Air Purifiers
Another aspect to maintaining a comfortable atmosphere in the home is the purity of the air you are breathing. Air purifiers can improve the air quality immensely.
This is especially so if your home's atmosphere is generally dusty or in some way polluted with airborne pathogens, pollen, mold spores, chemicals, smoke, odors etc.
If you or a family member suffers from allergies or has respiratory problems, it would be wise to employ an air purifier to remove much of the irritants that can be floating about in the air that you may not be able to see or even smell!
Let's look at the function of air purifiers and see how they work and how they can be of benefit in the home for improving indoor air quality.
Making the Decision
It is not easy to decide whether you want an air purifier in your home.
It must be running 24 hours a days to be effective. This can increase your energy bills by anywhere from $50 to $150 per year depending on which model you choose.
Add in the cost of filters and the initial cost of the unit, and you can end up spending as much as $500 per year. Does having cleaner air offset this cost with value? It all depends on how clean the air is in your home.
Depending on the model of the purifier, it can remove particulate matter and VOCs (Volatile Organic Compounds) from the air you inhale. Some units can even handle all three.
An air purifier is most beneficial for people with allergies or respiratory conditions like COPD or emphysema. However, it can also be used by sensitive individuals who are allergic to VOCs, residual smoke from cigarettes or wildfires or are otherwise affected by VOCs.
Although an air purifier cannot replace fresh air from an open window or filter, it can be a lifesaver when the air becomes polluted from nearby fires, for example.
HEPA Filter
Most commercially available air purifiers include a HEPA (High-Efficiency Particulate Absorbing) filter. This can remove particles larger than a few microns.
VOCs and odors can be removed by carbon filtration. Some models include HEPA or carbon filtration with ultraviolet radiation. This kills pathogens.
Some people create charged particles or ions to attract pollutants and make them disappear from the air.
Photo electrochemical oxidation, the most recent purification technology, produces free radicals which oxidize VOCs, moldspores, and bacteria and render them inert. Air purifiers often combine multiple purification methods.
How Air Filtering Works
HEPA filters were created by the U.S. military for use in gas masks during World War II. HEPA filters are made up of layers of glass-like paper in V shapes, separated by sheets corrugated aluminum.
A fan blows ambient air through an HEPA filter with a minimum efficiency reporting value (MERV) of 16-18. Pollutants stick to the filter material and emergent air is clean of particles larger that 0.3 microns.
High-efficiency HEPA filters can catch bacteria. However, the pollutants eventually block the filter and it can't be cleaned. Therefore, the filter must be replaced at regular intervals.
A HEPA filter by itself won't remove all VOCs and odor-causing pollutants. Many air filtration systems include a carbon filter.
This filter absorbs compounds like formaldehyde and benzene from upholstery fabrics, paints, adhesives, and pressed wood furniture.
Air Filtration Systems Are Different to Air Purifiers.
Although filters can remove pathogens from the atmosphere, they do not kill them. The pathogens that collect on filters can end up circulating through the air.
To keep the air moving through the filter, a fan must be running continuously. These fans can be loud and require a lot of energy.
This is in addition to other appliances running such as air conditioning or heating, depending on the time of year.
Ultraviolet Air Purification
The sun emits ultraviolet radiation in all directions, but the earth's atmosphere is able to filter out the most dangerous.
The radiation known as UV-C damages cells by damaging nucleic acids and disrupting their DNA. This principle is used by UV air purifiers.
A UV air purifier is able to kill pathogens by using a combination of a HEPA filter and an internal lamp that emits harmful radiation. The radiation-proof enclosure houses the lamp so that no one is exposed.
Ionization Air Purifiers
Since the 1990s, ionization air purifiers are available. They can be used with or without HEPA filters. One of two methods is used.
The first is a pair oppositely charged electrostatic plates that create an electric field which charges particles passing between them. The charged particles form in the air and settle on the plates. They must be removed from the plates every so often.
Although electrostatic precipitators are capable of removing some of the most dangerous and small particles, they also produce ozone which can be harmful to people with breathing problems.
The second type of ionization purifier emits a stream containing negatively charged ions. These ions accumulate on pollutants and cause them to weigh more and settle out of the atmosphere.
This method is not only dangerous, but it also produces ozone. The particles stick to furniture, carpets, and your lungs electrostatically. People with respiratory conditions or allergies will not find this a suitable solution.
PECO: A New Air Purifying Technology
NASA developed PECO (Photo Electrochemical oxidation) as an air purification technology.
This technology uses models to generate UV-A radiation. It is the most energetic and least harmful type of ultraviolet radiation.
The UV-A radiation is used to ignite a nanocatalyst, and then initiate an oxidative chemical process on its surface. This reaction removes impurities in the air.
PECO technology is very similar to the Photocatalytic Oxidation (PCO) technology used in other ultraviolet air purifiers. PECO technology does not produce ozone, formaldehyde, or other pollutants that are byproducts from PCO systems. Instead, it uses UV-A radiation.
PECO Air Purifiers are sold by a company that claims their products are the best on the market. The electric blowers are quiet and low-demand, and consume about the same power as an incandescent bulb.
Your Needs and Budget Dictates Your Choice
A purifier can cost anywhere from $150 to $800. Even if you buy an Energy Star rated model as recommended by the EPA, it will cost you about the same amount to run as a similar rated refrigerator.
Although they have some drawbacks, air purifiers can also be beneficial for those with respiratory issues and allergies.
Be aware that an air purifier is not a house-wide appliance. The purifier is designed to clean air in the one room that it occupies. The size of the appliance will depend on how large the space is.
Remember to use an air purifier in conjunction with good cleaning habits.
An air purifier by itself won't make your home smell good if the source of the smell is not addressed, although a HEPA filter can help with allergies. It also won't fix a mold problem if the source of the mold is not eradicated, so always be sure your home is cleaned regularly and thoroughly.
Published Titles
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