reliability

It is estimated that more than 5000 householders in the UK have taken steps to reduce high radonlevels in their homes. In 1993 a number of homes with successful remedies installed were asked toparticipate in a study to determine the long term reliability of those systems. This involved the annualremeasurement of the radon concentration in each dwelling.

A number of differences between the experimental results and the calculated thermal behaviour results of the timber frame walls have been obtained during the investigation carried out at summer operation conditions. The aim of the recent investigation is to determine at what stage in the calculation procedure the most significant errors in the estimation of the values of physical parameters might be made. The impact of errors on the further calculation reliability will be discussed as well.

The problem developed and analyzed in this paper is that of the estimation of the uncertainty associated with the results obtained by numerical simulation codes of physical systems induced from input data. Implicitly posed by the authors is the delicate question concerning the use of the output obtained by calculation codes used in prediction situations, and the reliability which can be attributed to such ouput. One example of thermal behaviour of simple physical systems is treated, serving as an illustration.

Discusses what benefits there may be in employing an effective quality assurance program for building envelope air barrier systems, and what elements it should include. Proposes a protocol for inspection and testing of building envelope air barrier systems. Cites literature to highlight how testing has been shown to improve a building's air permeance.