The Good Air Lady
The Good Air Lady
talks about what you breathe
indoors and out

Air Filtration -- Indoor Quality

Air filtration -- indoor and outdoor quality -- helps remove air pollution problems. Pollutants include vehicle emissions; smoke; industrial emissions; chemical offgassing from cleaners, formaldehyde used in furniture and building materials, and finishes; dander; and dust mites. Various air filters help clean the air you breathe.

Air filtration is an essential function to improve indoor air quality. Indoor air quality is essentially a measurement of the pollutants that can cause adverse health effects and discomfort in building occupants. Air filtration is the most common remediation method for indoor air quality problems.

Indoor air quality may be adversely affected by particulate contaminants and gases. Tobacco and cooking smoke are the most common particulate contaminants that affect indoor air quality. Other particulates include common household dust, pollens, VOCs (volatile organic compounds, offgassing from chemicals used in the house, finishes, and some building materials) and dust from lead-based paint. Gaseous contaminants include carbon monoxide and radon, a radioactive gas found most often in basements and other areas in close contact with contaminated ground and are closed up tight.

Air filtration remediation of indoor air quality problems begins at the intake points throughout a building. Air filters are commonly installed at the intake ports of heating, ventilating, and air conditioning systems (HVAC systems). These air filters remove mostly particulate contaminants. They are rated according to the fineness of particulates that they are able to remove. A HEPA (High Efficiency Particulate Air) filter is recommended; this type of filter is used in hospitals.

Of course, not all points at which air enters a building can be guarded by air filtration systems. Particulate contaminants also arise within the home, past the barriers erected by point-of-entry air filtration systems. So indoor air filters may be installed in interior ventilation ductwork, or in rooms throughout a building. These air filtration systems trap household dust, particularly the droppings and skin sheddings of house mites, pollen, tobacco, cooking, and fireplace smoke, and other particulates generated in the room or admitted via doors, windows, and other gaps in the room’s perimeter.

Mechanical air filtration systems may employ fine screens or meshes to trap particles, or an electrostatic field that pulls particles out of the air and adheres them to a metal plate that can be removed and washed clean.

Activated charcoal air filtration systems can remove gases from the air. The tiny pores in the surface of very fine activated charcoal grains trap the gas molecules. While the trapped gas molecules can be released by heating the activated charcoal, it is unwise to "re-charge" the charcoal in this way because one is simply releasing the contaminants back into the atmosphere. Replacing the activated charcoal filter unit occasionally is the recommended procedure.

Indoor air quality is very important to human health. Most people spend most of their time indoors, breathing air that may be more polluted than outdoor air. A room tends to trap contaminants and concentrate them. Some pollutants are generated only indoors, such as dust mite particles and cooking smoke.

A number of diseases are caused or aggravated by poor indoor air quality. Allergies are the most common ailments affected by poor indoor air quality, and these conditions are greatly improved by proper air filtration. Asthma, emphysema, and other lung diseases are also exacerbated by poor indoor air quality. Heart disease can be affected adversely by poor indoor air quality.

Even generally healthy people can suffer debilitating headaches, nausea, and irritation of the eyes, nose, and throat from poor indoor air quality. That is why air filtration is essential to maintain adequate indoor air quality.