I think the ionic filters (like the ionic breeze from sharper image, they have buy one get 2nd 1/2 off) would be a great solution because of the low cost of ownership. But I am not too happy with the failure rate.
The Ionic Breeze is the most overpriced and worthless piece of crap on the market, but I would love to be making the profits from all the suckers falling for the slick marketing campaign.
Consumer Reports tested the Ionic Breeze and it came in dead last, far and away the worst performing air purifier they've ever tested in the 10 years they have been testing air purifiers. Both FDA and EPA do not advise appliances which rely on ozone as a method of remediating odors or killing microbes. Ozone production is a drawback of electrostatic ionizing filters, it is not a "feature" in any way.
I should clarify that the efficiency of the Ionic Breeze isn't all that bad, but filtration efficiency is only half of the equation. The other half is filtration VOLUME, how much air can be remediated at a particular efficiency in a given length of time. This is where the Ionic Breeze fails miserably.
One of the touted 'features' of the Ionic Breeze is its very low operating noise, which it accomplishes by moving very little air through the unit. The less air moved, the longer it will take to achieve the same level of 'cleaning' of any given room size. You cannot move reasonable volumes of air without generating a little noise in the process. That's not to say the loudest product is always the best or moves the most air, if that product is poorly designed it can be unnecessarily loud.
Another drawback of electrostatic purifiers is that the filtration efficiency begins to rapidly decline as the plates become dirty. Electrostatic purifiers can be every bit as efficient as HEPA, but only if you're inclined to keep the plates clean at all times, which means you'll be washing the unit weekly. This underscores one of the flaws inherent in the Consumer Reports test methodology, which is that CR's tests do not take maintenance into account as being a positive or negative factor which might give weight to someone's buying decision.
The best performing unit in the Consumer Reports tests several years running is the Friedrich C-90 which is an electrostatic unit. CR only tested to a certain 'level' of room clearance using spectrometers to measure the particulate concentration in the air. It only took the Friedrich model an hour or so (IIRC) to achieve this level of clearance, which became the benchmark for all others. This only simulates how the Friedrich would perform PRESUMING the user will exercise a high level of vigilance in maintaining their unit to keep the electrostatic plates clean.
The efficiency of HEPA filters, however, actually increases as they become dirty, until they are so 'plugged' with contaminants that air can no longer pass through at a reasonable rate. HEPA filters are very low maintenance, which can be a key buying factor. I don't want to be cleaning my air purifier every week, and I don't know many others who relish the thought, either.
