Energy usage for room heating, cooling and ventilation still accounts for more than one third of the total, primary energy demand in the industrialised countries, and is in this way a major polluter of the environment with CO2 and greenhouse-gases. To successfully achieve the targets set out in the Kyoto protocols it is necessary to identify innovative energy technologies and solutions for the medium and long term which facilitates the implementation and integration of low carbon technologies, such as renewable power generation devices within the built environment. Deployment of low carbon technologies still faces major barriers in the built environment especially in relation to costs, building logistics, technological challenges, lack of understanding and knowledge and absence of requisite skills. Moreover, there is world wide growing concern about the type of energy used for different purposes.
Research into building energy efficiency over the last decade has focused on efficiency improvements of specific building elements like the building envelope, including its walls, roofs and fenestration components (windows, daylighting, ventilation, etc.) and building equipment such as heating, ventilation, air handling, cooling equipment and lighting. In the framework of IEA research in ECBCS Annexes has focused on:
the optimisation of the building envelope - Annex 32 "Integral Building Envelope Performance Assessment"the optimisation of ventilation by intelligent hybrid ventilation - Annex 35 "Control Strategies for Hybrid Ventilation in New and Retrofitted Office Buildings (HybVent)"the optimisation of the heating and cooling system by low temperature heating and high temperature cooling - Annex 37 "Low Exergy Systems for Heating and Cooling"
Significant improvements have been made, and whilst most building elements still offer opportunities for efficiency improvements, the greatest future potential lies with technologies that promote the integration of active building elements and communication among building services. In this perspective Whole Building Concepts are defined as solutions where reactive building elements together with service functions are integrated into one system to reach an optimal environmental performance in terms of energy performance, resource consumption, ecological loadings and indoor environmental quality. Reactive Building Elements are defined as building construction elements which are actively used for transfer of heat, light, water and air. This means that construction elements (like floors, walls, roofs, foundation etc.) are logically and rationally combined and integrated with building service functions such as heating, cooling, ventilation and energy storage. The development, application and implementation of reactive building elements are considered to be a necessary step towards further energy efficiency improvements in the built environment.
With the integration of reactive building elements and building services, building design completely changes from design of individual systems to integrated design of "whole building concepts, augmented by "intelligent" systems and equipment. Development of enabling technologies such as sensors, controls and information systems are needed to allow the integration. Design strategies should allow for optimal use of natural energy strategies (daylighting, natural ventilation, passive cooling, etc.) as well as integration of renewable energy devices.
The annex will, based on the knowledge gained in the work so far (particularly the results of IEA Annexes 32, 35 and 37, SHC Task 23), address the following objectives:
Define state-of-the-art of reactive building elementsImprove and optimise reactive building elements and technologiesDevelop and optimise new building concepts with integration of reactive building elements, building services as well as natural and renewable energy strategiesDevelop tools for the early assessment of the impact of reactive building elements on the environmental performance of buildingsDevelop guidelines for procedures and tools for detailed simulation of environmental performance of reactive building elements and integrated building concepts
There are four areas of research:
Reactive Building Elements
Integration in Building Concepts
Design Tools and Environments Performance Assessment