Ventilation in New New Zealand Houses

In this presentation, we give an overview of ventilation in new New Zealand houses. At least 10% of New Zealand houses have a positive pressure mechanical ventilation system installed, generally pulling air from the roofspace cavity into the living spaces. We will discuss an in depth measurement and modelling study of two newer houses of timber frame construction with brick cladding and a corrugated iron roof that had positive pressure mechanical ventilation systems installed. The implications of moisture transfer from roofspaces into living spaces and of moisture condensation in houses with positive pressure mechanical ventilation systems will be discussed.