the results. In this thesis, results from cyclical testing showed that elemental thickness and location was key to maximising the walls performance within winter and summer variations. The air-filled cavity wall with external insulation outperformed the full filled cavity with insulation (with and without activation), even though the full filled cavity wall had a lower U-value. A detailed analysis of thermal stratification in the vertical plane of the wall showed that increased thermal control was possible with an optimised wall configuration and thermal activation. The application of TABS increased thermal storage (heating and cooling) within the mass layers with redundancy to accommodate increased overall performance from the TABS and aggregated systems. The thesis concludes that overall the application of TABS to a cavity wall is an effective solution, increasing the performance potential of primary systems (heating and cooling) and reducing the effects of construction deficiencies.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:700825
Date January 2016
CreatorsCotter, Donal Fergal
PublisherUlster University
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation

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