Why UVC Germicidal Solutions

UVC Is Efficient and Safe

UVC Germicidal Fixtures increase the value of all air conditioning and air-circulating systems by:

  • Maximizing system efficiency
  • Prolonging blower life
  • Providing healthier air to breathe

Treating air that passes through an HVAC unit with ultraviolet light will reduce, or eliminate, DNA-based airborne contaminants (bacteria, viruses, mold spores, yeast, protozoa), and provide much healthier air to breathe. UVC Germicidal Fixtures are a labor-free solution that will not harm occupants, equipment or furnishings because they produce no ozone or secondary contaminants. For more than 70 years, tens of thousands have been safely installed in hospitals, clinics, processing plants, commercial offices, manufacturing sites and other commercial facilities and multi-and single-family residences around the world.

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Filters and Coil Cleaning

Filters are necessary to trap dust, pollen and other particles, however, to remove harmful bacteria and viruses from the air stream you need the addition of UVC light to render these microorganisms sterile, and therefore unable to reproduce.

Cleaning coils is like treating symptoms. Using UVC Germicidal Fixtures from American Ultraviolet Company, on the other hand, is actually more like curing the disease.

Without UVC, coils require constant cleaning, an expensive and inferior process that often relies on toxic and/or flammable solvents that are dangerous, and that can diminish the life of the coil. Cleaning also frequently leaves material embedded in the center of the fin pack. Steam cleaning, in particular, can actually force growth deeper into the fin pack, compressing it so tightly that the only solution could be to replace the coil.

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Financial Benefits

UVC Germicidal Fixtures keep coils clean all of the time, enabling HVAC systems to perform as originally intended, and ensuring:

  • System efficiency
  • Longer equipment life
  • Lower energy and maintenance costs

They'll often pay for themselves in months and can help you save many thousands of dollars in on-going energy and maintenance costs. In addition, UVC Germicidal Fixtures play a very important role in improving air quality and will eliminate the awful odor and slimy build up associated with mold and bacteria that thrive when temperatures are between 50-100F (especially when moisture is present), and that make air unhealthy for all building and residential occupants. Healthier employees mean better productivity and less sick time.

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Basics of UVC

For HVAC applications, just as with all other UVC sterilization applications, direct exposure to 254nm UVC radiation, given appropriate exposure time, will inactivate the DNA and RNA of microorganisms (such as bacteria, viruses, mold spores, yeast, and protozoa), rendering them "sterile" (unable to reproduce), which, in biological terms, results in a "dead" microorganism.

An acceptable kill rate is determined by the total amount of UVC energy a microorganism "sees." This is a "dosage." Dosage is a product of the intensity of UVC radiation (expressed in microwatts per square centimeter) and exposure time to that radiation. You can find the necessary dosage for most common mold spores in the following table. Mold spores are generally much more difficult to kill than microorganisms and viruses and, thus, require a much higher dosage of ultraviolet light. The values shown under the percentage kill are in microwatts per square centimeter of UVC energy.

MOLD SPORES Color 90% 90%
Aspergillius flavis Yellowish green 60,000 99,000
Aspergillius glaucus Bluish green 44,000 88,000
Aspergillius niger Black 132,000 330,000
Mucor racemosus A White gray 17,000 352,000
Mucor racemosus B White gray 17,000 352,000
Oospora lactis White 5,000 11,000
Penicillium expansum Olive 3,000 22,000
Penicillium roqueforti Green 13,000 26,400
Penicillium digitatum Olive 44,000 88,000
Rhisopus nigricans Black 111,000 220,000


Germicidal Lamp Technology

When researching UVC Germicidal Fixtures, you may come across several different types of lamp technologies and configurations.

All UVC lamps essentially consist of a quartz envelope containing mercury and other gases and electrodes. When the lamp is struck, the energy between the electrodes excites the mercury into a vapor, which produces C-band ultraviolet energy. Almost all germicidal lamps currently being used in mainstream HVAC applications have been low-pressure lamps; American Ultraviolet recommends using High Output lamps. Following is information about some of the more common UVC lamps:

  • Hot Cathode low-pressure lamps - this older technology, which is not very common today, uses a soft glass envelope (which devitrifies faster) and small electrodes (which put out less intensity and doesn't last as long as other lamps). They are rather inexpensive when compared to Slimline or High Output lamps.
  • Slimline low-pressure lamps- these have been the most commonly used germicidal ultraviolet lamps. They utilize a much harder quartz envelope and bigger electrodes than hot cathode lamps. They can have a useful life of up to 15,000 hours and produce almost two times the intensity of a hot cathode lamp of the same size.
  • High-output lamps- essentially Slimline lamps, these high-output lamps use a heavy-duty electrode and slightly different gas mixture to produce 100% more UV intensity than an equal length Slimline lamp, while still maintaining an effective life of up to 15,000 hours. The majority of American Ultraviolet UVC Germicidal Fixtures for HVAC applications use an even more efficient High Output ultraviolet lamp, and have an effective life of up to 17,000 hours (two years)

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Benefits of High Output Lamps

HVAC environments often involve low-temperature, high-velocity airflows. Standard Slimline, low-pressure, mercury arc, germicidal lamps are often over-cooled by these conditions. When the lamp is over-cooled, the result is reduced lamp intensity and less UVC output. High-output lamps operate at twice the current, which makes them less susceptible to over-cooling. In addition, HO lamps have a different gas mixture, which enhances the UVC output. HO lamps are specifically designed to operate in HVAC type environments.

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American Ultraviolet High Output Lamps

American Ultraviolet Germicidal Fixtures feature the highest High Output (HO) Lamps, which provide even greater efficiency than lamps other companies offer. And these lamps don't lose as much germicidal energy when temperatures fall within the HVAC system, enabling them to kill more mold and bacteria across a wider temperature and air velocity range than all others.

UVC Germicidal Fixtures from American Ultraviolet also:

  • Resist moisture, which prevents corrosion on lamp ends and electrical connections that can shorten lamp life (our fixtures actually outlive the lamps)
  • Feature patent pending lamps that are the easiest to install and replace
  • Contain lamps that offer a two-year guarantee (17,000 hours) of operation with only 20% decrease in output over the two years
  • Offer "Green" lamps that contain ≤ 8mg of mercury
  • Are made, assembled and tested in the USA
  • Can be used in unique custom in-duct and coil installations, for example, when very high volume airflow situations exist
  • Can be ordered with indicator lamps that notify customers when the lamp life has expired
  • Are very easy to maintain - simply wipe down with a damp cloth when performing already scheduled filter cleaning - no additional maintenance is necessary

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