Unless you have the need and capacity to maintain a *clean room*
environment (i.e., certain computer centers, computer chip manufacturing
facilities, etc.) a HEPA filter should be more than adequate.
If people and ventilation ducts enter the *clean* space it will no longer
be clean. Mold spores are always with us; control is largely a matter of
maintaining temperature and relative humidity below their activation level.
The standard recommendation of approx. 70 degrees F and 50% RH is
adequate in most situations.
Jack C. Thompson
Thompson Conservation Lab
Portland, OR
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