Ventilation Introduction

• New building materials and construction methods are effectively resulting in "waterproof" buildings. They trap moisture inside just as effectively as they keep moisture out.
  

• Open doors and windows provide air circulation and ventilation but security considerations mean that we are increasingly less likely to use this option. Houses tend to remain closed up more and more.
  

• Poor ventilation results in a consistent buildup of moisture generated by cooking/bathing-showering/clothes washing-drying/LPG gas heating/etc.

Moisture Generators

Problems Caused by Poor Ventilation

• Stale air can be caused by cooking smells, odours remaining in the bathroom, a general lack of ventilation around the house as well as a damp atmosphere.
  

• All these problems cause an avoidable level of discomfort as well as the risk of respiratory illness and general poor health.
  

• Problems also occur when steam from the kitchen or bathroom finds cooler surfaces around the house on which to condense. Warm, moisture-laden air condenses on cold surfaces such as glass, cold ceilings and cold wetwall linings. This is the moisture that you can see.
  

• Moisture you cannot see is still present in the atmosphere and will be absorbed into fabrics, wall linings, bedding, etc. Attempts to conserve heat by sealing windows - and therefore reducing natural ventilation - makes this problem even worse.
  

• Condensation can cause considerable problems from peeling wallpaper and mould growth to severe long term structural damage to building materials.

In dwellings with a metal roof, or where the roof is lined with sarking, ventilating
directly into the roof space is not permitted under the Building Code.

Your Ventilation Solutions
Fan Regulations
How to Select a Fan
Calculating Fan Performance
What Affects Performance
Fan Applications