‘A wall is not a ventilation system, therefore airtightness is not the enemy.’
INFILTRATION IS NOT VENTILATIONHow are our houses being ventilated? The answer is “poorly”. There is an accidental reliance on infiltration through the building to provide some background air movement, but this is not fresh outdoor air as required by the building code (G4 Ventilation). Nor is it controllable — when it is windy there is a greater rate of air change per hour, but a few days of calm or in a sheltered environment and the percentage of CO2 in the air could be at ‘sleep inducing’ levels. Never mind the relative humidity inside the building.
Yet this is how the problems start. We want to be comfortable in our homes, insulated from the weather — including stopping drafts. By doing this we raise the requirement for intervention either by opening windows or by using a mechanical ventilation system …read more