Infiltration/exfiltration is the uncontrolled inward/outward leakage of outdoor/indoor air through air permeable materials, joints, cracks, interstices and other unintentional openings of a building envelope, caused by the pressure effects of wind, the stack effect or operation of HVAC-systems [1]. Infiltration/exfiltration causes convective … Continue reading →
Yes, provided that the building is equipped with an appropriate ventilation system (whether natural, mechanical or hybrid). A French study mentioned in the AIVC newsletter n°2 shows that better building airtightness converges with better indoor air quality because the ventilation system operates … Continue reading →
There are various kind of airtightness tester organizations. Some organizations are led by the qualification scheme in the country for example the British ATTMA and iATS and the Belgian BCCA. In France Qualibat is in charge of the qualification process … Continue reading →
The airtightness of a building is quantified by means of the measured air leakage rate through the building’s envelope in m³/h at a given reference pressure difference, often 50 Pa. The building airtightness may be expressed by other quantities, derived … Continue reading →
There are two major systems to classify ductwork airtightness, one based on European standards, the other one based on ASHRAE standard 90.1-2010. Both are based on the leakage airflow rate at a given ductwork pressure divided by the product of … Continue reading →
The relationship between the air flow rate (Q) and the pressure difference (ΔP) is often modeled by a power low: Q = C Pn The air flows from the higher to the lower pressure. For air to flow through the … Continue reading →
Air penetrates through porous building materials and through joints in the building structure, therefore, airtight construction techniques must focus on these aspects. Different construction materials exhibit different leakage characteristics. Irrespective of construction material, a modern building is normally of double skin construction in which … Continue reading →
Leakage in ventilation duct systems is important to keep to a minimum in order to save energy and keep the designed performance for a good indoor air quality. The tightness can be built by quality products and a professional installation or … Continue reading →
A combination of materials within wall and roof assemblies which establish a continuous plane of airtightness in the building envelope. Its most important function is moisture control, but it also plays a significant role in energy efficiency, rain control and external … Continue reading →
Requirements depend on the country and the context of the measurement. Most EU countries include in their regulations either required or recommended minimum airtightness levels with or without mandatory testing. There are several countries (e.g.United Kingdom, France, Belgium, Ireland) where, … Continue reading →
