Do I need a separate filter to control odors?
Because
almost all odors are connected with gases, even HEPA filters have almost
no ability to remove them from the air. The best solution to odor control
uses a combination of adsorption and oxidation.
In adsorption, most commonly using activated carbon, gas molecules wind
up attached to the surface of the collection medium. Think of each granule
of activated carbon as a golf ball with many microscopic dimples. The
gas molecules fit into the dimples and are held there by molecular forces.
The
effectiveness of the adsorption process is affected by the amount of
time that the stream takes to pass through the filter (residence time)
as well as the density of carbon. When all the dimples are filled, the
carbon is saturated and will begin to pass odors through and need replacement.
Therefore, the more carbon in the filter, the longer it will last.
Some odor causing molecules will not adhere readily to the surface of
the carbon. Fortunately, most of these molecules can be chemically transformed
by a process called oxidation in which oxygen is added to the gas. The
result is an air stream that no longer has odor problems. An oxidizer
like potassium permanganate will create this reaction without generating
ozone which can cause respiratory problems.
The combination of activated carbon and potassium permanganate in a
well engineered blend offers the ideal solution to odor problems in
an airstream. The NQ Commercial
Clarifier uses a cylindrical filter that includes 15 pounds of the
carbon/potassium permanganate blend with sufficient density and residence
time to provide a very effective odor removal system.
