Building Envelopes

The aim of this project is to develop the basis for a new active multi-functional building envelope that will provide the Swedish building industry with solutions using less materials and better functions. The development of thin novel insulating materials and the smart design of building envelope components are important aims.

The building envelope represents the interface separating the indoor and outdoor environment. New materials and technologies can be incorporated as building envelope components for new and adaptive features. Environmental concerns are in this context heat, air, water/moisture, gas, sound and light. Aerogel is a highly efficient thermal insulation material that can be used in order to reduce heat transfer through the building envelope (Schulz et al 2005, Baetens et al 2010). It is thought that the reduction in thickness of insulation compared to traditional materials could be as much as 8 times, although this requires a vacuum and carbon-black. Aerogel without vacuum or woven alternatives that might find use in retrofit. Various designs of the building envelope with thin insulators will be studied experimentally and with the use of simulation tools for whole building performance analysis under different climatic conditions. There are weak spots that need to be investigated coupled to junctions between building components, air tightness, durability, robustness and maintenance issues.

Through the smart design of building envelope components the changes in the exterior environmental conditions can be used to beneficially modify the indoor environment. One approach is the use of materials with non-linear characteristics to provide diode effects; another is controlled ventilation for energy efficiency and moisture safety (Hagentoft et al 2008). Research on material properties is performed through computer simulations for heat/moisture transfer and gas flow, accounting for materials structure, non-linear and anisotropic behavior. The simulations are verified experimentally. Based on the material characteristics, various design solutions for the building envelope are investigated with the use of simulation tools for the whole building performance and component analysis for different climatic conditions and building use.

 

More information:

Carl-Eric Hagentoft
Building Physics
carl-eric.hagentoft@chalmers.se

Building Envelopes have participated in the project Annex 23, Applying Energy Storage in Ultra-low Energy Buildings. More information and the final report can be found here: http://www.iea-eces.org/annexes/completed-annexes.html