Commercial buildings require mechanical ventilating systems, the specifications for which are included in the building codes. These codes specify the amount of outdoor air to be supplied per person for designed occupancy conditions. Many buildings such as retail establishments operate much of the time at occupancy loads well below the design. Thus, they are generally over ventilated and waste energy when operated according to the codes. A control system based on measurement of the carbon dioxide generated by the occupants was tested in a small bank in Pasco, Washington.
Air qulaity measurements along with airflow rate measurements of air conditioning system were conducted in an office building occupied by workers with clerical activities. Contaminamts measured were CO2, SPM (suspended particulate matters) NOx and airborne bacteria. Indoor CO2 and SPM levels were found to be quite high, 1,600 ppm (CO2) and 0.25mg/ m3 (SPM), respectively, at their maximum and exceeded Japanese Standards The cause of the high concentration was found to be air leakage in the outdoor air intake duct. The air leakage rate was estimated applying mass-balance model of CO2.
Air pollution is not just a phenomenon associated with urbanization and industrialization. It is possible that the principal exposures to several important pollutants occur in rural areas of developing countries where the population relies on biomass fuels for their energy needs. These fuels have large emission factors for particulates, CO and a range of hydrocarbons. Rural studies have found very high BaP concentrations. Effects on health have not been researched, but can be assumed to be similar to urban occupational air pollution effects.
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