Recent studies have shown that a wide variety of such contaminants exist at trace concentrations in all water supplies and in the air.
Ultraviolet germicidal irradiation (UVGI) is a method of disinfection that uses short-wavelength ultraviolet (UV-C) light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions. Ultraviolet irradiation is used in many different environments including food, air and water purification.
UV-C light is weak at the surface of the Earth, as the ozone layer of the atmosphere blocks it. UVGI devices can produce strong enough UV-C light in circulating air or water systems to make them inhospitable environments to microorganisms such as bacteria, viruses, molds and other pathogens. These systems can also be coupled with a filtration system to sanitize air and water.
Since the mid-20thcentury, the application of UVGI disinfection has been an accepted practice and has been used primarily in sterile work environments and medical sanitation.
It is growing in popularity to sterilize drinking and wastewater as the holding facilities are enclosed and can be circulated to ensure a higher exposer to the UV, and more recently UVGI has found renewed application in air purifiers.
UVGI can be installed in rooms that are occupied in a manner that causes air near the ceiling to be irradiated. These are often referred to as upper room air UVGI systems. They are designed so that little of the UV light penetrates into the occupied portion of the room. The purpose is to kill or deactivate the viruses and bacteria within small airborne particles that can often cause infectious diseases. In this way, these systems are used to reduce rates of airborne transmission of respiratory infections, infections at the sites of surgery, and infections of wounds.
Ultraviolet irradiation systems can also be installed in the ducts of heating, ventilating, and air conditioning units and irradiate the small airborne particles containing microorganisms as the air flows through the ducts. In some cases, UVGI systems in the ducts also direct UV light at the cooling coils and drain pans of air conditioning systems. Irradiating cooling coils and drain pans can dramatically reduce mold and bacteria grown on the surfaces that are often wet, such as the cooling coils and drain pans, or they can destroy the microbial films that previously accumulated on the irradiated surfaces.
There are two primary reasons to irradiate coils and drain pans. First, the mold and bacteria that often grow on cooling coils and drain pans may shed particles into the air that subsequently enter the occupied spaces, posing health risks. Second, by keeping the coils cleaner, the UV systems may improve the energy performance of the HVAC systems.
In some hospital settings, UVGI systems are used between in-patient stays in rooms. The units are portable, and effective to the extent of killing airborne particles. These units are designed to rotate around the room directing the beams to cover the entire area. At Universe Optics, we stock a wide variety of UV lenses. We can also custom craft a precision lens to meet your specific requirements.