Extract airExhaust valves are mounted in the moisture-generating rooms and strategically placed where they canextract the moisture air most effectively.Moisture-generating rooms:• Bathroom• Toilet• Kitchen• Utility roomSupply airSupply air valves are mounted in habitable rooms and strategically positioned to give the minimumannoyance. For example, it is not recommended to mount incoming air valves over areas where peoplesit, as the air in some cases can be perceived as a draught.Habitable rooms:• Living room• Kitchen-living room• Bedroom• OfficeRoof stackThe roof inlet and outlet must be positioned and designed to limit pressure fluctuations in theventilation system caused by wind impact, and also to prevent access by birds and other animals, andto ensure that the inlet and closed duct system are kept free of plant parts and foreign objects.The air inlet must be located to minimise the risk of short-circuiting from the discharge air, havingregard to the prevailing wind direction.The air inlet should be placed a minimum of 0.5 m above the roof surface, but a minimum of 1 m overflat black roofs up to the underside of the inlet, to ensure that warm air is not drawn into the building inthe summer. The air inlet should be located on the north or east sides of pitched roofs.Sound damping should also be mounted between the unit and roof stacks to avoid noise annoyance toneighbours.26