Introduction

At Renaissance Medical Supply we are concerned about environmental air quality indoors and out but the scope of this fact sheet is limited to indoor air quality and residential air cleaning appliances. We have assembled a list of important facts from publications of the US Environmental Protection Agency , the American Lung Association, the National Institute of Occupational Safety and Health, the Federal Trade Commission, and the American Academy of Allergy and Immunology. By using reliable scientific information from these government and professional sources we can answer the two most important questions about indoor air quality. These are:

1. Is indoor air pollution really a health risk?
2. What can be done about it?

The United States Environmental Protection Agency has produced several publications related to indoor air quality. These are available to the public by mail or at the EPA website. Here is a list of facts obtained from these EPA publications.

• Indoor air pollution is a real health risk and one that you can do something about.
• Indoor air pollution is listed among the top five environmental risks to public health.
• The air inside of homes and other buildings can be more seriously polluted than the outdoor air. Studies indicate that indoor levels of pollutants may be 2-5 times, and occasionally more than 100 times, higher than outdoor levels.
• Most people spend about 90% of their time indoors. This increased exposure leads to a greater health risk from polluted indoor air than from outdoor air pollution.
• People who are most susceptible to the effects of indoor air pollution are often those with the longest periods of exposure. These include the elderly, the very young and the chronically ill.
• Most homes have more than one source contributing to indoor air pollution. The cumulative effects of these pollutants can present a serious health risk.
• Indoor pollution can be from sources inside or outside the home.
• The primary cause of indoor pollution is the release of particles or gases by indoor sources.
• Inadequate ventilation can be a cause of increased pollutant levels.
• Modern energy efficient construction can reduce infiltration of fresh air from outside resulting in higher concentrations of pollutants from indoor sources.
• High temperature and humidity levels can also increase concentrations of some pollutants.
• Combustion sources include oil, gas, kerosene, coal, wood, and tobacco products.
• Some sources, such as building materials, furnishings, and household products like air fresheners, release pollutants more or less continuously.
• Outdoor sources include radon, pesticides, and outdoor air pollution.
• Other sources may be related to activities carried out in the home and release pollutants intermittently. These include smoking, the use of ozone generating air cleaners/purifiers, paint, solvents and strippers used in hobbies, crafts and decorating, cleaning products and pesticides. High pollutant concentrations can remain in the air for long periods after some of these activities.

In some publications the EPA breaks down indoor air pollution into three main types. These are particles, gases and radon and it's progeny.

• Particles are very small solid or liquid substances that are light enough to float suspended in air (e.g., mists, dust, or pollen). They can be composed of smoke, human and animal dander ( dead skin ), house dust, pollens, mold spores, or dust mites and their debris.
• Small, invisible respirable-size particles have a higher probability of penetrating deep into the lungs, where they may stay a long time and may cause acute or chronic effects. These include cigarette smoke, viruses, bacteria and some molds.
• Environmental tobacco smoke (ETS) also called "secondhand smoke," a major indoor air pollutant, contains about 4,000 chemicals, including 200 known poisons, such as formaldehyde and carbon monoxide, as well as 43 carcinogens.
• Some larger particles, such as some molds, pollen, animal dander, and house dust allergens do not penetrate as deeply, but may cause allergic reactions.
• Gaseous pollutants include combustion gases and organic chemicals which are not associated with particles. Hundreds of different gaseous pollutants have been detected in indoor air. Adverse health effects can be anything from irritation or allergic reactions to organ damage or cancer.
• Radon and its progeny are radioactive pollutants from natural sources such as rock, soil, groundwater, natural gas, and mineral building materials. They have the potential to cause lung cancer. Radon is a gas which produces short-lived progeny ( radon daughters ) in the form of particles, and can become attached to larger particles. Radon progeny may deposit in the lungs and represent the main health hazard from the radon series. Air cleaners generally will not remove radon but some are capable of filtering out radon daughters.

According to the American Lung Assosiation and the US Environmental Protection Agency the three strategies for reducing pollutants in indoor air are source control, ventilation, and air cleaning.

Source Control is the most effective means of reducing airborne contaminants. It can mean eliminating some sources or reducing their emissions. Listed below are some suggested source control strategies.

• Don't allow smoking indoors or at least restrict it to a well ventilated area. Current EPA estimates are that second hand smoke is responsible for 3000 lung cancer deaths and 35,000 to 50,000 heart disease cases in non-smokers annually.
• Don't allow smoking around children. Between 200,000 and 1,000,000 asthmatic children have their condition worsened by exposure to second hand smoke.
• Don't allow pets indoors or at least restrict their access. Animal dander is a major allergen.
• Look for natural cleaning products and other household products that do not emit pollutants known to be hazardous.
• Use a HEPA vacuum or central vacuum system when cleaning. A regular type vacuum cleaner can redistribute particles that have settled out of the air.
• Deal with dust mites. Dust mites and their feces and body parts are powerful allergens. They thrive in areas like furniture and bedding where they feed on dead skin from humans. Vacuum all bedding with a HEPA or central vacuum. Vacuum everything on, over, under or around the bed. Wash bedding regularly with water hot ehough to kill dust mites or put the bedding in the freezer after washing as cold temperature will kill mites also. Use mite proof covers for pillows and mattresses.
• Avoid products that offgas formaldehyde or other toxic chemicals. Examples include some types of urea insulation, particle board, permanent press clothing and paper products.
• Store solvents, pesticides and other toxic substances in a separate structure when possible.
• Reduce pesticide use.
• Avoid dry cleaning.
• Reducing temperature and humidity can help reduce pollution from molds, mildew, dust mites and offgassing.
• Do not use ozone generators in occupied spaces.

Ventilation is the next most effective means of improving indoor air quality. Ventilation brings outside air indoors. This causes polluted indoor air to be forced out and also dilutes contamination in the remaining air. The simplest means is opening windows and doors. Most homes have laundry, bathroom or kitchen fans that exhaust indoor air causing fresh air to be drawn in from where ever it can leak in. Limitations of this method are the cost of heating or cooling the fresh air and the possibility of bringing in more pollution or allergens during times of poor outdoor air quality.

Air cleaning devices alone cannot assure adequate air quality but can serve as an adjunct to source control and ventilation. After doing everything possible to reduce pollution by means of source control and ventilation some types of air cleaners will help to further reduce pollution by removing particles and gases from the air. Air cleaning measures can be particularly useful when outdoor pollution levels are too high to ventilate with fresh outdoor air.

There are three basic types of air cleaners on the market. These are mechanical filters, electronic air cleaners, and ion generators. Mechanical filters work by catching and holding particles as air is forced through them. The material that captures the particles is called the media. Electronic air cleaners use an electric field to capture charged particles. Usually a high voltage is used to add an electrical charge to particles as they pass through in the air stream. Particles are then attracted to and captured on oppositely charged collection plates in the air cleaner unit. Some types of electronic air cleaners use charged filter media instead of plates. Ion generators spew out ions that add a charge to particles in a room causing them attach to each other or to walls, floors, ceilings, furnishings and occupants. Some use a collection plate to capture some of the charged particles in the unit. Some devices may use a combination of these technologies. Electronic air cleaners and ion generators may produce, either intentionally or as a by-product, the toxic gas, ozone. Consider these additional facts about air cleaners:

• A type of mechanical filter called extended media adds pleats to the media, greatly increasing the surface area available to capture particles and reducing the resistance to air flow.
• HEPA Filters are the most efficient mechanical filters for removing respirable size particles which are most likely to be breathed deep into the lungs and remain there. HEPA originally meant high efficiency particle arrestor but is now called high efficiency particle air filter. The design of these filters is aimed at particles of .3 microns ( respirable size particles ) because they represent the greatest risk to health. One micron is one millionth of a meter and a human hair is about 75 microns in diameter. True HEPA filters are designed and tested to remove .3 micron sized particles at a minimum efficiency of 99.97% with higher efficiency for both smaller and larger particle sizes.
• Some HEPA type filters that are not labled as "true HEPA" filters may not have the same efficiency.
• HEPA filters, because of their high efficiency, restrict air flow more than other types of filters and are therefore not generally suitable for use in central heating or cooling systems where restricted air flow could damage the system. For this same reason portable appliances utilizing true HEPA filters must have powerful fans to move the air through them.
• Hepa filters actually become more efficient with use and have a long maintenance free life cycle of up to 5 years

• Electrostatic filters have charged fibers in the filter media that attract and capture particles as the air passes through the filter. This can be a filter element designed to replace the standard element in a central system or a stand alone air cleaner that uses this technology. The media can be disposable or permanent and washable. Some types have a permanent charge while others require an electrical connection to maintain the charge on the filter media.
• Electronic filters generally have the disadvantage that they become less efficient with use and require frequent cleaning or filter changes.
• Electrostatically charged extended media filters such as the ones made by 3M can be much more efficient than standard furnace filters. These filters are so efficient that they must be changed on a regular basis or they can restrict air flow.

• These are very inexpensive to operate and require little or no maintenance. However, units with collector plates are more effective and these require frequent cleaning.
• Walls and furnishings may be stained by the charged particles deposited on them.
• Ion generators, particularly those that do not trap some of the charged particles will cause some particles to be deposited in the respiratory tract. Some experiments have shown that particle deposition increases with increased charge; therefore, the use of ion generators may not reduce the dose of particles to the lungs.
• Many ion generators also produce ozone. If you consider an ion generator make certain that it does not produce this highly reactive and toxic gas.

• Some air cleaners include a chemical filter to remove gaseous pollutants. Charcoal is effective and commonly used to remove volatile organic compounds (VOCs). Since charcoal is not effective at removing low molecular weight VOCs like ammonia and formaldehyde, some units also include chemisorbant materials that removes these chemicals.
• Since the efficiency of gas phase filters decreases as they capture more pollutants, some manufacturers use large amounts of sorbant material.

• The marketers of these devices claim that ozone removes air contaminants from indoor air by oxidizing airborne gases, and even particulates, to harmless carbon dioxide and water vapor. The basis for these claims is the fact that ozone will react chemically with many substances it comes into contact with. Scientific studies indicate that these reactions may actually produce more hazardous substances than they eliminate.
• Ozone is a toxic gas. It is used effectively for water purification and such things as controlling microbial growth in unoccupied spaces.
• The American Lung Association concludes that ozone is a health risk in occupied spaces and does not suggest the use of ozone producing appliances sold as air cleaners.
• The EPA concludes that at concentrations that do not exceed public health standards ozone is not effective in reducing indoor air pollution.
• Those who market these machines have referred to their ozone (O3) output as trivalent oxygen, activated oxygen, mild ozone and other misleading names but whatever you call it, it is still a toxic gas.
• There is no difference between the ozone that these machines put out and the outdoor ozone that is a major national health concern.

Based on the evidence presented and conclusions drawn by the US Environmental Protection Agency, the American Lung Association, the National Institute of Occupational Safety and Health, the US Food and Drug Administration, the Federal Trade Commission, the National Air Filtration Association and the American Academy of Allergy and Immunology, are the following conclusions and observations.

• Indoor air pollution is a serious problem that can cause or aggravate respiratory illness especially in children, the elderly or those already afflicted with respiratory conditions.
• The three means of reducing indoor air pollution in order of effectiveness are; source control, ventilation and air cleaning.
• Although no scientific studies have been done to prove beneficial health effects of air cleaners, two related facts are proven; 1.) Indoor air pollution is a commom problem and can damage health and 2.) certain air cleaning devices do remove pollutants from indoor air.
• The most efficient filter for removing the most dangerous respirable sized particles is a true HEPA filter.
• If a room air cleaner is to be used a unit with a HEPA filter will be most useful.
• Activated charcoal and chemisorbants can remove VOCs.
• Ion generators are not effective unless used with other methods.
• There is a lot of information about the ineffectiveness of ozone that is not presented here. It is enough to note that ozone is a health risk and should not be introduced into human occupied spaces.
• In places where clean air and personal safety are absolutely critical such as hospital operating rooms and military or industrial clean rooms, ozone generators are not used for air cleaning. These facilities generally use HEPA filtration and activated charcoal.
• The DOP method in Military Standard 282, used to rate particle reduction by high efficiency particle air filters, is the only standard published by the federal government for use in determining how well an air cleaner works in removing pollutants from indoor air.

Air cleaning effectiveness

The Austin Air filters use up to 60 square feet of true medical HEPA filter paper. The Austin units incorporate up to 15 pounds of activated charcoal impregnated with zeolite to enhance filtration of gases and odors. A cotton pre-filter is included to prevent the carbon or HEPA from clogging with large "dust" particles. By forcing air through this combination of filters with a powerful permanent split capacitor (PSC) motor, the Austin removes at least 99.97% of particles at .3 microns in size while eliminating over 3,000 toxic gases and odors. For over 12 years Austin Air has been perfecting portable room air cleaner design.

Cost

Because the Austin is designed to be an air cleaning machine without a lot of unnecessary bells and whistles it is priced below other machines in its size class. The Austin is also designed with a large enough filter to last for 5 years under normal conditions. Some competitors units can cost up to 5 times as much over a 5 year period. Even the relatively inexpensive units from home improvement centers will usually cost more to operate over time.

Maintenance

Every month you need to vacuum the outside of the unit to clean the pre-filter. The main filter cartridge needs to be replaced (a very simple task) about very 5 years depending on usage.

Warranty

Austin Air products have a 30 day no-questions-asked, money-back guarantee. The air cleaner is warranted to be free from defects in material and workmanship under normal residential use for five years from the date of purchase. The filter has a pro-rated 5-year warranty, by far the most comprehensive in the industry.

Design considerations

• The Austin Air main filter is designed to work trouble free for five years. Some competitors require purchases of $150 to $300 per year in replacement filters to even honor their warranty.
• Austin uses all welded steel construction with a baked on finish that does not offgas.
• No plastic parts are used in Austin Air filters except the fan blade, wheels or feet and the speed control knob.
• The filter is sealed so that no air escapes being filtered. In some competitors models dust builds up where air has leaked around the main filters.
• The fan and motor are placed in the air stream downstream of the filter and are never subjected to a flow of unfiltered air. Many competitors models pull unfiltered air accross the electronic components and the working parts collect a layer of dust.
• The Austin directs a powerful stream of filtered air away from the unit at high velocity. This results in only unfiltered air being drawn into the machine and is the reason that the Austin can be rated for a larger size room than some comparably sized units. Some designs attempt to exhaust the filtered air over a larger area and at lower velocity in order make the machine quieter. While it does make the machine quieter it reduces room air mixing by circulating air around the machine rather than around the room and it filters the same air over and over.
• Another advantage of the directed air stream is what Austin calls the clean air pocket. By turning the machine so that the discharge is directed toward you a HEPA clean envelope of pure air will surround you in seconds.
• The Austin being square is more stable and easier to move (especially on carpet) than round or rectangular units because its large castors are spaced farther apart.

This article is far from exhaustive and could not possibly cover all types and configurations of residential air cleaning devices. Nor could it cover all aspects of indoor air pollution. But the facts presented are reliable. Austin Air products are available at the Renaissance Medical Supply website or you can get the latest pricing information by calling toll free 1-877-203-1210.

Health Mate See the Heathmate in our store

The Austin Air Healthmate cleans up to 1500 square feet, with 15 lbs of carbon-zeolite mix and True Medical HEPA filter media. The best filter for general coverage.

Health Mate Plus See the HealthMate Plus in our store

The Austin Air Healthmate+ uses the same Healthmate filter and True Medical HEPA filter media with an extra element carbon-zeolite mix. This impregnated carbon enhances chemical absorption. The best filter for multiple chemical sensitivities.

Allergy Machine See the Allergy Machine in our store

The Austin Air Allergy Machine cleans up to 1500 square feet, with strategically placed military carbon cloth and True Medical HEPA filter media. The best filter for allergy and asthma sufferers. The desgn places the High Efficiency Gas Absorption (HEGA) military carbon cloth inside the HEPA increasing it's useful life.

Health Mate Junior See the HealthMate Junior in our store

The Austin Air Jr. cleans up to 700 square feet, with 6.5 lbs. of Carbon-Zeolite mix and True Medical HEPA filter media.

Health Mate Junior Plus See the HealthMate Junior Plus in our store

The Austin Air Jr. Plus cleans up to 700 square feet, with 6.5 lbs. of Carbon-Zeolite mix and True Medical HEPA filter media. Has the same extra absorption mix as the Healthmate Plus.

Health Mate Junior HEGA See the HealthMate Jr. HEGA in our store

The Austin Air Jr. HEGA cleans up to 700 square feet, with strategically placed military carbon cloth and True Medical HEPA filter media. A smaller version of the Allergy Machine.