THIS YEAR'S ADDED TESTS AND RESULTS

Long-term air cleaning. We tested the Sharper Image Ionic Breeze and the Honeywell Environizer against two high-scoring air cleaners, the Friedrich electrostatic precipitator and the Whirlpool HEPA filter.

We gauged how well each air cleaner could handle the periodic introduction of small amounts of pollutant into a sealed test chamber over a 6-hour period. One set of tests used smoke, another fine dust. A second set of tests gauged how well each cleaner worked for the next 17 hours, after the last injection of pollutant. For both sets of tests, we ran the Ionic Breeze and the Environizer on high to maximize performance; the others were on low, their quietest setting.

The better an air cleaner does in lab tests like these, the better it will perform in a household setting. But as Prof. Lippmann explained, if there is “very little dust removal over 100 minutes,” then running an air cleaner for 24 hours “is not going to make it an effective air cleaner when infiltration of air containing particles into a room continues.”

The results. The Ionic Breeze and the Environizer didn’t come close to the performance of the others. As the graph below shows, the Friedrich and Whirlpool have very high rates of air-cleaning. The Ionic Breeze and Environizer had very slow rates of cleaning, which did not improve over time; those two products never achieved the same low pollutant level that the Friedrich and Whirlpool attained.

Noise study. We asked 40 people in 20 households to run the Friedrich and Whirlpool in their bedrooms continuously on low speed for a week.

The results. Thirty-five of those using the Friedrich said they didn’t notice the noise, hardly noticed it, or noticed but didn’t find it bothersome. With the Whirlpool, 29 people didn’t notice the noise at all, hardly noticed it, or noticed but didn’t find it bothersome. Two said the Whirlpool’s noise was so annoying that they wanted to turn the machine off. No one said that about the Friedrich.

Given those findings, you could expect most of the air cleaners we tested to be quiet enough on low speed for most households. Based on our lab measurements and judgments, both fell within the range we call very good for noise on low speed.


THE BOTTOM LINE

The Ionic Breeze and the Environizer are quiet but ineffective. A comparable product, the Hoover SilentAir 4000, performed poorly in our standard test; we chose not to put it through any extended trials. Considering how slowly these three products worked, our advice is to avoid all three. There are much better choices.