Controllable background ventilation in dwellings - The equivalent opening area needed to achieve appropriate indoor air quality

In dwellings there is a desire to reduce ventilation heat loss, by reducing uncontrollable air infiltration, at the same time as providing adequate indoor air quality by controllable background ventilation. In England and Wales, the background ventilation requirements in part F of the Building Regulations at present are expressed in prescriptive terms. The adopted European Standard, EN13141-1:2004, provides a means of assessing the performance of background ventilation devices, such as trickle ventilators, and gives a standard method of measuring the equivalent area of the ventilator.