The Air Purifier Blogs

With estimated sales of over 4 million units in 1999 in the United States, room air purifiers have become standard appliances in many households and offices. Manufacturers of room air purifiers must strive – harder than anyone else in the air purification industry – to provide low cost products to their consumers. This has resulted in air cleaners with HEPA technology selling for as little as $80.00. While making air cleaning technology affordable is a commendable goal; misleading marketing statements and questionable air cleaning performance have many users disappointed.

This article attempts to draw attention to a number of deceptive marketing practices, that air purifier manufacturers use, which are detrimental to the credibility of the air cleaning industry as a whole.

Since the science of air cleaning is a complex one, finding one’s way through the maze of unsubstantiated claims and misinformation is a difficult task even for the most alert and critical consumer. Seven common industry practices in particular continue to confuse consumers and air cleaning professionals.

1. Theoretical HEPA Efficiency vs. Actual System Efficiency

Due to the high efficiency, reliability and proven track-record, HEPA technology has become the industry standard for particulate filtration in critical environments, such as semi-conductor cleanrooms and hospital operating rooms. Recognizing the great marketing potential of the term “HEPA”, many manufacturers are using it to project a high- performance image onto their room air purifiers. What most HEPA-based air purifiers manufacturers conveniently omit to tell the consumer, is that their air purifiers provide nowhere near the performance level of professional HEPA filter systems used in hospitals and cleanrooms.

Often consumers are misled about an air purifier’s efficiency in removing pollutants. Statements like “effectively removes 99% of all airborne allergens” or “efficiently scrubs the room free of air pollutants”, lead consumers to believe that these air purifiers remove virtually all of the impurities from the air in a normal indoor environment.

Claims about HEPA-based air purifiers often state 99.97% filtration efficiency. In most cases, this is also not true. The actual efficiency, for particles of 0.3 microns or larger, of many HEPA-based air purifiers sold today is below 80%. The “99.97%” refers to, in most cases, the theoretical efficiency rating of the filter paper that is used in the air cleaning device at 0.3 microns or larger.

The performance gap between HEPA-based room air purifiers and professional HEPA filter systems is mainly due to cutting corners in mass-production and profit maximization. There are a number of reasons why most HEPA-based room air purifiers do not achieve actual HEPA performance:

1. HEPA-rated filter media is not used. 2. The HEPA filter media gets damaged during the pleating process (HEPA media breaks easily). 3. There is leakage between the pleated HEPA filter pack and the filter frame. 4. There is leakage between the HEPA filter frame and the air purifier housing.

Only very few manufacturers state the actual overall efficiency of their device, and even fewer guarantee and certify their air purifiers.

2. Overstating Actual Air Delivery Rates Even the most efficient room air purifier in the world would not impact a room’s air quality level, if it were not able to pass enough air through its filters. The amount of air that an air purifier is able to process (air flow rate) is usually expressed in cubic feet per minute (cfm). Consumers are often misled by exaggerated or false claims by manufacturers regarding air flow rates.

One common trade practice is to state the free-flow air handling capacity of the fan motor (i.e. without filters installed), rather than the actual air flow rate (i.e. with all filters installed).

Many manufacturers don’t even make this vital air purifier statistic available to consumers. Instead, many state a suitable room size, without mentioning how many air changes per hour the air purifier would manage to produce in that size room.

Only very few manufacturers state the actual airflow rate of their device (with all filters installed), and even fewer guarantee and certify their air purifier’s air flow rate.

3. ULPA is NOT Better than HEPA In an effort to differentiate air purifiers from the mass of HEPA air purifiers on the market, some manufacturers have introduced air purifiers, which supposedly use ULPA technology. ULPA stands for Ultra Low Penetration Air and is used in modern cleanrooms. The difference between HEPA and ULPA is the efficiency rating of the filter media. Typical HEPA filter media has an efficiency of 99.97% at 0.3 microns, whereas ULPA media has an efficiency rating in excess of 99.999% at 0.12 microns.

Stressing the higher efficiency at smaller particle size, manufacturers of ULPA-based air purifiers claim that these devices are superior to HEPA-based air purifiers. Unfortunately, this is a perfect example where the search for a better sales pitch has resulted in an inferior product, since the reverse tends to be the case. All things being equal, an air purifier that uses ULPA filter media will be less effective in reducing the particle concentration in a typical room, than the same air purifier equipped with HEPA filter media. And as with many HEPA-based air purifiers, many ULPA-based air purifiers come nowhere close to actually delivering 99.999% particle-free air.

While ULPA filter media has the potential to remove more particles than HEPA filter media, that advantage is lost in room air purifiers, due to the reduction of air flow caused by the denser ULPA filter media. ULPA filter media typically allow 20-50% less air to pass than HEPA filter media, resulting in fewer air changes per hour in a given room.

4. Ineffective Gas Phase Filtration In many cases room air purifiers are purchased to deal with gaseous contaminants and odors. So it comes as no surprise that most manufacturers claim to use some technology to reduce gases and odors.

The most common technology adopted by air purifier manufacturers for the removal of gaseous pollutants is activated carbon. While activated carbon in its granular form is unquestionably effective for the removal of many gaseous contaminants, most room air purifiers on the market today use carbon fiber pads, which are only impregnated with activated carbon dust. These filter pads contain only a few ounces of actual activated carbon and as a result, are essentially ineffective for the removal of gases and odors.

Some manufacturers claim that their activated carbon filter eliminates all gaseous pollutants and odors, a feat that is scientifically impossible. Specific gaseous contaminants need specific gas phase filtration technology. Activated carbon does not efficiently adsorb low molecular weight gases. For this reason, special sorbents are needed to effectively deal with pollutants, such as formaldehyde, hydrogen sulfide and ammonia.

Many room air purifiers that use granular activated carbon also use zeolite. Zeolite is a natural mineral, whose pore structure is supposed to be better suited for the removal for gaseous compounds like formaldehyde and ammonia. In fact, there is no reliable scientific evidence to show that zeolite is able to remove any gaseous compound better than specialty impregnated carbons or impregnated alumina. So why is Zeolite used? Zeolite is an inexpensive “filler” that is less expensive than activated carbon. Secondly, the concept of using two different substances to control gases and odors sounds quite promising to the unsuspecting customer.

5. Sacrificing Long-Term Performance While most tests and evaluations of air purifiers assess only air purifier performance during its first few hours of usage, the real test for air cleaning effectiveness is long term performance. Unfortunately, most manufacturers cut costs on features that would enhance long-term performance.

One standard industry practice is the use of ineffective pre- filtration. In HEPA based air purifiers, it causes the HEPA filter to become clogged at a rapid rate. This in turn reduces the air flow rate, thus resulting in fewer air changes per hour in a given room. This is a particularly serious issue, since some manufacturers inform their consumers that their HEPA filters will only need replacing every 3 to 5 years.

Insufficient pre-filtration, also, causes air purifiers with substantial granular activated carbon filters to quickly lose their gas phase adsorption potential. Dust particles – that should be trapped by pre-filtration – clog the miniscule pores of the activated carbon, and destroy its holding capacity to adsorb gases.

Another reason for poor long term performance of air purifiers is that some air cleaning technologies suffer drastic reductions in air cleaning efficiency without regular maintenance or frequent filter change.

Air purifiers with electrostatic precipitator technology experience drastic efficiency reductions as the collector plates become covered with particles. Air purifiers that use electrostatically charged fibers (electrete) also rapidly lose filter efficiency with particulate loading, especially in the presence of tobacco smoke.

6. Frequent and Expensive Filter Replacement While the initial purchase cost for many room air purifiers is relatively low, the cost of replacement filters can be substantial. Here are some reasons why many air cleaners require frequent and expensive filter replacement:

· Lack of effective pre-filters that protect activated carbon and HEPA filters from premature clogging. · Use of small filter cartridges with low holding capacity for pollutants. · Filter replacement instructions that base filter replacement intervals on time passed (e.g. every 6 months) rather than actual usage and degree of air pollution. · Combining several different filter stages in one filter cartridge, thus forcing the user to replace all filters at once, even if only one filter stage is used up.

7. Trying to be All Things to All People While many air purifier manufacturers offer several models, these models often vary only in size, rather than air cleaning technology. And since manufacturers like to have their product appeal to as many potential customers as possible, they sell one and the same unit as the ideal solution for pet allergens, pollen, mold spores, microorganisms, tobacco smoke, odors, traffic fumes and chemicals, etc. In fact, some manufacturers claim that by virtue of using a multitude of filter stages their air purifier is more effective. Unfortunately, the effectiveness of the air purifier suffers, because more filter stages mean higher air resistance and lower air delivery. Air purifiers that only contain filter stages matched to the user’s requirements, offer superior filtration efficiency and air flow.,

Conclusion Industry organizations, like AHAM, have set out to establish some reference point for air purifier performance, they have not succeeded to make comparison shopping for air purifiers a simple task. AHAM’s testing protocols do not evaluate actual particle retention, gas phase filtration or long-term performance of air purifiers.

So what are the lessons when evaluating air purifiers? Don’t believe every claim made by manufacturers. Realize that a $80 air purifier will have serious limitations. Ask manufacturers to substantiate their claims with independent evidence. Check the underlying technology and investigate whether it has been properly implemented. Use tools that allow objective evaluation of air cleaning performance, such as laser particle counters, to check manufacturer’s particulate efficiency claims and evaluate actual particle reduction.

Misleading claims regarding air purifiers and air filters have in the past led to decisions and orders of the Federal Trade Commission against manufacturers, and are likely to do so in the future unless manufacturers practice better self-restraint and self-regulation. Participating in sound business practices and making scientifically proven claims will restore lost faith in room air purifiers, allowing consumers to make informed purchase decisions – based not only on price but, also, on actual performance.

For more than a decade, Americans have been becoming increasingly aware that the air that they breathe in their homes is generally not of good quality. Between cooking and pet odors, mold, mildew, the widespread use of plastic materials, and carcinogenic cleaning products, many feel that their inside air has been compromised. What do consumers do? Purchase an air purifier. In 1998 I was given the gift of an Alpine Living Air Classic machine. It has been touted as an ideal solution for problem air. Let?s see if the product lives up to its billing.

As far as air purifiers go, the Alpine Living Air Classic [now sold by EcoQuest International] is neither cheap nor does it look cheap. Weighing 19 pounds, the “Classic” is housed in a wooden cabinet available to consumers in four colors: dark walnut, light oak, putty, and black. It is a solid unit with a thick six foot electrical cord. Claiming coverage of up to 3,000 square feet most homes could operate with just one unit although a second one might be needed if your house is large, indoor air pollution is high, or you have high humidity. Prices currently start at $549 so it is no cheap investment.

How does it work? The unit produces ozone which coupled with an active fan it reproduces and spreads the clean, fresh scent of a thunderstorm throughout your home. Okay, I am parroting some of the marketing material…I had to because it isn?t that easy to describe.

So, does it work? As far as producing the “thunderstorm scent” it certainly does. As far as getting rid of pollutants, odors, and the like I cannot tell you for sure that it does. Indeed there has been plenty of controversy and government rulings against the reported claims of air purifiers over the years by the U.S. Environmental Protection Agency {EPA}, Consumer?s Union [they produce Consumer?s Report magazine], and the American Lung Association.

The EPA has this to say, “whether in its pure form or mixed with other chemicals, ozone can be harmful to health. When inhaled, ozone can damage the lungs. Relatively low amounts of ozone can cause chest pain, coughing, shortness of breath and, throat irritation. It may also worsen chronic respiratory diseases such as asthma as well as compromise the ability of the body to fight respiratory infections. They go on to say, some studies show that ozone concentrations produced by ozone generators can exceed health standards even when one follows manufacturer’s instructions. Many factors affect ozone concentrations including the amount of ozone produced by the machine(s), the size of the indoor space, the amount of material in the room with which ozone reacts, the outdoor ozone concentration, and the amount of ventilation. These factors make it difficult to control the ozone concentration in all circumstances.

In conclusion, the EPA states: Available scientific evidence shows that, at concentrations that do not exceed public health standards, ozone is generally ineffective in controlling indoor air pollution. The concentration of ozone would have to greatly exceed health standards to be effective in removing most indoor air contaminants. In the process of reacting with chemicals indoors, ozone can produce other chemicals that themselves can be irritating and corrosive.

As you can imagine, I no longer use my Alpine Living Air Classic. It sits in my office, unplugged, and working well in its new role as a coffee cup holder while I work on my computer. Frankly, the claims made against this unit made by the federal government and others are certainly frightening.

So, how do I achieve clean air today? Again, by visiting the EPA’s site I have learned that there are 3 common approaches to reducing indoor air pollution:

Source Control: Eliminate or control the sources of pollution;

Ventilation: Dilute and exhaust pollutants through outdoor air ventilation, and

Air Cleaning: Remove pollutants through proven air cleaning methods.

Of the three, the first approach — source control — is the most effective. This involves minimizing the use of products and materials that cause indoor pollution, employing good hygiene practices to minimize biological contaminants (including the control of humidity and moisture, and occasional cleaning and disinfection of wet or moist surfaces), and using good housekeeping practices to control particles.

The second approach — outdoor air ventilation — is also effective and commonly employed. Ventilation methods include installing an exhaust fan close to the source of contaminants, increasing outdoor air flows in mechanical ventilation systems, and opening windows, especially when pollutant sources are in use.

The third approach — air cleaning — is not generally regarded as sufficient in itself, but is sometimes used to supplement source control and ventilation. Air filters, electronic particle air cleaners and ionizers are often used to remove airborne particles, and gas adsorbing material is sometimes used to remove gaseous contaminants when source control and ventilation are inadequate.

If you are intent on purchasing any air purifier, I recommend that you first do plenty of independent research apart from what the marketers tell you. By following the 3 methods stressed by the EPA you should be able to achieve acceptable indoor cleanliness without resorting to purchasing expensive – even dangerous – air sanitization equipment.

The sale of air purifiers across the United States has skyrocketed over the past few years. With research showing that indoor air pollution is 2 to 10 times more than outdoor pollution, there are valid reasons for people to get worried. The only option they now have to deal with the pollution is to install air purifiers in their homes.

Air purifiers are mainly of two variants – the ionic air purifier and the HEPA air purifier. The technology in the two are different and so is the method they work. An ionic air purifier just draws the neutrally charged particulates to the charged plates inside the purifier. This technology ensures that there is little or no sound during the cleansing process.

A HEPA air purifier works on a completely different principle where a filter is used to collect pollutants from the air. To do so a fan revolves at high speed to draw in the air form the room and the pollutants floating in the air gets deposited on the filter. The HEPA filters are effective for particulates as small as 0.3 microns. It would make sense here to pint out that the width of human hair is about 100 microns.

However there is a drawback to the HEPA air purifier. While at work the HEPA ones actually produce some sound which can be annoying for many. The sound is produced because of the fan inside revolving at high speed. While for some it would not be too much of a bother, and some even may actually like the white noise produced, there would be individuals who will hate a constant buzzing sound.

When you are buying an air purifier you expecting some clean air, and not a gadget which produces inconsistent noise. You can obviously do something to tackle this problem. When we buy air purifiers we take a note of our room size. Now, if we buy a purifier which just has the capacity to clean our room then we must have it working to its utmost. This means that fan will always be revolving at the highest speed. The result would be the noise.

However, if we take a purifier with the capacity of cleaning a 800 square feet room for a room of size 200 square feet, then we can always have the fan inside the purifier work at low or medium levels. This will result in less noise. The purifier, all of a sudden will sound quieter. The only thing that would be of concern is the size of the purifier might be too big for the room.

Because of allergies and asthma I’ve owned over 56 air purifiers since 1974. And I even became a Health
Practitioner in 1982 because of the way I overcame allergies and asthma naturally.

I’ve owned: Ozone air purifiers, Ionic air purifiers, Zeolite, HEPA air purifiers, UV light, Catalytic plate air purifiers, water air purifiers, etc..

Brand names I have owned – Alpine Air, EcoQuest, Hunter, Panasonic, Austin, IQair, SunAir, and about 23 other “non-name” Chinese brands. (I avoided Sharper Image and Oreck because ionic alone just doesn’t do enough for me.)

So I’ll just say I have seen it all.

Last year Austin, IQAIR, Oreck and Sharper Image (their new models, not ionic breeze) made me an offer to distribute their products. I said no.

Here are the three major reasons why the major brands have problems:

The No Replacement Filter Air Purifiers Don’t Do a Great Job

The idea sounds great but once you’ve seen a dirty HEPA filter (HEPA’s are a cloth-like filter which holds dust and pollution) you realize the ones without filters aren’t catching very much dust or pollen – YOUR LUNGS ARE!

“No Replacement Filter Models” include:

Ionic Breeze

Oreck (they contradict themselves on their website. You have to replace filters, but they aren’t HEPA)

Remedy – Get an air purifier that has affordable replacements. HEPA is important if you have allergies.

Most Replacement Filters (HEPA, Charcoal) are Over-Priced

In Japan air purifiers include 2-3 extra replacement filters. WHY? Because the Japanese think ahead.

U.S. manufacturers realize American’s don’t think ahead so they overcharge. Once you purchase an air purifier you’ll be stuck paying what they ask. (Reminds me of my $89 inkjet printer –the replacement cartridges are $28!)

Remedy: Ask for filter prices first. Every 6-12 months you’ll need to change filters. And anything over $25 is too much.

Buying Hint: Ask for a discount on extra replacement filters before buying.

Most Air Purifiers Won’t Do The Square Footage On The Box

I called Oreck when their new $700 tower was listed as covering 1100 square feet. “How Many Times Does It Change The Air In The Room?” (which means how many times it will change all the air in that room). They didn’t know. Finally a tech said: “One per hour”. That’s poor.

Remedy: Make sure to ask for 4-9 “Changes Per Hour” per Square footage.(You may have to call the manufacturer) Square Footage as listed on the box is also based on an empty room.

How to Choose The Right Technology

Here are some guidelines to match the basic technologies to your needs:

#1 HEPA, Pre-filter, Neg/Ion, Plasma Grid = Helpful for allergies and asthma, some odors

#2 Carbon, Charcoal, Ozone = Helpful for odors, smoke, animal smells, chemical sensitivity, VCO’s, and immune system
#3 UV, TiO2, Plasma Grid, Ceramic = Helpful for immune system (colds, flu, viruses, pathogens), and eliminating musty odors

New Sensor Technology There is a cool new technology from Japan that detects pollen. It promises to bring greater allergy relief. It continuously adjusts the purifier to the room saving electricity and guesswork.

CONCLUSION: Look for an air purifier that has HEPA, and 3-5 additional technologies such as UV and ion. Keep away from infomercial brands as the markup is high. Expect to pay $250-350 (and don’t pay more). Make sure the replacement filters are reasonably priced.