Fluctuating airflow thorough buildings is caused by temporal and spatial variations of wind-induced pressures around building envelopes, and include pulsating airflow and eddy penetrations. Two approaches using a multi-zone pulsating airflow model are introduced in this paper to study the eddy penetration and multi-way airflow through large openings. In the first approach, the eddy flow is considered to be caused by imperfect correlations among pressures at different points of an opening.
Airtightness deficiencies of building envelopes and weaknesses in the ventilation systems can disrupt the operation of heating and ventilation systems. This can lead to an insufficient level of air quality and higher energy consumptions. In order to assess the performances of buildings and ventilation systems, CSTB has designed and developed different experimental devices for field testing. In a first step, an equipment was produced to measure the envelope air leakage. This apparatus is mainly used for research purposes.
In the field of insulation techniques, technical advances are mainly due to an interactive approach resulting from three complementary factors: * National building standards and government supported incentive programmes which aim to increase the thermal efficiency of residential and commercial buildings. * Research and Development programmes set up by manufacturers in order to lead to new or improved insulation materials or components with increasing R-values. * New construction techniques used by designers and builders to reduce heat loss through building envelopes.