Environmental Engineering Reference
In-Depth Information
Effect of dust spot filter efficiency and recirculation rate on tobacco
particle concentration. (From McNall, P.E.,
Figure 12.13
Arch. Environ. Health
, 30, 552, 1975. With
permission.)
Performance of an in-duct electronic air cleaner in a residence during a
period of smoking can be seen in Figure 12.14 . Smoke particle concentration
decreased by about 70% in 2 hours to reach a steady-state concentration as
occupant smoking continued. It decreased by an order of magnitude after
smoking ceased. Other studies with in-duct electronic air cleaners in resi-
dences have demonstrated an order of magnitude or more reduction of
airborne particles in unoccupied spaces. However, particle concentrations
decreased by only 40 to 60% when studied over extended periods of time
with unrestricted occupant activity. Occupant activities significantly reduced
the apparent performance of filtration units by affecting particle generation
and resuspension rates.
2.
Air cleaning to control particulate-phase biological contaminants
Air cleaners are used in hospitals to limit infections among surgical and
immunocompromised patients. Bacterial contamination of air in operating
rooms is a major concern because of the significant potential for postoperative
infections. The major cause of such infections is
Staphylococcus aureus
shed by
 
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