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UltraViolet [UV] Light in Massive Amounts Can Kill
Mold Growth and Mold Spores
Q.
How effective are the UV germicidal lights you can buy for your heating
and air conditioning system and as room lights at killing molds/ bacteria
in home. I have heard that UV lamps are used in hospitals to kill germs.
Is there solid research on the benefits or is this mostly a sales
gimmick? [March 13, 2005]
A.
One ultraviolet [UV] lamp of at least 10,000 uwats per second of exposure
can kill almost all biological contaminants in the air EXCEPT for mold,
which can take as high as 330,000 uwats per second of exposure, especially
for the dangerous and commonly-found indoor mold Aspergillus Niger. To
effectively kill mold with UV inside a heating/air conditioning system,
you would need to have your heating/cooling contractor construct in the
return air duct a kill box containing mirror-like surfaces to get a
multiplication of killing power through the bouncing effect of the rays
off the mirrors. The kill box would need at least a dozen or more UV
lights with a power of at least 20,000 uwats each. That many lights, plus
the bounce factor off the mirrors, would be strong enough in killing. In
addition, you would need to have an access panel into the kill box to
frequently dust off the bulbs which will become dust-laden and thus lose
their effectiveness unless you have a really effectively and frequently
replaced hepa filter system to clean incoming air into the return air
duct. Just as effective as a UV killing box [and much easier and less
expensive to install and maintain] would be to install a mass media [e.g.,
4 to 6 inches thick] hepa filter in the return air duct. Get a mass media
filter that can be washed, rather than replaced. Use an inexpensive,
disposable pre-filter to do initial dirt and mold removal prior to the air
entering the expensive mass media hepa filter. In addition to the mass
media filter, you could also install an electronic air cleaner into your
return air duct. If you install an electronic air cleaner and/or mass
media filter, you may need to upgrade the size of your ventilating fan and
motor to overcome the greater resistance to airflow caused by the air
cleaner and/or mass media filter. Alternatively, learn the 25 steps for
safe and effective mold
remediation. |