Most people spend up to 80% of their time indoors and are becoming increasingly aware of the importance of good Indoor Air Quality (IAQ).  Adequate ventilation must be provided in a building for the well being of its occupants.

Double glazing, cavity insulation and draught proofing have helped to prevent heat loss in modern buildings but at the same time they have sealed us off from natural fresh air.  Without adequate ventilation, these improvements in construction methods result in high levels of humidity and condensation and create a trap for indoor pollutants and contaminants.

It is virtually impossible to list all indoor pollutants and contaminants.  The following are the most common - carbon dioxide produced naturally by the occupants breath, body odours, cooking, pet and sanitation smells and other unpleasant odours, tobacco smoke, viruses, bacteria, mould and mildew, plant spores, pollen and the house dust mite.  Organic gases may be given off for long periods of time from volatile organic compounds such as cleaning and disinfecting agents, paints, varnishes, wood preservatives and carpets.

High humidity levels, condensation and mould growths, not only cause damage to internal decoration and the fabric of the building itself, but also constitutes a health risk to the occupants.

Humid conditions provide an ideal breeding ground for the house dust mite, which infests bedding, carpets and soft furnishings. This unwelcome creature is considered to be a primary cause of asthma and other allergies.

Energy is wasted as expensive heat is lost through the use of ordinary extractor fans and/or opening windows, defeating the purpose of double glazing and high levels of insulation.