The problem of optimal insulation thicknesses is one of the simplest that can be addressed by energy analysis. The authors begin with a simple analytical approach, and go on to describe detailed numerical work, based in the definition and parameterisation of a standard dwelling. Sensitivity of the results to large uncertainties in embodied energy data and building lifetime are investigated. The first conclusion is that insulation thicknesses in UK buildings are suboptimal in energy terms. This conclusion appears to be robust.
The paper is the second in a series of four which describe a three-year research project into advanced fabric-energy-storage (FES) systems. It presents the construction and validation of a computational-fluid-dynamics ( CFD) model of the 'FES-slab' which is subsequently used to investigate the slab's behaviour under a variety of boundary conditions and with modified air paths. Similar models are used to compare the FES-slab with the competing 'generic slab' and 'hollow-core screed' advanced FES systems.