We discussed about the various agents in play that determine the nature of IAQ and its negative impact on the building occupants, in case of high concentrations levels. We also discussed about the available solutions and mechanism that can be employed to address each of these major IAQ contaminants. When we are addressing IAQ problem in an existing building in any part of the world, we need to take note of the specific factors that might be effecting the IAQ of the building. Apprehending the indoor environment in its entirety involves taking into account all of the variables potentially affecting the indoor parameters, including the prevailing and future outdoor conditions. IAQ determining factors that will varies with different condition are:
- Geography: For e.g., the pollution problem would be different from buildings in landlocked areas to buildings in coastal areas or river-sides
- Climatic Conditions: For e.g., a building in a tropical zone would be effected more by mould growth and microbial pollutants than a building in the desert region. Again, an indoor fireplace can generate smoke or soot in colder regions which would not be a case in hotter climatic region
- Economy: Developing countries and under-developed countries are reeling under high air pollution level, due to less-stringent laws curbing emissions, high population rate, low cost life.
- Building Characteristics – types of the building foundation, the presence or absence of ventilation, tight or loose building envelope.
- Occupants’ Behavior: Ventilation habits – if windows are used instead of mechanical vents, indoor smoking, and choice and use of cleaning products
- Building Maintenance: It has been estimated that in 75 percent of IAQ problems arises from maintenance deficiencies. Maintenance problems related to building structure, HVAC systems, general housekeeping, and the lack of a comprehensive maintenance plan have all been identified as causes of poor IAQ.
Hence to manage the IAQ in existing buildings (retrofit) or the buildings that are still on the blue-print stage, the above factors will help in determining the nature of the problem and the best solution that can be employed.
However, as most buildings today are following specific standards worldwide and as air pollution is more or less rampant in the busiest cities around the world, there can be a comprehensive method to look into the IAQ problem that can be universal for all buildings. To analyze the IAQ problem of any building the following approaches can be adopted:
- Screening for airborne mould.
- Surface qualitative and quantitative testing for mould.
- Characterization of ventilation systems using environmental parameters – temperature, relative humidity, and dew point.
- Measurement of outside air volume and distribution.
- Surface or airborne dust characterization
- Screening of combustion by-product
- Testing for volatile organic compounds (TVOC).
- Quantification of allergens including dust mites, roach, pet danger.
