HOUSING
One of the main concerns in housing over the past two decades has been to build homes which are more energy efficient, thereby reducing heating costs, increasing occupant comfort and reducing the amount of pollutants released into the atmosphere by heating systems and power generation processes. This has been mainly achieved by increasing insulation levels, improved window technology, making the building shell more airtight and using more efficient heating systems.
In a number of cases the air quality in a house suffers because many designers, contractors, builders and homeowners do not understand the principles of building science and that the house acts as a system. While energy efficiency is very important and worthwhile, by only concentrating on this area of a house 'system', other areas, such as indoor air quality, have suffered.
As new houses are built more airtight and existing houses are being 'tightened up' in an effort to reduce energy costs, the natural air leakage in homes is no longer sufficient to reduce indoor air pollutants. Until fairly recently there was so much air leakage in and out of most houses that air pollutants were diluted and removed. Now, without that air leakage the pollutants can and often do build up inside the house to levels where they are damaging to human health. This doesn't mean that air leakage in houses should be allowed, but rather that other more efficient ventilation strategies must be used.
INDOOR AIR
As well as the reduction in air leakage in modern housing over the past few years, there has been a tremendous increase in the number of synthetic and composite materials used during the construction, renovation and refurnishing of houses. When used, many of these materials introduce new chemical pollutants into the home, and when combined with a lack of natural ventilation can mean that a multitude of different pollutants can reach concentrations where they become hazardous to the occupants health.
There are three basic methods with which to deal with the problem of poor indoor air quality:
- Eliminate the source of the pollutant (this may mean using alternative materials or sealing to prevent gases from entering the living spaces).
- Use of filtration systems to remove particles which may be inhaled from the air.
- Diluting the concentration of pollutants by the controlled introduction of fresh outside air, through the use of a balanced, mechanical ventilation system.
All three methods listed above are discussed in more detail later in this section, filtration and ventilation strategies are dealt with separately with the different available options outlined. The elimination of pollutants is dealt with as part of the individual descriptions of the various chemicals and materials that can contaminate indoor air.
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Information Technology Specialists Inc.