UV-AIRE®Air Purification System

UV Energy Required To Kill Bacteria

 

Correlating The Lab Test With Other Bacteria

 

 

 

Most, if not all bacteria can be destroyed by the use of UV light. The main factors in disinfection are the amount of UV power the lamp produces and the length of time the bacteria is exposed to the UV light source.

The energy required to kill microorganisms is a product of the UV light’s intensity and exposure time. This energy is measured in microwatt seconds per square centimeter.

Intensity x Exposure Time = microWatt seconds/cm2

Table 1 lists the amount of UV energy (measured in µW-sec/cm2) necessary to destroy various bacteria.

Independent lab testing of the UV-Aire shows that in a single-pass air flow test, one 18-inch UV-Aire lamp can reduce levels of Serratia Marcescens (a typical bacteria) by 93%, while a two lamp system can reduce by 99%.1

The calculated average UV energy output levels of

asingle UV-Aire lamp in an 18-inch square duct is 2,608 µW-sec/cm2 and 6,186 µW-sec/cm2for a two lamp system. The 6,186 is comparable to the 99% energy required for Serratia Marcescens. It can be seen that there is a direct correlation between the UV-Aire UV lamp output and the observed kill rates in the lab.

Lamp Intensity

Use the chart below to estimate the effectiveness of the UV-Aire with other bacteria.

Harder–to–kill bacteria and molds require greater energy or exposure time to be as effective. For example, 99% reduction of Rotavirus requires 24,000 µW-sec/cm2of UV energy versus 6,600 µW-sec/cm2for Influenza virus (see table below). This means that Rotavirus spores are five times more resistant than Influenza. Consequently, spores will require five times the UV output energy from the lamp or five times greater exposure time. For practical purposes, we recommend trapping the spores in a high efficiency filter downstream of the UV-Aire which can be irradiated continuously with the UV-Aire lamp.

For details of the lab test ask for form number 4291.

1.Efficiency of Bacterial Disinfection by a Duct-mounted UV-Aire®Air Purifier: by Microbe Management

Bird Flu Virus (Avian Flu)

The Bird Flu Virus is a type of Influenza. Since the kill rate for the influenza virus is 6,600 microwatts of UV energy, it is reasonable to conclude that the Bird Flu virus can be reduced or eliminated by 6,600-10,000 microwatts.

Distance

Intensity

Distance

Intensity

from Lamp

Factor

from Lamp

Factor

0

354

15"

6

1"

127

20"

4

2"

69

25"

3

4"

32

30"

2

6"

20

35"

1.4

8"

14

39.97"

1

10"

14

 

 

 

 

 

 

UV lamp intensity is rated at a distance of one meter. To determine the intensity of ultraviolet radiation at different distances from the lamp, multiply the intensity of the lamp by the intensity factor shown in the models and specifications chart.

Example: To determine the ultraviolet intensity of the UV-18 at a distance of six inches, multiply 73 by 20 to yield 1460 µW-sec/cm2.

UV dose required for the de-activation of various microbes

Bacteria

UV Dose

Mold

UV Dose

Serratia Marcescens

6,160

Aspergillus amstelodami

77,000

 

 

 

 

Legionnella bozemanii

3,500

Mucor Mucedo

77,000

 

 

 

 

Legionnella micdadei

3,100

Penicillium chrysogenum

56,000

 

 

 

 

Mycobacterium tuberculosis

10,000

Yeast

UV Dose

Salmonella enteritidis

7,600

Baker's Yeast

8,000

 

 

 

 

Salmonella typhi (Typhoid Fever)

7,000

Brewer's Yeast

13,200

 

 

 

 

Streptococcus hemolyticus

5,500

UV dose is measured in microwatt

 

 

 

 

Virus

UV Dose

seconds per centimeter squared

Adeno Virus Type III

4,500

(µW-sec/cm2). The information

presented is intended to give the reader

 

 

Infectious Hepatitis

8,000

a general idea of how UV disinfects,

 

 

based upon various credible resources.

Influenza

6,600

We do not guarantee its accuracy in

 

 

Rotavirus

24,000

any way.

 

 

 

 

 

 

 

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Field Controls 24v manual Lamp Intensity, Bird Flu Virus Avian Flu