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Ultraviolet rays with wavelengths
shorter than 300 nm are extremely
effective in killing microorganisms.
The most effective sterilizing
range for UV is within the
C bandwidth (UVC). This range
is called the germicidal bandwidth.
UVC has been used in hospitals
for decades to sterilize surgical
instruments, water, and the
air in operating rooms. Many
food and drug companies use
germicidal lamps to disinfect
various types of products
and their containers.
The cleansing mechanism of
UV is a photochemical process.
The contaminants that pollute
the indoor environment are
almost entirely based upon
organic or carbon-based compounds.
These compounds breakdown
when exposed to high intensity
UV at 240 to 280 nm. Short-wave
ultraviolet light can destroy
DNA in living microorganisms
and breakdown organic material
found in indoor air. UVC’s
effectiveness is directly
related to intensity and exposure
time.
UV rays must strike the contaminants
directly in order to penetrate
the microorganism and breakdown
its molecular bonds. This
bond breakage translates into
cellular or genetic damage
with the germs rendered harmless
by robbing them of the ability
to reproduce.
Indoor Air Quality - IAQ,
UV And People's Health
According to the Environmental
Protection Agency (EPA), 10%
of all colds are caught outdoors,
90% are caught indoors! We’ve
all watched helplessly as
a cold virus passed from one
member of the family to another.
Perhaps you suffer from asthma
or allergies and despite desperate
attempts to dust more, keep
the windows closed, clean
your bedding, clothing, carpeting
and furniture more frequently,
your symptoms still persist.
The EPA states that indoor
air can be up to 70 times
more polluted than the outdoor
environment. One reason for
this is that the HVAC duct
work is full of airborne germs,
their particles and by products.
These microbes are alive and
thriving inside the furnace
or air conditioning systems.
The airborne germs adversely
affect the air quality as
they are blown past the furnace
or air conditioning filter
and circulated throughout
the buildings. in-duct and
upper air UV air cleaners
can be utilized to disinfect
the indoor air.
Most people take the quality
of indoor air for granted
and assume the air is clean
and safe to breathe. According
to the American Medical Association
50% of all illness is caused
or aggravated by polluted
indoor air.
The air in today's buildings
can contain different microbial
contaminants such as bacteria,
viruses, mold, fungi and spores.
Bioaerosols are the airborne
microbes, their fragments,
toxins and waste products.
Numerous studies have found
high concentrations of such
contaminants in the air handling
equipment and in the air inside
the places where people live
and work. These indoor air
pollutants can make the air
quality less than desirable,
may even cause unhealthy effects
ranging from allergies to
tuberculosis, and are actually
the cause of death to an estimated
8.5 million people annually.
Some studies state that properly
designed and installed UV
air cleaners will eradicate
or greatly reduce the microbial
contaminants from the indoor
air. This is why the indoor
air quality in public buildings
has been addressed by specific
requirements of UV installation
inside the HVAC systems.
When the problem of residential
indoor air quality became
apparent, ultraviolet technology
became the proven answer to
effectively controlling airborne
microbial pollutants. The
artificially generated UV
can reduce or virtually eliminate
all DNA based air pollutants
that regular filtering systems
do not catch.
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