摘要：Research indicates that many of symptoms attributed to the Sick Building Syndrome in air-conditioned office buildings are a result of considerably reduced negative ions in the internal atmosphere and that replacing the depleted negative ions can improve indoor air quality. This paper describes a method used to develop a formula (DOF-NIL formula) for calculating the amount of negative ions to be added to air-conditioned buildings, to improve air quality. The formula enables estimates to be made based on how negative ions in the air are reduced by three main factors namely, Video Display Terminals (VDT); heating, ventilation and air conditioning (HVAC) and Building Contents (BC). Calculations for a typical air-conditioned office, are compared with an Air Ion Counter instrument. The results show that the formula, when applied to a typical air-conditioned office, provides an accurate estimate for design purposes. The typical rate of additional negative-ions (ion-generating) for a negative ion condition is found to be approximately 12.0 billion ions/hr for at least 4 hour ion-generating.
