Q&A Germicidal Air Purifiers
What is UVC?
UVC is a type of ultraviolet (UVC) energy in the 260-nanometer frequency. The "C" wavelength is the most germicidal in the UVC spectrum.
How does it affect germs?
UVC light is germicidal; it deactivates the DNA of bacteria, fungi, mold, mildew, viruses, spores and dust mites and their feces destroying their ability to reproduce, greatly reducing illness and disease.
Does it work?
UVC Emitters improve IAQ (indoor air quality); kill or inactivate surface and airborne microorganisms; prevent the spread of infectious diseases caused by bacteria; continuously clean coils, drain pans, plenums and ducts; and improve product quality, shelf-life and yield in processing plants. For greater detail, please view the Case Studies section of our website.
Does UVC relate to UVGI?
The two terms are basically synonymous. Ultraviolet Germicidal Irradiation (UVGI) is a term used by Federal Agencies such OSHA, NIOSH and the CDC when referring to UVC.
Can UVC save energy?
Yes. UV-Germicidal devices degrade organic buildup in coils, keeping coils continuously clean. This lowers HVAC energy costs by improving heat transfer and increasing net cooling capacity.
Will it help allergies?
Bioaerosol-related allergies have shown abatement and complete remission when UVC is used in HVAC equipment. Even simple stuffy noses are reported cleared.
Will UVC kill mold in ducts?
Yes, applying UVC at the coil dramatically reduces the overall activity in the rest of the A/C system as well as the space. There is scientific evidence of this by Dr.'s Richard Shaughnessy and Estelle Leviten, Tulsa University. View Scientific Study
Will UVC kill 100% of all airborne microorganisms?
No, however it will kill up to 99+% depending on the organisms and the required design.
Is the product suitable for people with severe allergy or asthma problems?
Yes, UV-Germicidal Light has afforded relief to people suffering from chronic upper respiratory problems. But the device is not limited to households with "special problems." Everyone benefits from the clean, healthy indoor environment that results when your A/C system is bathed in UV-Germicidal Light's energy.
How does UV-Germicidal Light produce a fresh-air smell?
Mold, mold products and decaying matter produce unpleasant or musty odors. In destroying mold, UV-Germicidal Light stops these odors.
Is it affordable?
Some users report that UV-Germicidal Light pays for itself in just months due to lower medical and pharmacy expenses, energy savings and the reduced need for A/C system maintenance. After the initial installation, UV-Germicidal Light costs only pennies per day to operate... consuming about the same amount of energy as a 75-watt light bulb.
What kind of maintenance is required?
No more than an ordinary light bulb - UV-Germicidal Lights are simply changed once a year. They are virtually maintenance-free between change-outs!
Should the Emitters be cycled with the fan or run continuously?
For optimum IAQ and most efficient performance, the devices should be run continuously if possible.
If I see a blue light, does that mean the UVC Emitter is working properly?
Not always. The blue color does not come from the UVC energy but rather from argon gas inside the Emitter. A blue glow indicates that the Emitter is turned on, but it does not provide an accurate measurement of UVC output. That's why you should change UV lamps annually - even if the blue glow still appears to be bright.
Do Emitters need cleaning?
UVC Emitters do not require cleaning as part of normal operation; however, cleaning is recommended if the quartz has been touched during installation. Use 99% pure alcohol and a lint-free cloth.
How do you know when to change the Emitters?
For large or critical applications, change out should be performed when Emitter output decreases by 40% as measured by our radiometer, after about 9,000 hours or 12 months. For installations with no radiometer, change Emitters annually (after about 9,000 hours) Our GeneralAire UVC lamps have QuartzCoat® Durability Effective Lamp Life 18,000 hours (2 year lamp replacement)
How do you dispose of the used Emitters?
Dispose of them as you would any fluorescent tubes, in compliance with your local or state codes.
How does UV-Germicidal Light work?
UV-Germicidal Light uses ultraviolet energy. UVC energy penetrates even the tiniest microbe to destroy its DNA, killing or deactivating it.
Is it harmful in any way?
No. UV-Germicidal Light's non-chemical energy destroys organisms without producing toxic ozone, fumes or secondary pollution. It poses no risk to people, furnishings or equipment. (Direct exposure to the light itself is not recommended.)
Is the technology proven?
Absolutely! UVC products have been installed in buildings all over the U.S. and Asia - including hospitals, schools, offices, public buildings, food processing plants, electric utilities and residences. View the Case Studies section of our website for details.
Where is it installed?
Most UV-Germicidal fixtures are designed specifically for installation in HVACR applications. On existing systems, infestations always exist. Therefore, the best results are obtained when the light is located downstream of and facing the coil. In this location the user can expect the highest efficacy in eliminating surface (coil and plenum), drain pan and airborne microbes. On new systems, it can be placed either up or downstream of the coil and aimed at the coil.
Is it hard to install?
No, installation instructions are available for every model, and CAD layout drawings are often provided when we are informed of dimensional specifics. Depending on the fixture size and style, installation time can average about 15-20 minutes per fixture.
Do you clean a coil first?
UVC will degrade all of the organic material on and within a coil, usually within 30 days or less. Prior cleaning of the coil is not necessary, and may delay the benefits of UVC.
Can UVC be installed in packaged rooftops?
Yes, NEMA 4x (water and rustproof) style fixtures use single ended Emitters that are easy to install in rooftop systems.
How will the customer know it is working?
There are several ways to demonstrate the many things taking place: One is to use a contact plate containing specialized agar before the lights are installed. Thirty days after the lights are installed repeat the procedure and compare results. A visible reduction of mold will be seen in a very short period of time. Coil pressure drop will fall, and can drop as much as 30% in 30 days or less (depending on coil cleanliness and water activity). The system's airflow will usually increase as a result. Drain pans and drain pan water become significantly cleaner. All line-of-site surfaces, i.e. insulation, will start to look like new. Most of the space odor will disappear and the air will seem fresher.
Is UVC harmful?
UVC is only harmful under prolonged direct exposure - which is not generally an issue, since the devices are installed inside air conditioning equipment or are otherwise shielded to prevent exposure. Use of safety goggles and gloves is recommended as a precaution during installation to protect the eyes and skin.
Does it produce ozone?
No, UV-Germicidal devices do not produce ozone or other secondary contaminants.
How will I save money with UVC?
In commercial, industrial or institutional buildings, a Steril-Aire UVC installation offers the most rapid payback in the industry. A typical installation can pay for itself in a few months and save thousands of dollars thereafter in energy and maintenance costs. This is possible because the devices continually clean coils, drain pans, plenums and ducts, reducing or eliminating costly cleaning programs. HVAC energy costs are lowered by improving heat transfer and increasing net cooling capacity. General IAQ is improved for better productivity and less absenteeism. Product quality, shelf life and yield in processing plants are improved as well.
Does it replace filters?
No, a UVC fixture is an air conditioning component that is used in addition to other system parts. These include the coil, heating core, fan, dampers, humidifiers, filters, etc. All are designed to do some form of work within the air handler or on the air.
Don't filters remove microorganisms?
Yes, in an infectious disease application the efficiency and location of a filter should always be a concern. The filter goal is to provide a reduction in the total number of microbes. However, viruses can be as small as 0.02 micron, so the target organism needs to be known to provide a predictable result. More importantly, filters do not abate microbial growth on coils, in drain pans or in plenums and ductwork. UV-Germicidal devices do.
Do I need UVC if I use antimicrobial filters?
UVC is not a replacement for filters. UVC addresses the problem of coil "biofilm" which is usually downstream of the filters. Antimicrobial treated filters rely on direct contact to kill the microrobes. As the filter builds a layer of dirt on it, this direct contact is eliminated and the microorganisms will not be affected by the chemical treatment. Therefore treated filters will not accomplish the task of eliminating the growth on the coil and the subsequent contamination of the breathing zone by those biocontaminants.