Despatch LCC/LCD2-14-3 Non Pass Through Series - Manual (Page 26)

17
HEPA Filters
HEPA (High Efficiency Particulate Air) filters are used to limit particulate size in the work
chamber to 0.3 microns or less.
NOTE: Chamber temperature transitions must not exceed 1.25°C/minute in order to
maintain class 100 chamber conditions. An optional (Termikfil brand) filter is available
for transition rates up to 5°C/minute. Consult factory.
Definitions
HEPA - High Efficiency Particulate Air
Burn-Off - A process for getting rid of the binder contained in the filter.
D.O.P. - Dioctyl Phthalate - Aerosol particles of submicron size used in the testing
phase to spot defects or measure filter efficiency. Despatch Industries DOES NOT
RECOMMEND use of this or other organic challenge agents.
Binder - An organic substance that is used in the construction of the filter that gives
some structural strength to the media.
Filter Packaging and Shipping
Packaging practice varies among the filter unit manufacturers. Normally units are
packaged in cardboard cartons with various approaches for internal strengthening and
impact-resistance of the container. The shipping carton normally is marked with a
vertical arrow and "This Side Up". A filter unit is placed in the carton so that the pleated
folds are vertical (running from top to bottom - not side to side).
Filters should be shipped, handled and stored with the pleats in the vertical position. If
shipped with the pleats in the horizontal position, the filter medium may break at the
adhesive line. If handled or stored with the pleats in the horizontal position the pleats
may sag.
Moreover, the filter unit should be installed with the pleats in the vertical position. When
installed in the horizontal position the pleats form shelves for the collection of entrapped
material. The accumulated weight of this material causes sagging and leads to an early
failure of the unit.