If you want something done right, do it yourself! Nothing could be truer when rating air purifier performance. Trustworthy reviews are scarcer than Dodo birds. So here is a ten point checklist to help you do your own air purifier rating.
#1 Determine the Type of Air Purifier
This is simple enough. There are six types widely marketed as air cleaners. Here is the bottom line:
HEPA uses a specialized filter capable of removing particulates down to .01 micron. This includes mechanically or chemically produced dusts and mists, biologically produced allergens and pathogens like bacteria and viruses. The 0.3 micron size often stated in ads refers to the Most Penetrating Particle Size. It only allows a mere three in ten thousand of these particles through.
HEPA Type: Maybe as good as 95% HEPA performance, maybe as bad as 50%. Who knows? Real data is hard to find. If you don’t know what you’re getting, why buy? Steer clear of anything labeled something-HEPA or HEPA-something.
Electret Type Electrostatically Charged Fibers make the best furnace filters you can buy. When used in an air purifier, like the 3M Ultra Clean, they do a good job. Unfortunately effectiveness declines steadily and they should be replaced every three months. A low initial cost is offset by filter replacements over the life of the unit. Good for allergies but compare lifetime cost against the better HEPA units.
Electrostatic Precipitators: Initial efficiencies lie in the 50% to 80% range, similar to HEPA-type filters. Unfortunately plate loading can reduce efficiency by as much as 80% in as few as three days. Regular maintenance cleaning is a must. Ozone is produced, often at dangerous levels. Avoid them.
Ionizers use high voltage to electrically charge particles causing them to “static cling” to something. Unfortunately they cling to walls and furniture producing the dreaded “black wall effect.” The EPA thinks they may also cling to your lungs. Avoid them.
Ozone Generators are banned in Canada, all but banned in California, and are very much discouraged by agencies like the EPA. Ozone sickens and kills. Reject utterly.
#2 Size Matters When It Comes To The Filter
More filter surface means less resistance to air flow, thus more air flow. More particles are captured with each pass. Room air is cleaned faster. The filter lasts longer before replacement.
#3 Total System Efficiency
Just because it has a HEPA filter doesn’t mean its nearly 100% efficient. Some air purifiers bypass air to help reduce backpressure and cool the motor. Some leak like sieves due to poor construction. Any air not going through the filter is air not being cleaned. Look for an air purifier proud to verify total system efficiency like the IQAir HealthPro series.
#4 Air Changes per Hour
For greatest health benefits you need 4 to 6 air changes per hour. This should be measured on some speed other than high. High is always the noisiest speed. So unless you’re fine with the sound of a hurricane in your home, find one that exchanges the air sufficiently at a lower speed.
#5 Filter Costs
Air purifiers with separate pre-filters, main filter and gas phase carbon filter usually cost less in the long run than those with fully integrated filter systems. Long filter life will also reduce your long term costs.
#6 Filter Changing Ease
Most air purifier manufacturers make it easy, but there are some that require tools and a major disassembly operation. Top quality doesn’t have to be complicated as proven by IQAir air purifiers.
#7 Filter Change Indicator
Why change the filter if you don’t have to? Then again, running a clogged filter isn’t doing you any good and may stress out the motor. The best way to know when the filter needs changing is by a pressure sensitive switch that detects when increased backpressure against the filter indicates clogging. You can find this system in the IQAir HealthPro series.
#8 Gas and Odor Removal
Many manufacturers have a pathetic carbon impregnated fiber pad. These few token ounces of activated carbon can’t remove much. You need many pounds of activated carbon. Special treatments with catalysts and chemisorbers can enhance gas removal ability. Make sure it targets the pollutants of greatest concern to you because each carbon blend is focused on different chemical contaminants.
#9 The Warranty
Good air purifiers last. Most top models come with no less than a five year warranty on all parts including the motor. I’ve seen eight and ten year warranties from companies like AllerAir. Their record proves their air purifiers really do last this long and longer. I have an AllerAir 5000 that’s going strong after five years.
#10 Return Policy
Most top quality air purifier manufacturers have a 30 day return policy. Some, like IQAir allow up to 60 days. This isn’t for defects. You have a warranty for that. This is to allow you time to personally test the air purifier and see if it satisfies your needs. Don’t consider any air purifier you can’t test and return.
Would you like even more tips about how to compare air purifiers? I invite you to take advantage of free, instant access to home air purifier information at my site http://www.Home-Air-Purifier-Guide.com. J Alan Rodgers – The Air Purifier Expert