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Purifying Air in Kennels and Veterinarian Centers

Illness among animals especially dogs can be significantly higher when many of them are boarded within close proximity, or kept within the same room or building. Airborne illnesses can easily be transmitted from one animal to another. Odors may cause issues when they migrate to other areas and affect staff and visitors.

Sanuvox UV systems are the ideal solution for destroying airborne viruses and bacteria, as well as reducing the concentration of unpleasant odors, such as ammonia produced by animals in kennels, shelters, pet stores and veterinarian clinics. Its proprietary system eradicates biological contaminants (bacteria, viruses, germs and allergens), and destroys chemicals and biological odors.

THE EQUIPMENT

Multiple application UV systems can be used for both stand-alone and duct-mount installations.

As stand-alone units, the P900 is equipped with an 80 cfm blower, the Sanuvair® S300 with a 300 cfm blower, and the Sanuvair® S1000 with a 1000 cfm blower. Sanuvair® S300 and S1000 also come with filters to capture particulates (pet hair, etc.). A dual zone UV-C/UV-V lamp is standard. An “adjustable” oxidizing lamp is available.

As an in-duct unit, the Quattro is installed parallel to the airflow and includes four UV-C/UV-V lamps, each with a one-inch section of oxidizing UV-V. Two of the lamp’s oxidizing sections are covered with removable foil, allowing for increased oxidation if necessary.

Typical installations:

OPERATING THE EQUIPMENT

Each unit treats the air through recirculation in two ways:
1. The Germicidal UV-C lamp portion destroys airborne biological contaminants (viruses, mold,
bacteria.)
2. The Oxidizing UV-V lamp portion reduces airborne chemical contaminants and VOCs through
photo-oxidation.

PROCESS ON BIOLOGICAL AND CHEMICAL CONTAMINANTS

1-ACTIVATION PHASE:  H2O + O* –> OH* +OH*
Ultraviolet photon energy (170-220nm) is emitted from a high-intensity source to decompose (break down) oxygen molecules into activated monoatomic oxygen. The rate of production or effectiveness of this process depends on the wavelength and intensity of its source.

2-REACTION PHASE: OH*+P –> POH
The activated oxygen atoms (O*) are then mixed in the airstream; the process will react with any compound containing carbon-hydrogen or sulfur, reducing them by successive oxidation to odorless and harmless by-products. If airborne contaminants are outnumbered by the activated oxygen atoms, then there will be formation of residual ozone (O3) which will occur following the oxidation of normal oxygen molecules (02).

3- NEUTRALISATION PHASE: (also germicidal)  O3+UV(C) –> O2+O*: O+O –> O2

CHEMICAL DECOMPOSITION:
Ammonia NH3+OH* –> N2 + H2O

WHERE TO INSTALL

Many buildings and facilities can be equipped with either the stand-alone disinfection units or the in-duct unit, like kennels, pet boarding and animal shelters, laboratories, veterinarian centers, and zoos and pet stores.

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Extending Shelf-life and Delivering Exceptional Quality

Mold and bacteria can severely impact the delicate payload on its way to storage facilities and retail stores. Ethylene off-gassing causes fruits and vegetables to prematurely ripen and age dramatically, shortening their shelf-life.

Sanuvox technologies offers an exceptional cost-effective mobile air treatment solution that easily incorporates into any truck or tailer designed to destroy airborne bio-chemical contaminants including bacteria, mold and ethylene off-gassing.

With its high efficiency patented air disinfection systems, Sanuvox offers the right solution when the objective is to destroy airborne contaminants, such as bacteria, viruses and mold that may affect the integrity of produce in transit. It also destroy ethylene, which causes produce to ripen faster.

THE EQUIPMENT

The 12V VP900 Interceptor is a small mobile air disinfection unit that can can be mounted in any location within the trailer or truck to sterilize airborne contamination and destroy ethylene gas. The UV system runs continuously bringing down contamination levels on an ongoing basis.

VP900 Interceptor:

OPERATING THE EQUIPMENT

The Interceptor recirculates the air, where:
1. The UV-C germicidal section of the UV lamp destroys airborne biological contaminants (viruses, mold, bacteria and spores).
2. The UV-V oxidizing section of the UV lamp reduces ethylene, slowing down the ripening process of vegetables and fruits.

SLOWING DOWN THE CONTAMINATION SPREAD WITH UV-C
Produce will degrade due to the rotting process. Rotting is caused by parasitic fungi and mold. Food deterioration begins with the breakdown of the cellular tissue by enzymatic action that allows the growth of microbes. Germicidal UV (UV-C) is extremely effective at preventing the reproduction of bio-contaminants. UV-C destroys airborne fungi, molds and their spores, limiting the contamination spread from one fruit to another. Meat, fish and chicken are especially vulnerable to airborne biocontamination. UV-C sterilizes the air, destroying contaminants as they circulate within the cold room.

RETARDING THE RIPENING PROCESS WITH UV-V
Photo-oxidation with UV-V can be used to reduce chemicals that trigger the ripening of fruits and vegetables. The life stages of a plant are influenced by plant hormones. An organic compound involved with ripening is ethylene, a gas created by plants from the amino acid, methionine. Ethylene increases the intracellular levels of certain enzymes in fruit and fresh-cut products, which include:

  • Amylase, which hydrolyzes starch to produce simple sugars.
  • Pectinase, which hydrolyzes pectin, a substance that keeps fruit hard.

UV-V oxidizes and thus neutralizes the ethylene molecules released by the ripening process, slowing down the spread of ripening to the surrounding produce.
This oxidation process breaks down ethylene into carbon dioxide and water vapor.
Ethylene C2H4 C2H4 + O* CO2 +H2O

WHERE TO INSTALL

The VP900 Interceptor can be installed in many places, like trucks transporting fruits and vegetables, cold storage rooms, groceries, fruit and vegetable retailers, or warehousing.

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Removing Ground Level Odors

Processing activities, as well as maintenance operations, can produce troublesome odors that may affect those working and visiting a site or facility. It may even cause problems for those living in the underline community. These applications include sewage treatment facilities, sump pump operations, excavation, pumping stations, arena ice pits, grease traps, etc.

Sanuvox UV disinfection systems may be outfitted with special oxidation UV Lamp (185nm) that produce high levels of ozone (O3) to effectively combat odors emanating from these various types of applications. The self-contained systems can be located very close to the source of the odor alleviating the issue where it is most concentrated.

When the objective is to to substantially reduce odors generated by a sump pit, such as sewage ditch, sewer pumping stations, residual from ice scraping equipment (Zamboni), or grease traps, Sanuvox offers the right solution with its high efficiency patented air disinfection system.

THE EQUIPMENT

Stand-alone units that will either process air through recirculation in a room or inject a small quantity of ozone directly into the specific containment device to reduce odors.

An ozone controller can be used to limit the residual ozone outside of the containment area to a concentration level lower than the ASHRAE limit (0.05ppm).

Typical Sanuvair® S1000 OZD INSTALLATION:

OPERATING THE EQUIPMENT

The unit purifies the air through recirculation in two ways:
1. The UV lamp germicidal section destroys biological contaminants (viruses, fungi, bacteria) moving through air.
2. The UV lamp oxidizing section reduces the chemical components in the air through photo-oxidation.

PROCESS ON BIOLOGICAL AND CHEMICAL CONTAMINANTS
1-ACTIVATION PHASE: H2O+ O* –> OH* +OH*
Ultraviolet photon energy (170-220nm) is emitted from a high-intensity source to decompose (break-down) oxygen molecules into activated monoatomic oxygen. The rate of production or effectiveness of this process depends on the wavelength and intensity of its source.

2-REACTION PHASE: OH*+P –> POH
The activated oxygen atoms (O*) are then mixed in the airstream; the process will react with any compound containing carbon-hydrogen or sulfur, reducing them by successive oxidation to odorless and harmless by-products. If the activated oxygen atoms outnumber airborne contaminants, there will be the formation of ozone (O3) which will occur following the oxidation of normal oxygen molecules (02).

3- NEUTRALISATION PHASE: (also germicidal) O3+UV(C) –> O2+O*: O+O –> O2

SIZING
The stand-alone units will include an extra oxidizing (UV-V) lamp. In the absence of an ozone controller, a warning label must be provided to the user. Certain conditions may require up to four UV-V lamps in one unit.

WHERE TO INSTALL

Many buildings and facilities can be equipped with the S1000, like municipal sewage treatment plants, municipal pumping stations, ice-snow containment (pit) areas, hotels grease pits, and grey water treatment.

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Fighting Tobacco Smoke

Designated smoking areas, althrough typically spared from working and living spaces, often cause problems with air that may very well circulate in and out of these areas. The smoking area itself may be overwhelmed with cigarette smoke, causing smokers to seek alternative places to smoke.

Sanuvox Technologies offers two units that are effective at removing tobacco smoke from the air and reducing cigarette odors, as well as nicotine and smoke that are so problematic. Unlike conventional technologies, Sanuvox UV systems do not use costly carbon for absorption nor rely solely on filters, which easily become coated with tar and nicotine The proprietory process changes the molecular structure of the tobacco smoke into a fine powder, which is then captured on the filter media. It is recommended that the UV systems be sized to provide a recirculation rate of 6 to 8 air changes per hour.

THE EQUIPMENT

Stand-alone Sanuvair® 300 VOC or Sanuvair® 1000 VOC UV air purifiers that include germicidal and oxidizing ultraviolet lamps, prefilters and a main filter to capture nicotine and smoke. An optional VOC (Volatile Organic Compound) detector can be used with multiple lamps when the number of occupants increases.

Typical installation:

OPERATING THE EQUIPMENT

Sanuvox dual zone UV lamp will reduce odors, nicotine and smoke in the room through recirculation. With the optional UV-V lamp(s) and VOC detector, if the smoke level increases (because there are more smokers), the VOC detector will trigger the additional oxidizing lamp(s), then shut them off when the level decreases. The cycle is repeated, lowering the odor, nicotine and smoke levels, until the maximum reduction is reached.

UNDERSTANDING THE CHEMISTRY
Cigarette smoke is composed mainly of:

  • White ash
  • Nicotine molecules
  • Chemical by-products

Ash will be trapped by the pre-filters. Nicotine will be transformed into a type of yellow powder that will be captured by the prefilters and the main filter. The chemical by-products will be oxidized by the UV process: high frequency UV-V energy activates the organic molecules and accelerates the chemical reaction, resulting in the air being oxidized. Odors are oxidized by the process of photolysis that initiates the breaking of chemical bonds by the action of the ultraviolet light. The oxidation process will reduce odors and chemical contaminants by changing the complex molecular contaminants into CO2 and H2O

SIZING THE EQUIPMENT

Approximately 6 to 8 air changes per hour are required. This reduces the standard of fresh air required by two thirds.

An Sanuvair® S300 VOC unit (300 cfm) will be sufficient for a 1,920 cu.ft. room (12’ X 20’ X 8’) with 9.3 changes per hour.

An Sanuvair® S1000 VOC unit (1000 cfm) will be sufficient for a 9,600 cu.ft. room (20’ X 40’ X 10’) with 7.5 changes per hour.

WHERE TO INSTALL

Many buildings and facilities can be equipped with one of these stand-alone units, like eldercare homes, private homes, poker rooms and casinos, bingo halls, cigar bar, or smoking rooms.

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Fruits and Vegetables Surface Disinfection

Surface contamination of fruits and vegetables is a problem for growers, distributors and retailers. Mold and bacteria can have severe effects causing produce to spoil.

Sanuvox UV IL Food Safe purifiers for food products and their packaging are exceptionally safe and versatile disinfection systems for surface, packaging and conveyor applications designed to bask meat, fish, poultry, fruits and vegetables, baked goods and packaging with UV-C germicidal light. The UV system is extremely effective at destroying surface contamination while extending product shelf-life. Only a few seconds of exposure can achieve up to 99.9999% destruction of common biological contaminants that are problematic in the food industry.

Incorporate the UV fixtures into the production line (i.e. over the conveyor belts) to bask the products and surfaces prior to packaging, maintening a sterile product ready for distribution and consumption.

As the system is incorporated into the production line, the lamps are covered with Teflon, that will trap pieces of grlass in the event of breakage.

When the objective is to prevent and destroy microbial contamination, such as bacteria and fungi that occur naturally on fruit and vegetable surfaces, and are responsible for premature decay, Sanuvox offers the right solution with its high efficiency patented air purification system. The process will leave no residue as is found using chlorine or irradiation treatments with gamma rays. At the producer level, sterilization of fruits and vegetables could reduce the use of pesticides.

THE EQUIPMENT

IL Food Safe purifier for food products equipped with parabolic reflectors and Teflon coated lamps will be positioned equidistant across the conveyor, parallel to it. Computerized sizing programs taking into account the speed of the conveyor and the contaminant(s) to be treated will determine the size of the lamps.

Typical installation:

 

OPERATING THE EQUIPMENT

The end user will determine the location and design of the lamp assembly enclosure that will attach to
the conveyor guaranteeing there is no direct UV exposure to employees. Fruits and/or vegetables will be exposed for a predetermined period of time to UV light as they move through the enclosure on the conveyor. This predetermined time will be sufficient to sterilize the fruit and/or vegetable pathogens and slow down ripening process.

RESEARCH ON STRAWBERRIES
Researchers from the Department of Food, Science and Nutrition (Laval University, Quebec, Canada) demonstrated that exposing strawberries to ultraviolet light prolongs their shelf life. Freshly picked strawberries exposed to germicidal ultraviolet (UV-C) have retained their freshness for 14 to 15 days, while untreated freshly picked strawberries were “almost done” on the tenth day.

The conclusions from this research have been published in the Food Science Journal. Refrigeration, which slows the growth of microorganisms and fruit ripening, allows a limited but effective mean regarding conservation of strawberries.

“Exposure to UV-C is a very interesting approach to facilitate the marketing and distribution of fresh fruits and vegetables”, says researcher Joseph Arul. This treatment slows the ripening of strawberries: they remain firm longer, their respiratory rate is lower, their color is more attractive and the taste is not altered. “It is believed that exposure to UV-C would kill some mold on the surface of the fruit or, more likely, the treatment would stimulate the defense mechanisms of the produce,” suggests the researcher.

Arul’s team has already demonstrated the benefits of UV-C exposure for the conservation of carrots, broccoli, tomatoes and blueberries.

Arul does not anticipate negative reactions from consumers, unlike gamma irradiated food, or more recently, genetically modified organisms. “The technique is more acceptable to a consumer. In low doses, UV is beneficial. It is a light source and I do not think people have problems with that.”

WHERE TO INSTALL

Many facilities can be equipped with the IL Food Safe, like vegetable growers, fruit and vegetable importers, hydroponic producers, and value-added packagers.

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Disinfecting Air and Reducing Ethylene in Cold Rooms

Mold and bacteria can severely impact the quality of meat, chicken, fish, fruits and vegetables that may be stored or prepared in warehouses and cold rooms. Ethylene off-gassing causes fruits and vegetables to prematurely ripen and aged, dramatically shortening shelf-life.

Sanuvox UV IL-CoilCean systems installed facing the cooling coil are designed to bask the coil and air with ultraviolet energy destroying microorganisms including bacteria, mold and viruses while oxidizing and reducing ethylene off-gassing.

With its high efficiency patented air disinfection systems, Sanuvox offers the right solution when the objective is to destroy airborne bio-chemical contaminants (e.g. bacteria, viruses, mold) that may affect the storage and preparation of fish, chicken and meat, as well as destroy ethylene off-gassing that causes produce to ripen faster.

THE EQUIPMENT

Multi-IL CoilClean units are installed facing the cooling coils in the fan coil unit. Each IL unit includes a UV-C/UV-V lamp mounted in an anodized aluminum parabolic reflector. The ballast box incorporates LED status lights for providing lamp status and replacement and can be remotely monitored.

OPERATING THE EQUIPMENT

The fan coil unit recirculates the air where:
1. The UV-C germicidal section of the UV lamp destroys airborne biological contaminants (viruses, mold, bacteria and spores).
2. The UV-V oxidizing section of the UV lamp reduces ethylene, slowing down the ripening process of vegetables and fruits. Coils remain clean and more energy efficient.

SLOWING DOWN THE CONTAMINATION SPREAD WITH UV-C

Produce will degrade due to the rotting process that is caused by parasitic fungi and mold. Food deterioration begins with the breakdown of the cellular tissue by enzymatic action that allows the growth of microbes. Germicidal UV (UV-C) is extremely effective at preventing the reproduction of bio-contaminants because UV-C destroys airborne fungi, molds and spores, limiting the contamination spread from one fruit to another. Meat, fish and chicken are especially vulnerable to airborne biocontamination. UV-C sterilizes the air, destroying contaminants as they circulate within the cold room.

RETARDING THE RIPENING PROCESS WITH UV-V

Photo-oxidation with UV-V can be used to reduce chemicals that trigger the ripening of fruits and vegetables. The life stages of a plant are influenced by plant hormones. An organic compound involved with ripening is ethylene, a gas created by plants from the amino acid, methionine. Ethylene increases the intracellular levels of certain enzymes in fruit and fresh-cut products, which include:

  • Amylase, which hydrolyzes starch to produce simple sugars.
  • Pectinase, which hydrolyzes pectin, a substance that keeps fruit hard.

UV-V oxidizes and thus neutralizes the ethylene molecules released by the ripening process, slowing down the spread of ripening to the surrounding produce. This oxidation process breaks down ethylene into carbon dioxide and water vapor.
Ethylene C2H4 C2H4+ O* -> CO2 +H2O

WHERE TO INSTALL

Many buildings and facilities can be equipped with the IL-CoilCean systems, like cold storage rooms, groceries, meat, fish and chicken storage, preparation facilities, fruit and vegetable retailers, warehousing and transportation.

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Formicary Corrosion and Biofilm Fouling of Cooling Coils

Air conditioning is responsible for substantial electricity consumption and peak demand in most of the United States. Over the past decade, energy conservation researchers have studied air conditioning more and more. Much of this research has focused on the impact of air flow, duct leakage, and refrigerant charge level on cooling performance.

One area, which has been neglected by researchers, is fouling of evaporator and formicary corrosion. Known commonly as ant’s nest corrosion, champagne leaks, or just simply as formicary, the issue presents as a hard to detect leak within the fin pack of an evaporator coil. This tiny leak or set of leaks results in loss of system refrigerant over time. While the incidence of formicary corrosion is low nationwide, it is more prevalent in warm, humid climates found in southern portions of the United States where slimy biofilms coat the coil fins.

 WHAT CAUSES IT

The tunneling action that leads to corrosion is caused by the presence of organic acids mixed with moisture on the copper tube within the fin pack. Two common acids known to cause formicary corrosion are formic and acetic acids. Certain manufacturing oils and lubricants can contain compounds that form these organic acids, but common household items can also breakdown to form formic and acetic acids. These can include building materials like formaldehyde adhesives, foam insulation, and laminates, as well as personal hygiene products like cosmetics, disinfectants, deodorizers, and cleaning solvents. To initiate corrosion, the presence of water is necessary. The corrosion rate is aggravated by the presence of mold biofilm that keeps the fins wet.

 HOW TO REDUCE IT

Every technician will tell you that every time they look at these coils, they are dirty with mold biofilm. A standard part of routine A/C maintenance and residential commissioning is to clean the evaporator coil with a wire brush and detergent or other cleaning chemistry, and to clean the outdoor coil of leaves and other debris. Over the last 20 years, the simple use of appropriate germicidal UV light can prevent this and keep the coil clean and free of any biofilm buildup.

The presence of mold biofilm on cooling coil acts like a water sponge that keeps the fins constantly wet and sticky, which capture and retain particulates and chemical contaminants, thus enhancing the formic acid corrosion rate. When the biofilm is eliminated with an efficient germicidal UV system, the coil is not permanently wet, does not trap and retains as much contaminants, and consequently its corrosion rate is greatly reduced.

 

Buildup of mold biofilm in lower right hand corner completely blocks air flow

Coils normally foul due to bioaerosols and other biologically active materials, which are ubiquitous in hot climates. This usually also lead to significant indoor air quality problems that can trigger respiratory allergic responses of building occupants.

 

Fungal biofilm growth on a residential (Left) and commercial (Right) cooling coil

The biofilm that causes evaporator fouling and its accelerated corrosion also impacts on the cooling performance and energy efficiency. Large commercial heating and cooling coils have the same problems and are prone to the same type of fouling and consequential corrosion issues. Their lifespan can also be increased notably by using an appropriate UV germicidal system that prevents mold buildup in hot and humid climate.

The first step to take to reduce the formicary corrosion due is to prevent the formation of a biofilm of molds and fungi with an adequate germicidal UV system. Biofilm-free fins will be less susceptible to retain dusts and potentially corrosive compounds, as well as the moisture that activates the corrosion effect.

References

Siegel, Jeffrey, I. Walker & M. Sherman. 2002. “Dirty Air Conditioners: Energy Implications of Coil Fouling” Submitted to the 2002 ACEEE Summer Study on Energy Efficiency in Buildings.

Siegel, Jeffrey A. and W.W. Nazaroff. 2002. “Modeling Particle Deposition on HVAC Heat Exchangers.” Submitted to the Indoor Air 2002 conference.

Siegel, Jeffrey and I.S. Walker. 2001. “Deposition of Biological Aerosols on HVAC Heat Exchangers.”

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Effect Of Germicidal UV On Plastic Materials

Much of the effect of sunlight on materials has been attributed to the UV component (IESNA 2000), UV can fade some wall paints, wallpapers, and drapery fabrics (GE 1950). Some materials may have high UV reflectivity, like aluminum, or have high transmissivity, like quartz which absorbs very little UV. The absorption of UV by itself, is not necessarily an indicator that UV damage may occur, since it is the photochemistry which determines material effects. The total absorption is, therefore, an indicator of the potential for photodegradation in materials, while reflectivity can indicate protective effects.

UV photons energy vs. chemical bonds

When polymers are exposed to ultraviolet light, i.e. 100–400 nm wavelength, the photons energy exceeds the bond energy of the carbon bonds in the polymer or else exceeds the activation energy of chemical reaction (Moreau and Viswanathan 1976). The depth to which ultraviolet light penetrates the polymer creates a region of absorption where photochemical reaction may take place, and where photodegradation may occur. Since UV transmissivity tends to be very low for most materials, even at millimeter thicknesses, most of the photodegradation will occur on the immediate surface of a material, to a depth of typically less than 0.01 to 0.1 millimeter. For most common polymers the depth of UV penetration is typically about 0.025 mm to 0.050 mm i.e. 25 to 50 microns.

In the photodeterioration of paints, varnishes, and textiles, the quantum yield is several order of magnitudes less than unity (Feller 1994). For the bleaching of certain dyes the quantum yield has been reported to be about 0.002, meaning a thousand photons must be absorbed before two molecules are bleached. Quantum yields as low as 0.0001 (10,000 photons per molecule) have been reported for most plastics. High quality pure plastics are relatively resistant to UV but impurities and residual solvents in low-grade plastics are mainly responsible for their quick photodegradation.

Yellowing of polymers from ultraviolet exposure tends to be concentrated on the immediate surface. Surface yellowing tends to block UV and protects the inner plastic. The fading of pigments and dyes can be evaluated in terms of the loss in concentration over time (Feller 1994). The depth of discoloration is reduced by the presence of color pigments. As the concentration of pigments increases, the depth of discoloration or fading also decreases.

Plastic properties and protection against degradation

There are as many as thirteen different properties of plastics which can be used as indicators of photodegradation, including coloration, tensile strength, elongation, hardness, degree of polymerization, infrared absorbance, etc. Experimental data indicates the response of most of these properties to extended ultraviolet exposure results in data that can be effectively modeled with exponential decay curves of one or more orders.

Materials that would darken to UV after exposure create a thin UV-proof film on the surfaces of polymers like PVC. This would enable them to develop resistance to further UV exposure (Owen 1976).

The photochemical degradation of materials is a dose-dependent function that depends only on the quantum yield and the molar absorption coefficient at the irradiation wavelength (Bolton and Stefan 2002). It describes the susceptibility of a material to degrade under UV exposure. Associated with this there would be some limiting distance, a film thickness or penetration depth, to which UV would penetrate.

Based on several decades of use, experience has shown that within a few exceptions, the UV induced damages tend to remain superficial and do not generally affect the structural or mechanical integrity of thick plastic components. For critical components such as exposed electrical wire direct insulation coating, it is recommended to cover the wires with aluminum tape or run the wires inside protective metallic rigid or flex conduits according to good practice and general electrical codes prescriptions. Rubbers in general such as motor belts and conduits used in the HVAC industry have proven to stand germicidal UV very well over the last 20 years of cumulated field experience.

Screens of many electronic devices can be affected by UV degradation due to the grade of plastic used and the very thin film generally used. For such devices, protection is easily achieved by installing with a simple glass window of 3 mm thickness over the screen. Transmittivity of common amorphous glass approaches zero for below 370 nm wavelength.

References

IESNA. 2000. Lighting Handbook: Reference & Application IESNA HB-9-2000. New York: Illumination Engineering Society of North America.

GE. 1950. Germicidal Lamps and Applications. USA: General Electric. Report nr SMA TAB: VIII-B.

Moreau W, Viswanathan N. 1976. Applications of Radiation Sensitive Polymer Systems. In: Labana SS, editor. Ultraviolet Light Induced Reactions in Polymers. Washington, DC: Ameri- can Chemical Society, pp. 107–134.

Feller RL. 1994. Accelerated Aging: Photochemical and Thermal Aspects. Institute TGC, editor.

Ann Arbor, MI: Edwards Bros.

Bolton J, Stefan M. 2002. Fundamental photochemical approach to the concepts of fluence (UV Dose) and electrical energy efficiency in photochemical degradation reactions. Res Chem Intermed 28(7–8):857–870.

Owen ED. 1976. Photodegradation of Polyvinyl chloride. In: Labana SS, editor. Ultraviolet Light Induced Reactions in Polymers. Washington, DC: American Chemical Society, pp. 208–219.