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Purchasing and Maintaining Abatement Technologies® CAP® Systems
Abatement Technologies CAP Whole-House Air Purifiers are sold and installed by professional HVAC contractors. Click to find a CAP dealer near you.
To maintain peak performance, the inexpensive first stage pre-filter should be replaced monthly. In the CAP100 series, the secondary filter could be changed every 6 months. In the CAP600/1200 series, intermediate filters are changed when the amber 'change filter' lamp illuminates. True HEPA filters are replaced every 2 to 3 years, HEPA-type filters every 1-2 years. Contact your installing dealer for an annual replacement filter and lamp kit.
For best results, replace yearly. CAP UV-C and UV "Plus" products are equipped with high quality, high-output U.S.-made lamps for optimum performance and reliability. The hard quartz lamps are rated for at least 9,000 hours (1 year) when installed and used in accordance with the operating manual. Lamps may last much longer in some situations, but annual lamp replacement is recommended since the UV output of any lamp typically starts to drop off after about 9,000 hours. On/off lamp cycling will reduce lamp life.
There really is no comparison. The 1"-deep electrostatic filters use a charged plate to capture airborne particles. They do not remove VOCs or odors, have very limited effectiveness against molds or bacteria and have very little dirt-holding capacity. The 90%-95% particulate "arrestance" ratings claimed for these filters may sound impressive, but they are misleading. Average particulate efficiency under the more meaningful ASHRAE MERV ratings is very low. The effectiveness of electrostatic filters also drops off quickly as they become dirty, so homeowners must remember to clean them frequently. CAP filters capture a wide array of contaminants, have high MERV ratings and exceptional dirt holding capacity and become even more efficient as they capture air pollutants.
Common sense dictates that even the most effective portables are primarily beneficial in only one room or area. Even if they could somehow pull air in from all over the house, the most powerful models would clean the air only once an hour in an average size home. Effective air cleaning requires at least 3 to 4 air changes per hour (ACH). You could buy multiple portable units and place them throughout the house, but that would be very costly and disruptive. Users of in-room units often complain about their noise and appearance, and the space they take up. CAP whole-house units utilize the central HVAC system to supply purified air to the entire living area, and are located out of the way usually hidden in a basement, crawl space or attic. Learn more about Abatement Technologies Whole-House HEPA Purifiers vs. room units.
These devices, which capture particles on charged plates or grids, are also known as ionizers or electrostatic precipitators. They are far less efficient than a true HEPA filter, even when the collection plates are clean. As happens with electrostatic filters, their efficiency will drop off precipitously as the collection plates get dirty, and homeowner cleaning and maintenance becomes an issue.
Installation and Safety Questions
Several safety measures protect service technicians and homeowners from eye or skin UV exposure, including a lamp shutoff switch, and a sight glass or LED indicator for safe and easy lamp inspection. A protective cover with a safety interlock switch immediately deactivates the lamp before the service technician or homeowner can access or service the unit.
Ozone is similar to chlorine, another strong oxidizer. A glass of pure chlorine would be toxic, but you probably would not want to swim in pool water or drink tap water that has not been properly purified with chlorine. The same is true with ozone, which is also often used for water purification. Unlike in-room purifiers that emit ozone directly into the occupied living space, CAP units with UV "Plus" lamps, utilize the HVAC ductwork as the "ozone chamber" to dissipate ozone effectively. These models have been independently tested and certified to meet stringent ozone safety standards established by Underwriters Laboratories.
Health and Benefit Questions
For health benefits, physicians who treat people afflicted with allergies, asthma and other respiratory ailments frequently emphasize the importance of minimizing or avoiding exposure to airborne pollutants that can trigger adverse reactions.
For equipment benefits and energy savings, studies have shown that a small amount of dirt accumulation on critical HVAC components, such as the A-coil, can significantly reduce system efficiency. Keeping these components clean can therefore help reduce utility bills.
Cleaning and vacuuming remove dirt and other visible contaminants settled on floors and other surfaces, but when it comes to airborne pollutants and allergens, it's what you can't see that can hurt you. Studies have shown that more than 99% of airborne particles are smaller than 1 micron in size (0.00004") and invisible to humans. Particles this small can remain airborne for hours or days. Vacuuming can often worsen the problem by stirring up microscopic particles that have settled. Most home vacuum cleaner filters are not efficient enough to capture particles this small, so they can be spewed back out into the air.
Probably not. Most throwaway furnace filters are only about 5% to 10% efficient, and even less effective against smaller size particles. Dr. Charlene Bayer, director of the Georgia Institute of Technology's Indoor Environmental Research Program, refers to these throwaway filters as "boulder catchers" that "don't catch fine dust particles and don't catch microbes." Dr. Bayer adds, "They don't do anything to help human health."
Visit our Links & Articles page to learn more about allergies, asthma and IAQ.
HEPA Benefits and Effectiveness
According to a 1997 American Lung Association publication, "Because of its high efficiency at filtering out tiny particulates, HEPA filtration is recommended for those individuals who suffer from allergies, asthma or other respiratory problems." HEPA filters have been used for many years in medical, pharmaceutical, nuclear and asbestos and mold abatement applications. An extensive study published in the 1995 American Journal of Respiratory and Critical Care Medicine determined that long-term exposure to high levels of fine particulates is associated with higher mortality risks and shorter life span. Abatement's CAP600 and CAP1200 HEPA Air Purification Systems are often purchased as a direct result of specific recommendations from allergists, pediatricians and other physicians.
The 0.3 micron size was selected for HEPA testing because it is the most difficult to capture. Testing by filter manufacturers and filter testing companies has shown that HEPA filters can actually be more efficient than 99.97% for capturing particles smaller or larger than 0.3 microns.
Germicidal UV and UVP Effectiveness
Yes, according to The Centers for Disease Control and Prevention (CDC) 2003 Guidelines for Infection Control in Healthcare Facilities, which state: "UVGI is effective in reducing the transmission of airborne bacterial and viral infections in hospitals, military housing and classrooms". The CDC Guidelines also state: "In duct irradiation systems, UV lamps are placed inside ducts that remove air from rooms, to disinfect the air before it is recirculated. When properly designed, installed, and maintained, high levels of UVGI can be attained in the ducts with little or no exposure of persons in the rooms." Also, "The use of fans or HVAC systems to generate air movement may increase the effectiveness of UVGI if airborne microorganisms are exposed to the light energy for a sufficient length of time."
Off-gassing from synthetic furnishings and building materials such as carpeting and particleboard products, paints, cleaning supplies and tobacco smoke can produce gaseous pollutants known as volatile organic compounds or VOCs. Examples include formaldehyde, perchloroethylene, toluene, benzene and xylene. Scientists have now discovered that molds and fungi can also give off metabolic gases that contain VOC emissions.
Bioaerosols are airborne particles from living organisms such as bacteria, viruses, fungi, molds (a type of fungus), pollens, dust mite and insect remains, and pet dander that are suspended in the air. Bioaerosols have been identified as a major source of "Sick Building Syndrome" that may cause infectious diseases and allergic reactions such as asthma, pneumonitis, rhinitis, allergic sinusitis, hypersensitivity and fatigue. Molds, pollens, dust mite fecal products and pet dander are among the leading causes of respiratory allergic or asthmatic reactions in the indoor environment.
Allergies and asthma rates are increasing dramatically, and the medical and scientific community is learning more and more about the role of molds on health. It is estimated that 25% of all children and up to 10% of adults are allergic to molds such as Aspergillus, Penicillium and Stachybotrys. The number may be higher. A 1999 Mayo Clinic study found that 96% of the sinusitis cases studied involved mold/fungal infections.
The effectiveness of germicidal UV-C is limited once molds, which are more resistant to UV energy than airborne bacteria, have already formed on surfaces. High-intensity UV-C can help to inhibit the formation of new mold growth on irradiated surfaces, and control the formation of mold spores.
The high output UV-C lamp in the CAP500-UV model, which does not produce ozone, provides the best results in above-coil installations. This location allows the lamp to continuously expose bacteria and other microorganisms on the exposed surfaces of the coil fins to high levels of germicidal UV.
The UV "Plus" lamp in the CAP500-UVP model combines UV-C irradiation and ozonation for enhanced performance against molds and mold-related odors. This model must be installed on the return side, to allow the ozone gas to penetrate into the downstream HVAC components most susceptible to mold growth and microbial odor generation. The UV "Plus" model is especially effective for controlling microbial growth and odors in the hidden recesses of the heat exchanger, and in other locations difficult to irradiate effectively with a UV-C lamp.
For the best of both worlds, when the homeowner budget permits, a contractor can install a UV "Plus" model in the return and a UV-C model in the coil.