Indoor Air Quality

You can’t see poor IAQ, but the pollutants found indoors are from two to five times worse than in outdoor air. In fact you can see only about one percent of the floating contaminants. What’s actually floating around in your air that is making you sniffle or sneeze? A combination of any of the following contaminants could be in the air you’re breathing: dust mites and their feces, mold spores, tobacco smoke, pollen, bacteria, gas molecules like NOx (auto exhaust fumes, etc.), and viruses. Some sources of these pollutants are found in the most common articles such as paints, glues, carpet fibers, plants, pets, and more.

Most odors are associated with types of indoor air contaminants. Odors are actually gases like formaldehyde (a caustic agent), ammonia (pet and body odors), acetaldehyde (tobacco odors), and off-gassing from paints, carpets, and adhesives that your senses detect. Cleaning sprays also emit fumes that are unpleasant and unsafe to breathe in measurable quantities. Personal discomfort, including itchy and watery eyes and coughing, is a visible sign that these contaminants are present. A combination of odor and contaminant control is important to healthy indoor air.

Prolonged exposure to poor IAQ can have long term effects on your body’s immune system. Allergies, asthma, even immune system failure can be traced to excessively poor IAQ.

It is important to know the contaminant sources of your discomfort or allergic reactions. Room air purifiers can adequately remove the contaminants that aggravate your breathing so that you sleep better and live a more comfortable life in your home

Lint ~ All long fibers found in household airborne dust are considered lint. They may be carpet or clothing fibers that break off due to wear and tear. They could be broken segments of cat or dog hair or even human hair. Lint is not typically harmful to your health. However, asbestos fibers, which can come from older floor tile, ceiling panels, blown ceiling finish material, duct or pipe insulation, are a modern-day concern.

Dust ~ Most of the dust in indoor air is the result of dirt’s being tracked onto your floors and carpets. This dirt is repeatedly ground up as we walk on it until it is fine enough to stay suspended in the air. The amount of dust in the air at any given time depends partly on how heavy the foot traffic is inside your home. Dust also comes in with the air that normally infiltrates from the outside via windows, and doors. Except for extremely windy days, this dust is relatively fine in size.

Smoke ~ Indoor smoke commonly comes from smoking tobacco or overheating the fat or cooking oil in the kitchen. However, burning candles produce large amounts of smoke as indicated by the incomplete combustion of the yellow flame. The gas flame of a range or other appliance will result in little smoke so long as it has a blue color. Your fireplace or wood-burning stove can put smoke into your house if the system is not operating properly. Your neighbor’s fireplace, even if operating correctly, can put smoke into your house via infiltration air.

Grease Aerosol ~ Skillet or deep-fat frying inevitably causes grease spatter and smoking. Some of the smoke condenses as it cools to form tiny grease droplets, or aerosol. A wide range of particle sizes results from frying.

NOx ~ These automobile exhaust fumes migrate into a home through natural infiltration air.

Pollen, Mold, and Plant Spores ~ Pollen and plant spores generally get into your house with the infiltration air from the outside. Some such as goldenrod pollen are very large particles and don’t move far from the plants. Ragweed and grass pollens are smaller and are more easily kept suspended by the breezes. Some plant spores and mold spores can originate inside your home, especially in areas of high humidity such as bathrooms, closets, and basements.

Viruses and Bacteria ~ Both viruses and bacteria may be present in residential air under normal conditions. Bacteria are much larger (0.3 to 30 microns) than viruses (0.003 to 0.05 microns) but both are known to piggyback on larger dust particles. Thus, viruses in particular may not be as difficult to capture as their size would indicate.

There may well be more than 400 million unseen particles in one cubic foot of indoor air. The number of particles may remain nearly constant because new particles are being created as old ones attach themselves to surfaces.

Because the behavior and control of particulate pollutants are so greatly influenced by their size, the more important types are listed in Commonly Found Household Contaminants.

The size of the micron is very small. It takes more than 25,000 microns to make one inch. The very finest human hair, for example, is thirty microns thick. Most of the dust one sees on tabletops in the home is lint.

The dancing sunbeams of dust we see are mainly lint. Lint is a constant nuisance requiring frequent dusting, but is not important in permanent soiling of walls and furnishings or in health effects except for asbestos, which is rarely found in today’s modern homes.

Second-hand tobacco smoke is proven to be a definite health hazard as are the fine carbon particles resulting from incomplete combustion (yellow flames). All fine particles can have odor molecules attached, but this fact is especially true of tobacco smoke.

Pollens along with mold and plant spores can cause allergy problems and odors. Most of the pollens and plant spores originate outside the home. Because these spores are relatively large, they can be partially controlled by maintaining a tight residence. Prolonged exposure to certain mold spores (e.g. stachybotris) can cause severe long-term damage to the immune system.

HEPA air purifiers are particularly helpful with dust mites, which are believed to be the worst offenders in the realm of allergy suffering.

Particles in the Air
The dancing sunbeams of dust we see are mainly lint. Although lint is a constant nuisance requiring frequent dusting it is not important in permanent soiling of walls and furnishings or in health effects except for asbestos, which is rarely found in newer homes.

Room air purifiers provide relief from the dusting nuisance though the presence of dust on counter tops does not mean the air purifier is working improperly. Many lint particles are too far from and too heavy to be affected by most air purifiers on lower fan speeds.

The following are micron measurements for the more commonly found indoor air contaminants:

Lint is as small as ten microns.
House Dust (suspended) particle sizes vary due to the amount of times they have been broken down from foot traffic. The range is from 0.001 to twenty microns.
Lung Damaging Dust is from 0.5 to five microns.
Tobacco Smoke is between 0.01 and one micron.
Cooking Oil Smoke (grease spatter) is between 0.03 and twenty microns.
Viruses range between 0.003 and 0.05 microns.
Bacteria is 0.3 to thirty microns.
Pollen and Plant Spore particles are as small as seven microns.
Pet Dander is between 0.5 and ten microns.

There are three basic types of air purifiers: mechanical, electronic, and hybrid models. Each of these types uses different processes in order to purify the air to the best of its ability.

Mechanical air purifiers, which utilize fans to pull air through a series of filters, are the most common type of air cleaner. Typically they employ a pre-filter to catch large particles and a HEPA filter to trap particles down to 0.3 microns and remove them from the air. These air purifiers, while effective removing particles, have very little effect on odors.

Electronic air purifiers electrify pollutants and capture them in different ways. Electrostatic models use an electronic field to trap charged particles. These particles are captured on a series of flat plates which require repeated cleaning. Ionizing air purifiers change the electric polarity of the airborne particles. This type purifier charges the particles in a room so that they are attracted to walls, floors, tabletops, draperies, occupants, etc. While ionizing air purifiers do take the particles out of the air, they will not remove them from the living space, thus making them ineffective at reducing allergens. Newer models use a hybrid of the above mentioned technologies, combining two or more of the particle removal devices.

Allied Ion/HEPA combines the mechanical filtration of its HEPA filters with the ion generator. This combination results in the elimination of 99.97% of the particles down to 0.3 microns with the added benefit of reducing the odors in the air rapidly.

micron

A micron is a unit of size measurement for matter that is generally invisible to the naked eye. A micron is one millionth of a meter or 1/1000 of a millimeter. At best a human can see a ten to thirty micron particle without the aid of a magnification device, which is about the size of the smallest human hairs. It takes more than 25,000 microns to make one inch!