Indoor Air: High Concentrations of Biological Contaminants
With tighter building construction in recent years, the quality of indoor air has declined dramatically.
The air circulating in the ductwork of the average home or office can be concentrated with contaminants including molds, bacteria, viruses, and dust mites. We fill our lungs up to 20,000 times each day. Over time, these contaminants can cause inflammation of the mucous membranes, upper respiratory problems, asthmatic conditions, headaches, and flu-like symptoms.
Filtering systems offer little or no help because these airborne contaminants either pass through the filter or simply collect on the filter medium, creating a breeding ground. Now, with the UV-Aire, Air Purifying System, a solution is available to directly address the problems associated with poor indoor air quality.
Facts About Indoor Air
According to the Environmental Protection Agency, the air in homes can be up to 100 times more polluted than outdoor air.1
The National Academy of Sciences Institute of Medicine reports that exposure to indoor pollutants is a key contributor to the asthma problems of this nation.2
Most allergy and asthma sources are passed from person to person through the air.
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.
Health effects may show up immediately, or after years of exposure to poor indoor air quality. These symptoms include some respiratory diseases, heart disease, and cancer. They may be severely debilitating or fatal.3
Facts About UV
The disinfection of medical equipment using UV has been a common and reliable practice.4
UV disinfection has been determined to be adequate for inactivating bacteria and viruses.5
The germicidal effects of UV light cause photochemical damage to DNA and RNA within microorganisms.6
“...ultraviolet radiation, properly integrated with heating, ventilating, and air conditioning systems, shows the most promise as a widely applicable means of air disinfection.” Richard Riley, M.D.7
* The UV-V wavelength generates ozone. According to the Environmental Protection Agency, ozone can be harmful to your health. When inhaled, ozone can damage the lungs. Relatively low amounts of ozone can cause chest pain, coughing, shortness of breath, and throat irritation. Ozone can also compromise your ability to fight respiratory infections. All UV-Aire lamps are coated to block this wavelength.
1. http://www.epa.gov/iaq/ - 5/16/01 2. http://www.epa.gov/iaq/asthma/intro/index.html#WhoGetsAsthma? - 5/16/01 3. http://www.epa.gov/iaq/ia-intro.html 4. “UVGI Design Basics” HPAC. January 2000. 5. EPA Guidance Manual Alternative Disinfectants and Oxidants. April 1999. 6. Jagger, J. 1967. Introduction to Research in Ultraviolet Photobiology. Prentice-Hall, Inc., Englewood Cliffs, NJ 7. Richard Riley, M.D. “Airborne Infection” The American Journal of Medicine, September 1974, Vol. 57
UV-AIRE® Air Purification System
How The In-duct UV-Aire Works
UV-Aire uses the energy from a specially designed, high-intensity UV-C lamp to reduce microorganisms in the entire home as they cycle through the HVAC system. Mounted inside the ductwork, the UV-Aire sterilizes or kills most contaminants as they pass the lamp.
The process requires very little maintenance and costs just pennies a day to operate. The UV-Aire could be one of the best health and comfort investments a homeowner ever makes.
Indoor Air Treatment With UV
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 40-75 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-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 safe, silent, and proven.
Since direct exposure to UV light can cause skin cancer and blindness, the most practical application of UV light in the home or office is in the main air distribution (heating and/or air conditioning) system. As UV light will not pass through metal, glass, or plastic, a UV light can be installed in the main supply or return duct of a central heating or air system without concern for direct exposure to eyes or skin. This is an ideal location since the air in the home or office will pass through the HVAC system up to 75 times per day during normal operation, and as many as 150 times per day in continuous fan mode.
Filter Systems Alone Don't Solve the Problem
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 through the porous filter. New, high efficiency style filters will only capture airborne bacteria down to a certain size. These high efficiency filters are nominally effective, trapping small airborne contaminants 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-coil. The buildup of matter on the A-coil and filter can significantly reduce the efficiency of the appliance by constricting and reducing air flow. This means increased cost to the homeowner in addition to the risk of airborne pollutants.
UV-AIRE® Air Purification System
How Much UV Energy is Required to Kill 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
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 a single UV-Aire lamp in an 18-inch square duct is 2,608 µW-sec/cm2 and 6,186 µW-sec/cm2 for 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.
The Bird Flu, Swine Flu Virus - H1N1, 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.
UV dose required for the de-activation of various microbes
Bacteria
UV Dose
Serratia Marcescens
6,160
Legionnella bozemanii
3,500
Legionnella micdadei
3,100
Mycobacterium tuberculosis
10,000
Salmonella enteritidis
7,600
Salmonella typhi (Typhoid Fever)
7,000
Streptococcus hemolyticus
5,500
Virus
UV Dose
Influenza
6,600
Infectious Hepatitis
8,000
Adeno Virus Type III
4,500
Rotavirus
24,000
Mold
UV Dose
Aspergillus amstelodami
77,000
Mucor Mucedo
77,000
Penicillium chrysogenum
56,000
Yeast
UV Dose
Baker's Yeast
8,000
Brewer's Yeast
13,200
UV dose is measured in microwatt seconds per centimeter squared (µW-sec/cm2). The information presented is intended to give the reader a general idea of how UV disinfects, based upon various credible resources. We do not guarantee its accuracy in any way.
Distance from Lamp
Intensity Factor
0
354
1"
127
2"
69
4"
32
6"
20
8"
14
10"
14
15"
6
20"
4
25"
3
30"
2
35"
1.4
39.97"
1
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.
Correlating The Lab Test With Other Bacteria
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/cm2 of UV energy versus 6,600 µW-sec/cm2 for 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
UV-AIRE® Air Purification System
STANDARD MODELS UV-12, UV-18, UV-28, UV-12HP, UV-18HP, UV-28HP
Hinged cover for easy accessibility
Includes patent pending angle bracket and duct board mounting kit
Installs easily and plugs into a standard 120V outlet
All UV-HP (heatpump) models are 240V
DUAL LAMP MODEL UV-18X
Double lamp maximizes intensity and effectiveness
Handles up to 4000 sq. ft.
Includes patent pending angle bracket and duct board mounting kit
Installs easily and plugs into a standard 120V outlet
Built-In Safety Switch Designed to light only inside the duct
E-Z Lamp Replacement Simple twist and lock
24 VOLT MODEL UV-16/24
24V Plug-in Transformer Included No electrician required
Compact Design Fits in tight spaces
Built-In Safety Switch Designed to light only inside the duct
E-Z Lamp Replacement Simple twist and lock
EXTERNAL MODELS UV-12E, UV-18E, UV-28E
For outdoor installations
Ideal for any external package systems
For rooftop applications
Hard wired for 120V, 208V, or 240V
UV-500C PORTABLE MODEL
Uses UV germicidal light, carbon, and high efficiency filtration
Quiet fan with three speed control
Purifies air in areas up to 500 square feet
Circuit board monitors lamp and filter life
Visual lamp and filter replacement alerts
Plugs into any standard 120V outlet
UV-1500C PORTABLE/WALL/CEILING MODEL
Purifies air in areas up to 1500 square feet
Sits on the floor, hangs on the wall, or installs in drop ceiling
Built-in fan with adjustable speed control
Circuit board technology monitors lamp life
Audible and visual lamp replacement alerts
Plugs into any standard 120V outlet
Uses UV germicidal light, carbon, and high efficiency filtration
Models & Specifications
Model
Minimum Duct Width
Voltage
Amps
Hz
Watts
Circuit Board
Recommended Max. Sq. Ft.
Lamp Intensity at 1 meter µW/cm2
Product Warranty
UV-12
9
120
0.5
60
30
no
1500
37
5 yr
UV-18
14
120
0.5
60
30
no
2000
73
5 yr
UV-28
22
120
1.1
60
60
no
3000
105
5 yr
UV-12E**
9
120/208/240
0.5
60
30
no
1500
37
5 yr
UV-18E**
14
120/208/240
0.5
60
30
no
2000
73
5 yr
UV-28E**
22
120/208/240
1.1
60
60
no
3000
105
5 yr
UV-12HP
9
240
0.5
60
30
no
1500
37
5 yr
UV-18HP
14
240
0.5
60
30
no
2000
73
5 yr
UV-28HP
22
240
1.1
60
60
no
3000
105
5 yr
UV-12C
9
120
0.5
60
30
yes
1500
37
1 yr
UV-18C
14
120
0.5
60
30
yes
2000
73
1 yr
UV-28C
22
120
1.1
60
60
yes
3000
105
1 yr
UV-12HPC
9
240
0.5
60
30
yes
1500
37
1 yr
UV-18HPC
14
240
0.5
60
30
yes
2000
73
1 yr
UV-28HPC
22
240
1.1
60
60
yes
3000
105
1 yr
UV-18X*
14
120
1.0
60
60
no
4000
2@73
5 yr
UV-500C
NA
120
0.4
60
36
yes
500
24
1 yr
UV-1500C
NA
120
0.5
60
30
yes
1500
37
1 yr
UV-16/120
16
120
0.5
60
30
no
2000
62
5 yr
UV-16/24
16
24
1.3
60
30
no
2000
62
5 yr
EL-1***
Fits any crawl space vent
120
0.6
60
35
-
1000
-
1 yr
EDH-1***
Humidity Switch
@120
12 max
-
-
-
-
-
1 yr
*UV-18X includes two lamps. **UV-E series includes aluminum NEMA 3 enclosures for external, outdoor installation. ***The EL-1 Eliminator and the EDH-1 De-Humidistat are not UV-Aire products but are recommended to help control and reduce moisture and moisture related problems in crawl spaces.
Note: All lamps are warranted for 90 days after installation. A UV-Aire counter display is available. For more information, contact Field Controls.
