Factors to Consider When Buying an Air Purifier

Know what to look for and how to find the air purifier that best fits your needs.

 

 

What pollutants does it remove? And how good is it at removing them?

 

This is normally the first question you should ask when buying an air purifier. Since there is no single air-cleaning technology that is proficient in neutralizing all common pollutant types, you should look for a model that offers multiple ways of purifying the air. But still, every case is different. Most people begin their search with a specific issue to resolve, whether it be allergies, odors, cigarette smoke or mold and mildew. Even among multi-function units, not all air purifiers are created equal, especially when it comes to addressing any one particular issue. Some will solve your primary problem better than others.

With this in mind, let's examine the different airborne pollutant categories, and what you should look for in eradicating each:


Problem: Dust, pollen, dander, mites, mold spores and other allergens and particulate

If you are suffering the effects of allergies or asthma--such as sneezing, wheezing, coughing, runny nose or itchy eyes--then the air in your home or office is likely teeming with these allergenic culprits. They're too small to see with the naked eye, which means they're also small enough to remain airborne, swarming into your lungs and nasal passages with every breath you take. If the dust is always building up faster than you can clean it, if you can see little flakes floating in the sunlight that comes through the window (most of which is dead human skin), if there are pets running around, if the trees outside are blooming, if you have pockets of high humidity inside (great breeding ground for dust mites and mold), microscopic allergens almost certainly abound.

Once you establish that you have a dust and allergen problem, any allergist would recommend that you get an air purifier. But which one?

Best Solution for Dust and Allergens: HEPA Filter

Every objective expert agrees that when it comes to removing microscopic particles from the air, nothing works better than a HEPA filter. HEPA filters were developed by the Atomic Energy Commission during World War II to remove radioactive dust from their plants. HEPA filters are made from highly fibrous and highly absorbent material, capturing 99.97% of particles at 0.3 microns in size, which is 300 times smaller than the diameter of a strand of human hair. HEPA filters will capture particles much bigger and smaller than this, but they are tested at 0.3 microns, since this is the most penetrating particle size. In other words, it is the particle size most likely to have both the mass and size to penetrate through a filter and deep into the lungs. (About HEPA Air Filtration)

What to look for in a HEPA filter:

  • Make sure it is a "True" HEPA filter, and not just "HEPA-like". All Surround Air purifiers include a True HEPA filter.
  • Make sure the HEPA air purifier comes with a germicidal UV lamp, otherwise, your HEPA filter could become a breeding ground for microbes with all the particulate it will capture. All Surround Air purifiers include a UV lamp as well.
  • Make sure the air purifier has strong air flow. Somewhere between 100 and 200 cfm is ideal. If it is lower than this, it will be effective for smaller spaces. If it is too high, it will be far too noisy to tolerate, while also consuming far too much electricity. Plus, if it is too high, it can push the air past the UV lamp too quickly to be properly disinfected.
  • Replacement costs. Know how much it will cost to replace the HEPA filter before you buy.
  • If possible, find a HEPA filter that comes with an ionizer. A Journal of Hygiene study found that negative ions increase the efficiency of HEPA filters. Almost every Surround Air purifier includes an ionizer.
  • Permanent or Cleanable versus Disposable. Most HEPA filters will last about a year before needing to be replaced. But there are permanent/cleanable HEPA filters designed to last the life of the unit. Ideally, even "permanent" HEPA filters should be replaced every 2-3 years, for optimal effectiveness. You may not get quite the same effectiveness as a HEPA that is replaced annually, but it will provide you the convenience and cost-savings of a longer-lasting filter. The Intelli-Pro 3 model comes with a cleanable HEPA filter.
  • Pre-filter. Although not a necessity, a pre-filter can prolong the life of a HEPA filter.
  • An electrostatic dust collector will also help to remove dust and particulate, which is attracted to the magnetically-charged plates. Simply wipe clean as needed. The following Surround Air models come with both a HEPA and electrostatic dust collector grid: Intelli-Pro and Multi-Tech 2000.

Recommended Surround Air model # 1 for allergens/dust: Intelli-Pro XJ-3800.

  • True HEPA Filter.
  • Includes germicidal UV lamp and ionizer.
  • Also comes with a photocatalytic oxidation filter and an activated carbon filter for chemicals and odors.
  • Sensor technology to monitor filter life and filter performance. Filter indicator alerts when it is time to change the filter.
  • Includes an Electrostatic Precipitator (Dust Collector Grid), which have also been proven effective at capturing dust and allergens.
  • Includes "Auto" mode, which adjusts fan speed according to pollution level (detected by pollutant sensors).
  • Includes advanced sensor technology to let you know if dust and allergens are present, along with the degree of severity.
  • HEPA/carbon combination filter lasts about one year, and costs just $36 to replace.
  • Strong air flow, but not too strong to compromise the effectiveness of the Electrostatic Precipitator and UV Lamp: 106 cfm.
  • $189 with free shipping.

Recommended Surround Air model # 2 for allergens/dust: Intelli-Pro 3.

  • True HEPA Filter.
  • Includes germicidal UV technology and ionizer.
  • Also comes with a photocatalytic oxidation filter and an activated carbon filter for chemicals and odors.
  • Sensor technology to monitor filter life and filter performance. Filter indicator alerts when it is time to change the filter.
  • Includes "Auto" mode, which adjusts fan speed according to pollution level (detected by pollutant sensors).
  • HEPA/carbon combination filter lasts about one year, and costs just $44 to replace.
  • Very strong air flow to maximize air-flow exchanges, boosting air-cleaning efficiency: 180 cfm.
  • $159 with free shipping.

Recommended Surround Air model # 3 for allergens/dust: Multi-Tech 8500.

  • Professional-grade True HEPA filter, made from material that is more fibrous and absorbent than what is typical.
  • Includes germicidal UV lamp and ionizer.
  • Also comes with a photocatalytic oxidation filter and an activated carbon filter for chemicals and odors.
  • Sensor technology to monitor filter life and filter performance. Filter indicator alerts when it is time to change the filter.
  • Includes "Auto" mode, which adjusts fan speed according to pollution level (detected by pollutant sensors).
  • HEPA/carbon combination filter lasts about one year, and costs just $36 to replace.
  • Strong air flow: 135 cfm.
  • $129 with free shipping.

Problem: Cigarette Smoke

This is perhaps the most obvious of all indoor air quality problems. The smell is unmistakable, and often, the residue is readily visible as well. Cigarette smoke presents a three-pronged indoor air quality challenge. First, you must remove the smoke particulate itself. But it doesn't stop there. To protect your health, you must tackle the chemical vapors as well. And finally, there is the pungent odor to contend with.

Best Solution for Cigarette Smoke: Activated Carbon + Ionizer + Photocatalytic Oxidation or Programmable Sanitizer

An activated carbon filter and ionization is a must when dealing with cigarette smoke. Activated carbon is the most adsorbent filter material there is. Even minute chemical vapors are chemically-bonded to its granulated pores. Ionization is effective at settling particulate out of the air, and in enhancing the removal rates of filters. Negative ions can be emitted into the air, to attack airborne pollutants wherever they may be floating within vicinity of the purifier. Photocatalytic oxidation is also effective against chemicals and odors. Perhaps most effective is ozone purification. It is not recommended by to ozonate the air with people present though, which is why the sanitizer should be independently-controllable. It should be able to be turned off when people are present, and turned on when you want to sanitize a room or space. Ozonation is highly effective at oxidizing odor-causing agents, and the ozone will dissipate quickly once it is turned off.

Recommended Surround Air model # 1 for cigarette smoke: Intelli-Pro XJ-3800

  • Includes activated carbon filter and ionizer.
  • Includes Electrostatic Precipitator (Dust Collector Grid), which has also proven effective at trapping smoke particles.
    • Includes Photocatalytic Oxidation filter.
  • Also includes a HEPA filter to help with smoke particles.
  • Includes UV purification to help with odors.
  • HEPA/carbon combination filter lasts about one year, and costs just $36 to replace.
  • $189 with free shipping.

Recommended Surround Air model # 2 for cigarette smoke: Intelli-Pro 3

  • Includes activated carbon filter and ionizer.
  • Includes Photocatalytic Oxidation filter.
  • Also includes HEPA filter and UV purification.
  • Strongest air flow among Surround Air products (180 cfm) to maximize air exchanges and filtration capacity.
  • HEPA/carbon combination filter lasts 1-2 years and costs $44 to replace.
  • $159 with free shipping.

Recommended Surround Air model # 3 for cigarette smoke: Multi-Tech XJ-3000D

  • Includes activated carbon filter and ionizer.
  • Programmable sanitizer with timer. Can be turned on or off as needed.
  • Also includes a HEPA filter to help with smoke particles.
  • Includes UV purification to help with odors.
  • HEPA/carbon combination filter lasts about one year, and costs just $36 to replace.
  • $149 with free shipping.
  • Also consider the Multi-Tech XJ-3000C ($129), which includes all the same features, just a little less powerful.

Problem: Mold and Mildew

Mold is a common problem in humid environments, or where water damage has occurred. Moisture combined with building materials creates an ideal breeding ground for mold. Once mold takes root, it releases allergenic spores and harmful mycotoxins into the air.

Best Solution for Mold and Mildew: HEPA + Ionizer + Germicidal UV

On one hand, mold spores are a particle--a highly allergenic one--and are best captured via HEPA filtration. As discussed above, an ionizer will enhance the effectiveness of the HEPA, while also helping to settle the spores out of the air you breathe on their own accord. On the other hand, the mycotoxins often associated with mold are a microbial pollutant, and cannot be neutralized by a HEPA filter. But they can be destroyed by germicidal ultraviolet light. All Surround Air purifiers include both a HEPA and germicidal UV lamp, while nearly all also include an ionizer.

Recommended Surround Air model # 1 for mold/mildew: Intelli-Pro XJ-3800

  • True Hepa filter with ionizer for mold spores.
  • Electrostatic dust collector grid and ionizer bolster its ability to remove particles such as spores.
  • Germicidal UV lamp to destroy harmful mycotoxins from mold.
  • Also includes a photocatalytic oxidation filter to help with mildew odors.
  • Pollution sensor distinguishes between three types of pollutants: odors, dust and allergens.
  • $189 with free shipping.

Recommended Surround Air model # 2 for mold/mildew: Intelli-Pro 3

  • True Hepa filter ionizer for mold spores.
  • Germicidal UV lamp to destroy harmful mycotoxins from mold.
  • Also includes a photocatalytic oxidation filter to help with mildew odors.
  • Powerful fan to maximize air-flow exchanges, boosting air-cleaning efficiency.
  • $159 with free shipping.

Recommended Surround Air model # 3 for mold/mildew: Multi-Tech 8500

  • Deluxe True HEPA filter for mold spores, more fibrous and absorbent that typical HEPA filters.
  • Includes ionizer to enhance effectiveness against particles such as mold spores.
  • Germicidal UV lamp to destroy harmful mycotoxins from mold.
  • Also includes a photocatalytic oxidation filter to help with mildew odors.
  • $129 with free shipping.

Problem: Strong Odors

Odors are caused by certain chemical compounds, such as VOC's (Volatile Organic Compounds), which can be produced by both synthetic chemicals and bacteria. HEPA filters are of little use against odors.

Best Solution for Odors: Activated Carbon Filter + Programmable Sanitizer or Photocatalytic Oxidation

Activated carbon filters are the most effective type of filter against odor-causing agents, while photocatalytic oxidation is also effective. Ozonation can also be highly effective, using highly reactive ozone molecules to oxidize odor-causing compounds.

Recommended Surround Air model # 1 for strong odors: Multi-Tech XJ-3000D

  • Includes activated carbon filter.
  • Programmable sanitizer with timer. Can be turned on or off as needed.
  • Includes UV purification to help with odors.
  • $199 with free shipping.
  • Also consider the Multi-Tech XJ-3000C ($129), which includes all the same features, just a little less powerful.

Recommended Surround Air model # 2 for strong odors: Intelli-Pro 3

  • Includes activated carbon filter.
  • Includes Photocatalytic Oxidation filter.
  • Also includes germicidal UV lamps to help with odors.
  • Strongest air flow among Surround Air products (180 cfm) to maximize air exchanges and filtration capacity.
  • $159 with free shipping.

Problem: Illness-Causing Viruses and Germs

Especially in the winter, when you are trapped indoors most of the time, viruses and germs can have an adverse effect on your quality of life.

Best Solution for Viruses and Germs

The U.S. Centers of Disease Control (CDC) recommends germicidal UV lamps to destroy micro-organisms. UV light has been proven time and again to be the most effective air-purifying method at destroying germs, viruses and other micro-organisms. The germ-killing "UVC" wavelength radiates UV rays that are deadly against the DNA and protein that sustain micro-organisms.

TIO2 (Photocatalytic) Oxidation Filters have also been proven to be effective at breaking down bacteria.

Recommended Surround Air model # 2 for Germs and Viruses: All Surround Air purifiers include Germicidal UV


Problem: Household Chemicals, Gas Fumes, Pollution from Nearby Roadways or Factory

Indoor chemical exposure is a reality of everyday life for virtually all those who live in the modern world. It comes in both expected and unexpected ways. Even building materials off-gas chemical pollution for years after construction. Almost any manufactured product can be a source of illness, sluggishness, sleeplessness and long-term health problems. Pollution can also come from outside your home, even if you don't live near a factory. According to the EPA, research shows that living within 600 feet of a heavily-traveled road can contribute to a whole host of health problems, including asthma, heart disease and cancer.

Best Solution for Chemical Pollution: Activated Carbon and Photocatalytic Oxidation Filters

Activated carbon is the most effective type of filter against chemicals, fumes and odors. The fiber of activated carbon filters physically bond with these contaminates. Other types of filters, such as HEPA filters, are not effective at removing chemicals from the air.

TIO2 (Photocatalytic) Oxidation Filters have also been proven to be effective at breaking down many types of chemicals.

Recommended Surround Air model # 1 for Chemical Pollution: Intelli-Pro 3

  • Activated Carbon plus large-sized photocatalytic oxidation filter.
  • Strong air flow to maximize air exchanges (180 cfm).
  • $159 with free shipping.

Recommended Surround Air model # 2 for Chemical Pollution: Intelli-Pro XJ-3800-2

  • Activated Carbon plus large-sized photocatalytic oxidation filter.
  • Strong air flow to maximize air exchanges (106 cfm).
  • $189 with free shipping.

Problem: Pet Dander and Odors

If you have a pet with hair, fur or feathers in the home, then you have pet dander. Dander is composed of the microscope flakes of skin that sloughs off of all of your favorite animals. It is also comprised of the animal's saliva, urine and feces. Contrary to common belief, it is not the hair or the feathers or the fur you are allergic to, but rather the dander. Pet dander is more easily aerosolized than dust mites, and can remain airborne for extended periods of time. In the short term, pet dander will worsen allergy and asthma symptoms, and over the long term, it can complicate respiratory conditions and decrease lung function.

Best Solution for Pet Dander and Odors: HEPA + Ionizer + Germicidal UV + Photocatalytic Oxidation

Since pet dander is a particle and an allergen, it is effectively captured by HEPA filters (High Efficiency Particulate Arrestors). HEPA filters are proven to be the most effective air-cleaning method at removing solid particles and allergens. The HEPA's effectiveness is enhanced by the presence of a built-in ionizer, as proven by a Journal of Hygiene study.

Odors are also an issue with pets. Activated carbon filters are the most effective type of filter at removing odor, while TIO2 (Photocatalytic) Oxidation Filters have also been proven to be effective at breaking down odor-causing compounds.

Recommended Surround Air models for Pet Dander and Odors: Multi-Tech 8500, Intelli-Pro 3, Intelli-Pro XJ-3800


Other Factors to Consider

Aside from the types of airborne pollutants you need to remove, you may have other special needs or considerations to take into account. Some of these may be just as important as the ability to remove certain pollutant types. You may have budget or space constraints that are more pressing than performance requirements.It might be more important to have something quiet, or maintenance-free, than an air purifier that is supremely effective.

Below is a list of the most important factors to consider aside from air-cleaning capacity.


Size of Coverage Area

Generally speaking, the higher the fan speed, the larger the space an air purifier is capable of covering. Also, air purifiers with ionizers can cover more space, which disperse air-cleaning negative ions throughout the room. Effective coverage area is also impacted by variables external to the air purifier. The more open the space, the more square footage will be covered. Pre-existing air flow will also help an air purifier to affect a larger area. If the pollution level is higher than typical, the specified coverage area should be adjusted downward, by at least half, if not more.

Recommended Surround Air model for large coverage area requirements: Intelli-Pro 3

  • 180 cfm fan speed (on the highest setting).
  • Includes an ionizer for negative ion dispersal.
  • $159 with free shipping.

Upfront and Replacement Costs

As much as we would all like the best of everything in life, price must always factor in with almost every purchase we make. Most of us cannot afford the most expensive option, but we don't want the cheapest either. We still want strong value: the best balance between price and performance. And with air purifiers, there is the back end cost to consider. It does little good to save money on the initial purchase if the replacement filters are going to bleed your bank account dry.

Recommended Surround Air model for Great Value on a Budget: Multi-Tech 8400 ($99)

  • 5 air-cleaning technologies, including pre-filter, True HEPA, activated carbon, germicidal UV lamp and photocatalytic oxidation filter.
  • With 5 air-cleaning stages, covers just about every category of airborne pollutants.
  • Strong air flow: 135 cfm.
  • Filter change indicator.
  • Spare HEPA/carbon filter lasts about 12 months. Only $29 to replace.
  • Spare UV lamp lasts about 3.5 years. Only $19 to replace.
  • Estimated $35 per year in total replacement costs.
  • Only $99 with free shipping.

Sensor Technology

If you would gladly pay a little extra to know how clean the air really is, and to remind you when to replace the filter, then you should look for sensor technology in an air purifier. Another neat feature with sensor technology is "Auto" mode. In auto mode, the air purifier will automatically adjust fan speed according to the pollution level. If the air purifier detects a low to negligible pollution level, it will lower the fan speed to the low or quiet setting. Only when a higher pollution level is detected will it increase the fan speed to Medium or High, depending on the reading picked up by the sensor. This way, the air cleaner will minimize energy usage, along with noise level, while ensuring the air in the room is adequately purified.

Recommended Surround Air model for Sensor Technology: Intelli-Pro XJ-3800

  • Odor, dust and allergen sensors to let you know not only the pollution level, but also the pollution type.
  • Clean air monitor lets you know the pollution level in the room.
  • Auto mode to maximize energy savings with performance.
  • Diagnostic sensors let you know when to replace filters, and when to clean the metal, electrostatic dust collector grid.
  • $189 with free shipping.

Other Surround Air Purifiers with Sensor Technology: Multi-Tech 8500Intelli-Pro 3


Sound Level

Some of the most effective air purifiers on the market also sound like a jet engine revving up for take-off. This would be fine if you didn't have to actually live in the same space you are trying to purify. But since you do, it is imperative to find an air purifier you can co-exist with. Air purifiers with fans that run higher than 200 cfm tend to be oppressively loud. Sure, you can run them on the lower settings, but why pay for that extra power capacity that you will rarely use?

Recommended Surround Air model for Quiet Operation: Intelli-Pro 3

  • Brushless DC motor which provides impressive power while running surprisingly quiet and smooth.
  • 180 cfm.
  • $159 with free shipping.

Other quiet but powerful Surround Air models: Multi-Tech 8500 ($129), Multi-Tech 8400 ($99)


Also See: "Surround Air Comparison Chart"