  This paper deals with the thermal performances of roof-mounted radiant
barriers. Using dynamic simulations of a mathematical model of a whole test
cell including a radiant barrier installed between the roof top and the
ceiling, the thermal performance of the roof is calculated. The mean method is
more particularly used to assess the thermal resistance of the building
component and lead to a value which is compared to the one obtained for a mass
insulation product such as polyurethane foam. On a further stage, the thermal
mathematical model is replaced by a thermo-aeraulic model which is used to
evaluate the thermal resistance of the roof as a function of the airflow rate.
The results shows a better performance of the roof in this new configuration,
which is widely used in practice. Finally, the mathematical relation between
the thermal resistance and the airflow rate is proposed.
