Improving Your IAQ! Do Air Purifiers Work?
What is your IAQ? IAQ refers to indoor air quality, and in this day with all the pollution and problems associated with allergies and asthma, it's something on most everyone's mind. It's not easy to better your living environment. It seems that everything we do has some effect and using an air purifier is no different.
Most of us know what air purifiers do. They trap and kill bacteria, viruses, large and small particles, pollen, pet dander, dust, dust mites, and more. Do you know that the kind of air purifier you choose can be either harmful or helpful? Some air purifiers produce a heavy oxygen gas called ozone.
Electrically charged plates generate ozone as part of the air purifying process. Ozone in the atmosphere is a protective layer against harmful solar radiation so it is needed and beneficial to our existence on the planet. However, ozone in confined areas can actually have potentially harmful side effects.
This fact leaves many to wonder if air purifiers are a worthy investment. Although it might be best to avoid ozone-producing models, you can benefit from what is often called a "passive" air purifier. A passive design filters the air inside the unit and is usually accomplished using HEPA filters, carbon pre-filters, activated carbon filtration, ultraviolet lighting, antibacterial, and germicidal filters.
Through what is called "active" air purification, the air cleaning process takes place outside of the unit, is usually accomplished through ionization or ozone, and is typically filter free. There are also air purifiers on the market that combine passive and active technology. These units use ion technology along with filters to clean the air.
Active Air Purifiers
Ionizers: Ion technology works in two different ways. First, single charge ionizers - an active technology - generally emits negative ions into the air. The negative ions attach themselves to particles. Second, electrostatic precipitators and charged media filters trap particles on electrostatic plates and change their chemistry.
The problem with this system is that too many ions in the air create an imbalance that can be harmful. This form of air purification produces some ozone, so if this concerns you, passive technology is the safer option.
Ozone generators: This form of air purification is considered effective by some, but it is also controversial. Ozone is a molecule composed of three atoms of oxygen. The third oxygen atom can detach from the ozone molecule, reattach to molecules of other substances, and alter their composition. Because ozone is an oxidizer, it works great on microorganisms like mold, mildew, bacteria, VOCs, and gases.
However, organizations like the FDA, OSHA, and NIOSH have recommended that exposure to ozone be limited. The EPA's National Ambient Air Quality Standard for ozone is a maximum 8 hour average outdoor concentration of 0.08 ppm or parts per million. The FDA requires ozone output of indoor medical devices to be no more than 0.05 ppm.
The jury is out on whether ozone-producing purifiers are completely effective. It's believed that ozone alone can clean the air; however, when it meets other chemicals like new carpet odors and the like, it's thought to produce aldehydes.
The EPA distinguishes the presence of ozone as "good up high" and "bad nearby." In other words, ozone in the upper atmosphere is good as it filters damaging ultraviolet radiation from the sun." Ozone in the atmosphere, which is the air we breathe, can be harmful to the respiratory system. This type of ozone usually contains high concentrations of nitrogen, fine particles, and hydrocarbons.
HEPA filters: A HEPA filter traps particles as they move through the filtering system. A HEPA filter removes pet allergens from 0.3-100microns, dust and dust mite allergens from 10-40 microns, pollen 10-100 microns, plant spores from 10-70 microns, airborne fungi spores from 0.5-5 microns, mold spores from 2-20 microns, and tobacco smoke from 0.003-0.04 microns.
A HEPA filter doesn't remove odors, chemicals, or gases. It does remove 99.97% of airborne particles. It does work with the filters described below to provide the best possible results. Some HEPA filters are treated with antimicrobial agents to control the growth of bacteria, viruses, and mold.
Carbon pre-filter: This filter maximizes the effectiveness of the HEPA filter. It captures large particles like pet dander, dust, and odors. Without a pre-filter, the HEPA filter would get clogged.
UV light: UV filtration is a disinfection method that kills microorganisms. It's primarily used to kill pathogens, viruses, and molds that are airborne or growing on surfaces.
TiO2 filter: TiO2 filters work with the UV light to target and render bacteria and other contaminants harmless. Together, these filters attach themselves to harmful airborne compounds and burn off off ending pollutants by turning them into nothing more than harmless carbon dioxide and water molecules.
VOC filter: A VOC filter or activated carbon and charcoal filter combats volatile organic compounds or harmful VOCs. These carbon-based airborne and sometimes odorous chemicals commonly found throughout the house in items like paint, furniture, and carpeting. The VOC filter targets and removes these particles from the air.
Advanced Passive/Active Technology
Low ozone production: Ionizers and electrostatic technology also known as charged technology features collector plates where particles arecaptured. Negative ions and positively charged electrostatic plates work together to capture particles.
This is an "opposites attract" kind of system. First, the particles are charged with negative ions. As they pass over the plates, they are positively charged. This causes them to stick to the plates. For this reason, the plates must be cleaned on a regular basis.
Both processes produce some ozone. Whether or not it's a risk you want to take is up to you. Ionizers work quickly to spread a negative charge through the indoor air to affect contaminants. They're quieter than filtered units and don't require a constant high rate of airflow.
The drawback is that this type of air purifier doesn't remove contaminants. Eventually, the negative charge fades and the particles float through the air again. Another problem is that negatively charged particles can stick to mucous membranes in the body and possibly trigger allergies.
The dangers include the production of ozone. It's hazardous in large amounts and even though ionizers only create small amounts, it can be dangerous to small animals and anyone with a respiratory condition.
Air circulation: Proper room ventilation is the best way to improve IAQ. Outdoor air is perceivably better than any indoor air. Therefore, acquiring a fan - ceiling or otherwise - along with an open window or door is a great way to improve your indoor air. If this is not plausible, then the EPA recommends that you use passive air purification technology.
So, Do They Work?
The truth is that air purifiers do work. They are known to control allergens and help people with upper respiratory allergies breathe better. Common indoor allergens are cat and dog dander, VOCs, tobacco smoke, dust mite feces, and mold spores. Air purifiers are good for anyone with allergies.
Do they help with asthma? Studies show that an air purifier can help reduce asthma symptoms. The EPA indicates that about 80% of asthma causing airborne particles are filtered through an air purifier; however, some particles, particularly those under 0.3 microns, cannot be filtered.
Do you suffer from COPD and other lung conditions? An air purifier is believed to control the presence of volatile organic compounds orVOCs. At least a portion of the irritants can be controlled, even if complete effectiveness can be limited. For adequate results, you will require an ozone free unit with a pre-filter, UV light, and a micro-filter to capture particles as small as 0.1 microns. When all is said and done, these appliances can be quite beneficial.