Indoor Air Quality (IAQ) is quickly becoming a more noticed and
important problem in homes and businesses in the United States. IAQ has been
brought to the forefront in the HVAC (Heating, Ventilation, Air Conditioning)
industry recently as more people are complaining of problems with airborne
particles such as dust, pollen, pet dander, mold spores, fungi, bacteria,
viruses, smoke, cooking grease and humidity among others.
Over 90% of our time is spent indoors and 65% of that is at
home. The Environmental Protection Agency (EPA) calls Indoor Air Pollution: "One
of America's Five-Most-Serious environmental health risks." In addition, the EPA
states that the levels of some hazardous pollutants in indoor air had been found
to be up to 70 times greater than outdoor air. One out of six people who suffer
from allergies do so because of the direct relationship to fungi and bacteria in
the air duct systems. Biological contaminants in indoor air account for over 50%
of home allergies, according to the World Health Organization. Asthma and
allergy sufferers must endure constant bombardment by molds, dust, and spores.
Even worse, inhaling airborne bacteria and viruses can cause sicknesses ranging
from allergies to tuberculosis, and are actually the cause of death to an
estimated 8.5 million people annually.
There are several solutions available to help reduce these
problems associated with the HVAC system. No one solution alone will cure all
the problem but the following solutions used in conjunction with each other will
help to reduce IAQ problems.
Electronic Air Cleaners
Media Filters
UV Lights
Dehumidification
Chemical Treatments
Electronic Air
Cleaners (EAC) are effective at removing airborne particles such as
dust, pollen, pet dander, mold spores, fungi, bacteria, viruses, smoke, and
cooking grease. They also help to relieve allergy and asthma symptoms, prevent
damaging black dust from staining walls, upholstery and window coverings.
Unpleasant odors are controlled and HVAC equipment benefits with a prolonged
operating efficiency.
EAC's electronically remove up to 95% of the above airborne
particles down to .01 micron.
Your system should remove particulate materials from the air
being circulated throughout the building. Airborne particles range in size from
0.01 to 100 microns. Particles sized 10 microns or less are generally considered
to pose the greatest health hazard.
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Media Filters are
effective at removing airborne particles as small as .3 microns. Media filters
remove many of the indoor pollutants that would pass through a normal filter
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UV Lights
use the UV "C" band of ultraviolet rays that make up part of the suns light
spectrum. Scientists have known for years that the sun is one of natures most
effective air purifiers. UV-C light inhibits the growth and reproduction of
germs: Bacteria, viruses, fungi & mold just as the sun does outdoors with
ultraviolet rays. The air in a single room can contain hundreds of thousands of
infectious bacteria, viruses, fungal spores, and contaminants, which can only be
seen with a microscope.
Ultraviolet energy waves, invisible to the human eye, are lethal
to the microorganisms found in indoor air. To destroy microorganisms, UV rays
must strike the contaminants directly. UV light penetrates the microorganism and
breaks down molecular bonds causing cellular and/or genetic damage. The germs
are either killed or sterilized, leaving them unable to reproduce. In either
case, live bacterial counts can be significantly reduced and kept under control.
The majority of indoor air is conditioned by forced-air heating
and cooling (HVAC) systems. Standard fiber air filters are entirely ineffective
in trapping germs, as most particles are simply too small, passing right through
the porous filter. New, high efficiency filters will only capture airborne
bacteria down to a certain size. These high efficiency filters are nominally
effective, trapping small airborne contaminates on the filter, creating a
breeding ground where germs can continue to grow and multiply.
HVAC systems are a dark and damp breeding ground for mold and
bacteria, particularly at the system filter and air conditioning (A/C) coil. The
buildup of matter on the A/C coil and filter can significantly reduce the
efficiency of the appliance as the airflow is constricted and reduced. This
means increased cost to the homeowner on top of the risks of airborne
pollutants.
UV's effectiveness in killing bacteria is directly related to a
microorganism's exposure time. Indoor air in a typical residential forced-air
HVAC system will be recirculated over 50 times a day. With a UV generating lamp
mounted in the HVAC duct, cumulative exposure can be very effective in
controlling indoor bacteria. UV rays will also kill germs that breed in drain
pans and A/C coils. Properly positioned, an ultraviolet system can significantly
reduce indoor air contamination and prevent the growth of new microorganisms.
The treatment of indoor air with ultraviolet radiation has been
successful in health care facilities, food processing plants, schools,
laboratories and other applications. It is a safe, silent, and proven method of
improving indoor air quality.
Ultraviolet radiation by itself or in combination with a EAC or
high efficiency filter, is the most effective way to reduce airborne bacteria
and the health risks they represent.
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Dehumidification
The ASHRAE IAQ Standard indicates that relative humidity levels
should be maintained between 30 percent and 60 percent. Removal of high humidity
levels during the summer will help reduce mold growth inside the home and in the
ductwork where it is transported throughout the home. Dehumidification is
obtained through the use of a dehumidifier or a variable speed blower in the
furnace or air handler. Slower fan speeds increase the amount of humidity
absorbed by the cooling coil in the A/C system reducing humidity levels which in
turn, also make the air feel cooler allowing for a higher thermostat setting.
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Look for more interesting information on Indoor Air Quality coming soon.
