On this page you will find a comparison of indoor air quality systems utilizing filterless technology based on Oxidation, Ozone and/or UV light (also see HEPA Filtration, Air Filters and Needlepoint Ionizers)
Ultraviolet Light and Ozone receive a lot of attention concerning indoor air quality. Both are nothing new. They have been used for decades in hospitals, medical applications and the food industry. This technical overview will outline each of the technologies and discuss the pros and cons of each.
AHPCO is an Advanced Hydrated Photocatalytic Oxidation technology. Basically, it is a broad spectrum high intensity UV light targeted on a five-metal catalyst in a low-level ozone and moist atmosphere. This creates an advanced oxidation of friendly oxidizers, or very safe and aggressive oxidizers that revert back to oxygen and hydrogen. The AHPCOCell was developed in 2003.
The original AHPCO Cell was designed for use in a central HVAC system. This provides the fastest and most effective oxidizer distribution. Rhodium and improved hydration compounds were added as a catalyst creating a totally new target concept. A 360 degree cell provided maximum exposure of the catalysts. The bulb was reworked and a HE/UV Broad Spectrum 100-3-NM bulb with a heavy duty filament was developed. This combined with a soft start ballast gave the new AHPCO Cell an unprecedented 3 year, 25,000 hour life. This was a major improvement over the current standard 8,000-10,000 hour UV bulb life. The most important improvement was the efficacy, the new cell design created more hydro peroxides and super oxide ions and ozone levels were further reduced to .01-.015 ppm. Country or forest air usually contains roughly .01-.02 ppm of ozone. Most people can smell ozone at .01 ppm, and .05 ppm is the federal safe limit for medical devices. The new cell also produces hydroxide ions and ozonide ions which broadened the scope of its air purification capabilities. This technology is used exclusively in the Air Oasis Air Purifiers
Pros: Low cost, no maintenance (replace cell once every 3 years), easy installation, airborne hydro peroxides, super oxide ions and very low-level ozone (.01 - .015 ppm*) travels through the house providing 24-hour protection against airborne mold, bacteria, viruses, odors and VOCs. The cell also acts as a germicidal lamp and treats the air that passes by it. Note: Federal ozone safety limits are .04 ppm. At .01 - .02 ppm the AHPCO Cell is not considered an ozone device
This is an advanced oxidation technology that consists of a proprietary, high-intensity broad spectrum UV tube (100 300nm) in a hydrated catalytic matrix cell. Low-level ozone is produced in the cell, the majority of which is converted into airborne hydro peroxides and super oxide ions. The UV bulb is encased in a protective poly tube to prevent any glass or mercury breakage/leakage. Also, the entire assembly is encased in a protective metal cell. Note: The Chinese Government has tested and passed the AHPCO Cell for use in preventing SARS in Chinese subways. An advanced version of this technology is used in Air Oasis Air Purifiers
Pros: Low cost, no maintenance (replace cell once every 3 years), easy installation, airborne hydro peroxides, super oxide ions and very low-level ozone (.01 - .02 ppm*) travels through the house providing 24-hour protection against airborne mold, bacteria, viruses, odors and VOCs. The cell also acts as a germicidal lamp and treats the air that passes by it. Note: Federal ozone safety limits are .04 ppm. At .01 - .02 ppm the AHPCO Cell is not considered an ozone device.
This system utilizes a Titanium grid as a catalyst for UV-C (254nm) germicidal light. Air that passes through the grid and comes in contact with the catalyst is purified by Hydroxyl Radicals that are formed on the Titanium grid. Also, the UV-C light rays kill microbials that pass by them.
Pros: Effective on the air that passes through the system for mold, bacteria and VOCs.
Cons: Expensive, large, substantial installation, and not effective on odors. Only treats the air that contacts activated target surfaces as it passes through the unit. Most UV systems install a glass UV mercury bulb without protection from breakage. A broken bulb could release mercury, a potential environmental and health hazard.
These are rapidly becoming very popular as an easy fix for the air conditioner coil mold problem. This is the most prevalent cause of the building mildew smell you get when you enter an air-conditioned sick building. UV-C (254nm) lamps are basically similar to sun lamps and are typically only effective on microbials that pass by within a few inches of the lamp or areas where the light is shining directly on for extended periods of time, such as the air conditioner coil. more info
Pros: Low cost, easy installation, and effective on suppressing mold growth on the coil.
Cons: Not effective at killing airborne mold unless numerous lamps are used only effective on the surface of the coil that is in direct light. This leaves much of the coil with no treatment. Does not provide ongoing room protection. Most UV systems install a glass UV mercury bulb without protection from breakage. A broken bulb could release mercury, a potential environmental and health hazard. Minimum of two lamps must be used to cover at least one-quarter of the coil surface (the upper half of the outer coil). For one-half coverage, three to six lamps must be used. 100% coverage is not practical.
Ultraviolet lamps in the 185nm range produce low-level ozone, just as the sun does, which is very effective in odor microbial reduction and VOCs.
Pros: Low cost, easy installation, and effective on mold, smoke, odors and bacterial. The ozone gas travels through the house to provide ongoing treatment, unlike the UV-Germicidal Lamps where only the air that passes within inches of the bulb is treated.
Cons: Ozone is a concern to some people. Improper systems could produce ozone levels exceeding Federal guidelines. Ozone does not work on all odors and VOCs. Most UV systems install a glass UV mercury bulb without protection from breakage. A broken bulb could release mercury, a potential environmental and health hazard.
Corona Discharge systems simulate lightning with a corona electric arc or spark. Strong ozone is produced by converting the oxygen (O2) to ozone (O3).
Pros: Low cost. Ozone effective on odors, bacteria, mold and some VOCs.
Cons: Air is 80% Nitrogen and 20% Oxygen. These units convert Oxygen to Ozone. They can also convert the Nitrogen to airborne Nitric Acid and Nitric Oxide, which can act as an lung irritant and results in a pungent "metallic" or "bleach-like" odor and causes maintenance problems due to corrosion. They can also generate electromagnetic radiation.
They produce high concentrations and levels of ozone -- erratic, unpredictable production; ozone "blasts" are common -- usually over Federal safe limits. These systems typically will require expensive monitors to control ozone levels. Also, arcing (sparking) can be a noise and safety problem. Note: Corona Discharge Ozone Units should never be used for air purification in occupied areas, as they will usually exceed Federal safety limits of ozone.
Higher more complicated maintenance is required to replace the fragile plates, and there is a higher incidence of product or component failure.
|UV-C Germicidal Lamp||UV-C Ozone Lamps||Corona Discharge Ozone Systems||UV-C Catalytic Oxidation Systems||Photohydro- ionization Systems||AHPCOl|
|Designed for HVAC Systems||Yes||Yes||Yes||Yes||No||Yes|
|Provides whole house air purification||No||Yes||Yes||No||Yes||Yes|
|Keeps mold from growing on AC coil||Yes||?||?||No||Yes||Yes|
|Reduces odors, VOCs, bacteria, viruses and mold throughout the house||No||?||?||No||Yes||Yes|
|Low initial cost||Yes||Yes||No||No||Yes||Yes|
|Low installation cost||Yes||Yes||No||No||Yes||Yes|
|Reduces microbials by over 90% throughout the house||No||?||?||No||Yes||Yes|
|UV-C Germicidal Lamp||UV-C Ozone Lamps||Corona Discharge Ozone Systems||UV-C Catalytic Oxidation Systems||Photo- hydro- ionization Systems||AHPCOCell|
|Provides a broad range of disinfection||No||No||No||Yes||Yes||Yes|
|Low power consumption||Yes||Yes||No||?||Yes||Yes|
|Meets Federal ozone safety guidelines||Yes||?||No||Yes||?||Yes|
|Has the broadest range of effectiveness||No||No||No||No||No||Yes|
|One unit will service a HVAC System||No||Yes||Yes||Yes||?||Yes|
|UV bulb is protected from breakage & mercury contamination||No||No||N/A||No||No||Yes|
It's no mystery that the air inside our homes, offices and nearly every building we enter is contaminated with toxic air pollution problems. But wading through the plethora of air purification technologies and models to make our living and working space free of pollution can be a daunting task, especially with the misinformation presented by so many salespeople and web sites. There are many different air purification technologies and air filters on the market, but no one air purifier technology can solve every air pollution problem, which is why we carry different brands. For help determining which air purifier is right for you, click on one of the below links or call us toll free at 866-875-4386 (US and Canada).
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