Become an Appliance Expert. Subscribe to our Knowledge Base!
The Many Benefits of an Air Purifier
The plethora of air purifiers available on the market today can leave consumers feeling bewildered. As many as fourteen air-purifying techniques exist, each using unique and distinct technologies designed to clean the air you breathe, leaving buyers somewhat spoiled for choice.
Many of you will ask: who says my air is dirty? Isn't the air indoors cleaner than the air outside? The Environmental Protection Agency's answers may shock you. Consider your own daily routine, and how much of your time you spend inside your home or office. A study in the USA concluded that Americans spent on average around 90% of their time indoors, so it is important to understand the steps you can take to ensure that the air you breathe isn't harming your health. Furthermore, which types of air purifiers are appropriate for removing different contaminants?
Air purifiers all work on a common principle: they process the air around them, remove the contaminants, and then release clean air for us to breathe. But what are these contaminants, and how have they gotten into your home?
Common harmful particles in indoor environments include dust, moisture and mold, allergens such as pollen, secondhand smoke, pet dander, as well as asbestos and radon gas. In addition, you invite outside fumes and pollutants into your home each time you open a door or window. These harmful particulates are then trapped inside with you and will become part of the air that you and your family breathe.
Consider the natural carbon cycle: you breathe in oxygen and breathe out carbon dioxide, which in turn is used in photosynthesis in trees and plants and converted into clean oxygen once more. In a confined space, however, the carbon dioxide has nowhere to go and so the confined environment's carbon dioxide level becomes increasingly concentrated. The same concept applies within your home. Any harmful elements in the air have nowhere to escape - so you breathe them in.
Solutions to Poor Air-Quality
Air purifiers are one solution to this air-quality problem. An alternative would be to keep your windows and doors open to allow for total ventilation - but this is impractical. So in this age of energy-efficient airtight buildings, air purifiers have become an essential accessory for many homes and businesses.
Generally speaking, the best ways to reduce the risk of contaminants in the air are simple common-sense measures to combat the main sources of pollutants. Vacuum and dust regularly, smoke outside, keep hygienic care of yourself and your pets, and maintain a sensible temperature.
An air purifier can help to augment these measures and, depending on your specific needs, they can help you to maintain a healthy atmosphere so clean that even the most cleanliness-obsessed hypochondriac won't be able to find fault with it. Various models of air purifiers are available, and each utilizes different methods specific to its individual purpose; some are ideal for removing smells from bathroom odors and pet dander, whilst others will be designed specifically to combat the more harmful chemical particles in the air. Other factors to consider when mulling over an air-purity-related purchase relate to the machine itself: Is it large and cumbersome? Does it produce unwanted noise? Does it fit the d??cor of my home?
Do I Actually Need an Air Purifier or Is That Just a Myth?
A quick Web search on the subject of air purity indoors will leave you tangled in a veritable overload of information, much of it speculative conjecture. With some patience, however, it is possible to sort the nonsense from the facts, behaving in much the same way as our chief protagonist, the air purifier.
A 2009 American study identified an astonishing 586 individual airborne substances in 52 homes in Arizona, which highlights how easy it is for unexpected contaminants to become present in the atmosphere in the home. Another striking conclusion drawn by the investigation was that children and babies are the most at risk. This is because the air less than two feet from the ground is the most concentrated in terms of contaminants, which are denser than air and therefore sink lower towards the ground.
Pure Air: A comparison
On the journey to air-purity enlightenment, you may be wondering which air purifiers have significant medical benefits - and how can this device protect you against the invisible microscopic onslaught?
HEPA (High Efficiency Particulate Air)
The simplest air purifiers work on a straightforward filtering system much like those found in other appliances such as vacuum cleaners and tumble dryers. Based on size-exclusion, the filter will prevent particles of a certain size from passing through. The most scientifically endorsed of these are HEPA (High Efficiency Particulate Air) filters, which remove 99.97% of airborne particles as tiny as 0.3 microns in diameter.
|What is a micron? Micron is short for micrometer. There are one million micrometers in a meter and 25,000 in an inch!|
To put it into context, that's one-fiftieth the width of a silk fiber (15 microns). According to The Physics Factbook a human hair ranges from 17-181 microns. The frightening conclusion drawn by medical researchers is that airborne particulates as small as 0.3 microns can be ingested through breathing. More worrisome still is the fact that these nanoparticle pollutants can be deposited and build up in our respiratory systems and potentially cause long-term damage in the same way as asbestos. HEPA filters will remove all manner of microscopic miscreants from the air including dust, pollen, and mold spores but it will do little or nothing to remove tobacco smoke or household odors. Users must remember to periodically replace the filters in order to keep the purifier working. Some filters are washable, but as they tend to be made from synthetic fibers, such as fiberglass, this is not always the case.
These filters are trusted in the medical industry as well; HEPA filters are fitted in personal respirators worn by doctors, protecting them against contagions when dealing with patients infected with tuberculosis.
UVGI (ultraviolet germicidal irradiation)
A less passive choice may be a device which uses UV light to sterilize the air you breathe. Usually accompanied by an intake fan, these purifiers suck in air and then bombard it with invisible ultraviolet rays, which will kill or render inactive the harmful organisms in the air. The larger the particle, the longer it will need to be exposed to the UV light, which can allow smaller particles to slip through in a process known as ???shadowing.' UV bulbs also lose effectiveness over time without necessarily burning out visibly, so from a consumer perspective it can be troublesome to know when to replace the bulbs.
These purifiers ionize atoms through a process called corona discharge. In simplified terms, it operates like a giant magnet sifting through the air: neutral atoms pass through the purifier's electric field and will either lose an electron (and become a positive ion) or will gain an electron (to become a negative ion). These charged particles will become attracted to collection plates within the device and are thereby removed from the air. Another variation of this technology simply generates charged ions, which attach themselves to airborne particulates, which in turn become heavy and sink onto surfaces.
Ionizers, fitted with an intake fan, clean and distribute air at a much quicker rate, but also produce more unwanted noise. One drawback associated with this method of air purification is ???black wall syndrome.' This phenomenon occurs when the charged particles are attracted together and collide to form larger particles, which are then deposited on surfaces nearby the ionizer. This often results in a soot-like substance coating the wall to which the ionizer is affixed.
Ozone generators focus on the biological contaminants in the air such as bacteria. The concept is that the device will disinfect the air - and deodorize it as well. These are targeted at the industrial industry, however, and the Environmental Protection Agency in the USA recommends against home use. They are used in homes by professionals, to combat significant mold damage or decay, which leaves an otherwise irremovable odor. Ozone air purifiers for the home do exist but their practicality is questionable. They are designed to convert oxygen molecules into ozone, which in turn sterilizes the air before reforming as oxygen. This is potentially hazardous as ozone is a toxic gas in high quantities in a confined space. Even more problematic is the potential for byproducts when using these devices - the process of converting oxygen to ozone also produces nitrogen oxides, the gases found in acid rain.
Some air purifiers rely on a process of adsorption (not absorption) to remove contaminants from the air. Adsorption is the adhesion of a thin layer of molecules to the surfaces with which they are in contact. An extremely porous radioactive compound traps passing molecules; activated carbon is usually used, because of its extremely large surface area (on a molecular level). The gaseous molecules are converted to solids and become bonded to the surface of the carbon.
Usually this concept is used in conjunction with other filter-type purifiers such as HEPA, and like any filter it will need replacing once its entire surface has been used up.
Thermodynamic Sterilization System (TSS)
These purifiers draw on several of the concepts we've already explored; air is sterilized by a heating element, usually a ceramic core, at temperatures of 200°C (392°F), effectively incinerating 99.9% of harmful particles.
The air is then cooled via heat transfer plates and released at room temperature, free from contamination.
Making a Purchase: Factors to Consider
First of all, as with any purchase, you want to get your money's worth, and research can help make the right choice for you. Air purifiers are all different, as we've already discovered.
Some devices are better for removing bacteria, others will primarily cleanse your home of unpleasant smells, and some are more versatile and fall somewhere in between the two. It's important, therefore, to know what you want in advance. Are you concerned about the impact of atmospheric pollution on your health? Do you have a mold issue? Do you have allergies? Are your pet's odors lingering?
Another important thing to consider is the physical make-up of the product. Consider its size, weight, even its color. How would it look in your home? Where would you put it for optimum impact - will it be in the way? Many people will be put off making a purchase by the idea of introducing a large whirring piece of machinery to their homes - but these products are available in compact, discrete designs, such as the unobtrusive Luma Comfort AP170W air purifier. Noise level is another consideration. Bedrooms should have a quieter model, while living areas can afford to have a slightly more aggressive sound to it.
What if I have asthma?
If you have allergies or asthma, it can be difficult to keep this under control particularly if you have pets or children. You should always consider carefully how an air purifier could help alleviate your symptoms.
Asthma UK offers several measures for reducing the number of asthma 'triggers' that you expose yourself to, such as purchasing hypoallergenic bedding, having hardwood floors instead of carpet, or dehumidifying the air to kill dust mites. If you are a meticulous clean freak you won't balk at the advice to freeze soft toys every few weeks to kill dust mites, but the vast majority of people turn to air purifiers because they are seeking a more practical solution for reducing asthma and allergy catalysts.
An air purifier won't be a magical solution to any problem, but it can improve the quality of the air you breathe, whether you have asthma or allergies or both - or neither! The dust, pet dander, and other tiny airborne irritants that can set off a coughing fit are not a necessary evil in your home. Sensible measures such as regular dusting and vacuuming will greatly improve air quality and an air purifier can greatly augment this by eliminating whatever small amount of dust or contaminants that escapes your attention.
The conclusion of a study conducted by the US National Institute of Health supports this: "Air filtration is frequently recommended as a component of environmental control practices for patients with allergic respiratory disease. Studies support multiple interventions, including air filtration, as methods to improve outcomes in the treatment of allergic respiratory diseases."