Where a PIV system is draughted from within the loft itself, it should be considered as ‘natural ventilation’, however, if the PIV is supplied directly from the outside, it would be considered as ‘mechanical ventilation - extract only’.
Where a PIV system is draughted from within the loft itself, it should be considered as ‘natural ventilation’, however, if the PIV is supplied directly from the outside, it would be considered as ‘mechanical ventilation - extract only’.