Why UVC Germicidal Solutions

Essentials of Germicidal Irradiation for Reduction of Microorganisms

American Ultraviolet High Output Lamps

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
Disinfecting air and surfaces in the AHU

Treating air that passes through an HVAC unit with ultraviolet light will reduce, or eliminate, DNA and RNA-based airborne microorganisms. 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 60 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 a permanent solution.

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 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).

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Basics of UVC

For HVAC applications, just as with all other UVC disinfection applications, direct exposure to 254nm UVC radiation, given appropriate exposure time, will inactivate the DNA and RNA of microorganisms, rendering them unable to reproduce.

A lethal dose of UVC energy 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 target dosage for most common mold spores in the following table. Mold spores are generally much more difficult to inactivate 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%	99.9%
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

Essentials of Germicidal Irradiation for Reduction of Microorganisms

The first documented application of UV for the purpose of disinfection was a 1910 prototype drinking water plant in Marseille, France1. Since that time, effective use of ultraviolet energy for reduction of microorganisms has spread to a wide variety of applications including drinking and wastewater, indoor air quality, food safety, horticulture, healthcare, and consumer products. The list of current applications is far too long to fully list here, so the simplest summation is that UV-C technology is now widely used to effect reduction of bacteria, viruses, molds and other microorganisms in air and liquids and on surfaces. Read full article.

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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 inactivate 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 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
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