You might be scratching your head wondering what that appliance up above is. At quick glance, it looks like a mainframe computer, circa 1988. But inside the IQAir HealthPro Plus system's industrial case comes the most serious air purification we've ever tested. This past weekend we ran a battery of tests using a laser particle reading device in a real world environment (our apartment), checking if all the hype about this machine was a bit of balderdash or really the mean clean machine promised by IQAir, pitting it against two other consumer grade HEPA air purifiers. Check out how each air purifier performed after the jump...

The IQAir HealthPro Plus comes with a long list of accolades, including top recommendations from Consumer Digest, Discovery Health, Allergy Buyers Club, Consumer Search and Swiss based IQAir is an official partner of the American Lung Association. But although test lab results are a good reference when purchasing an air purification unit, the real proof is using these units in less than ideal conditions, which perfectly describes our 1917 studio 637 sq. ft. apartment in urban Los Angeles. Anyone living in our neighborhood will attest that air quality inside and outside the area is less than ideal, with dirt, dust, allergens and myriad of other pollutants a common irritant.

Using the IQAir Particle Scan Lite (which operates by suctioning in a sample of air and evaluating particles per cubic foot), we began with a reading just outside our door for reference. A shocking 2.5 million particles per cubic foot was our average reading outside our door in Silver Lake (a very slight breeze, 71 degree weather, moderate humidity); inside, our base reading was one third less, at 800,000 cfm. In comparison, a hospital surgical room is kept at a minimum of less than 100,000 cfm. We also took measurements in different areas of the open apartment beforehand to see how well the IQAir HealthPro Plus would do circulating air in a non-enclosed environment, alongside testing the unit within a closed door environment.

Out of the (big) box, the unit comes fully assembled, and is ready to operate besides adding on four optional snap-on caster wheels. We had the unit up and running in just a matter of minutes. Once plugged in, we pumped up the unit to it's highest setting, and like almost all HEPA air purifiers, at full speed the IQAir HealthPro Plus is loud. Realistically, most users will likely use the unit at a setting of 3-4 (6 being the highest), which provides sufficient air flow while also only creating minimal sound. It's also worth noting that the sound produced tends to blend away with some time, because the circulation motor has been sandwiched inbetween all the filtering elements, and also engineered to create a full-spectrum sound that flattens in short time (think of the din of a ballpark opposed to a smaller crowd screaming, as an example). The truth of the matter is that a sufficient air flow is required for circulation for optimal filtering, so finding the highest setting within toleration is important. Sleeping with the unit set at its middle setting has proven to be completely acceptable, and the unit may be even quieter in a carpeted environment.

The IQAir HealthPro Plus uses three independent filter cartridges, each specifically created to remove a minimum of 99.5% particles of 0.003 microns in size...that's the size of the smallest virus or bacteria, explaining why these units are used in Hong Kong Hospitals for SARS patients.The first pre-filter removes most particles, then this air is then pushed through a very tightly manufactured cell filter that removes odors and gases, then it is finally pushed through the final stage via centrifugal fan through a true HEPA membrane constructed of several square meters of pleated filter, resulting in an advertised 99.5% elimination of particles. In comparison, our two other HEPA air filters are advertised to remove 99% air particles at .3 microns or larger, referring only to the efficiency of the actual filtering membrane. Since 90% of particles fall under .3 microns in size, we needed to test how each unit performed filtering our apartment's air.

First was the Holmes HEPA air purifier we purchased from Target, a one stage filtering unit. This unit has been primarily used in our main bedroom. Set at mid-speed, the Holmes model is fairly quiet. Putting the laser particle scanner next to the outgoing filtered air and taking readings at all points of the exhaust, the Holmes surprised us with an outgoing stream of air rated at 25,000 cfm, very close to 97% efficiency. Around certain parts of the unit, there seemed to be some minor air leakage that bumped up the readings to an average of 50,000 cfm, illustrating that the HEPA label is one that only applies to the filter itself, and does not necessarily apply to the whole air purification system. Overall construction of the unit must be tightly engineered, or like HEPA vacuums, particulate matter could mingle with filtered air.

Our Honeywell HFD-130 Germicidal HEPA Air Purifier (cylinder unit) was purchased because of the glowing reviews of it's quiet operation and also it's marketed germicidal properties, and has been in use for the last 2 years (and no longer available). The Honeywell model uses both HEPA and IFD (intense field dielectric) filtration, a model we liked because there was a washable and reusable filtering unit. Unfortunately, when tested, the Honeywell put out a whopping 250,000 cfm at all speeds, resulting in only removing 69% of particulates in our apartment. The low profile and weak fan likely contributed, alongside the washable filter, which doesn't perform as well as filters that need to be replaced.

Finally, we put the particle scan up to all parts of the IQAir HealthPro Plus and watched the figure drop down in a matter of seconds, until finally, the unit read "0". The triple stage filtering unit had removed all particles from the air (the laser unit could read up to .3 microns in size). This might have been the cleanest air I've ever breathed in all of Los Angeles and was impressive considering the unit was operating at setting "3".

We also left the IQAir HealthPro Plus operating for 5 hours in our apartment with the windows closed, enjoying an afternoon while the air filter worked it's magic. The figures for before and after, throughout the whole apartment with unit set in the middle of the living room (setting "3"):

• Living room: 800,000/400,000


• Bedroom: 900,000/700,000


• Office: 700,000/650,000

When left in a closed door office for one hour, the IQAir HealthPro Plus reduced a 650,000 reading down to 130,000 at its highest setting, and that was in a room with a window air conditioner that let's in some outside air.

*for reference, our carpet registered 1.5 million cfm when slightly agitated and our closet put over 2 million cfm!

As impressive as all those figures are, what really struck me personally is the notable effect it had on my allergy prone girlfriend. I am not exaggerating when I say Emily goes through several tissues a day, sniffling because of a sensitivity to allergens and pollution that spring up throughout the year. In the matter of a day, she went from regularly hitting the old box of Puffs, to hardly requiring any tissue. Emily's allergies had subsided significantly , if not almost completely disappeared (funny, she didn't notice the change until I pointed it out, since she's accustomed to the sniffling as a regular aspect of her life). Upon stepping outside or inside the unfiltered closet, her allergies returned. As someone who lives with an allergy sufferer, the change was dramatic and immediately noticeable and illustrated how much interior air quality affects immune system health.

In terms of costs for operation, using the IQAir HealthPro Plus costs about the same as operating a 150 watt incandescent bulb at medium setting. Filter replacement costs per year is about $97, with the pre-filter needing to be replaced every 6-9 months. Additional features included are a remote control, automatic filter monitoring and a digital scheduling timer. The HealthPro Plus is priced according to it's serious performance, costing anywhere between $795-$835 online. But we cannot recommend this thing enough...it is one of the few products that completely lived up to its claims with immediate noticeable effects in a real world environment. If you've got serious allergies, asthma or pollution, the price honestly doesn't seem far off the mark for an industrial grade home purifier. You'll likely make up the cost in reduced reliance on allergy medications and tissue paper.

Next up, HEPA vacuum cleaners...since we might as well get the most use out of this $2000 laser particle reader that we've got on loan.

• Pros: excellent performance; immediate results; quality construction throughout; medium setting sound is acceptable; full 5 year parts and labor warranty
• Cons: caster wheels could be improved; aesthetically speaking, not a beauty; initial cost is expensive; at highest setting, very loud

More information from IQAir about the IQAir HealthPro Plus here.