Use a carbon | Odors are gases, not particles. They cannot be |
filter to remove | removed by the air cleaner or by any other filter |
odors | designed to remove particles. However, some |
| gases can be trapped by an activated carbon |
| filter or diluted with outdoor air. If odors are a |
| concern, talk to your heating and air condition- |
| ing dealer about installing a carbon filter |
| downstream of the air cleaner or providing an |
| outdoor air inlet. |
The electronic | Air ionizers have been marketed with claims |
air cleaner | about purifying the air and promising medical |
versus the air | benefits. It should be noted that supporting tests, |
ionizer | if available, are controversial and incomplete. |
| Air ionizers may generate a bit of ozone, and of |
| course some ions (air molecules with an electric |
| charge). This is what your electronic air |
| cleaner’s ionizer does, but with greater inten- |
| sity. However, air ionizers do not have good |
| collectors, if any. With air ionizers, the charged |
| dirt particles are collected by walls, floor and |
| furniture, requiring frequent cleaning of the |
| entire building to remove the effects of collected |
| contamination. By comparison, an electronic air |
| cleaner deposits contamination on the cell(s) |
| and prefilter(s) for easy cleaning. |
Ozone and the | Electronic air cleaners generate a very small |
electronic | amount of ozone, about 0.005 to 0.010 parts |
air cleaner | per million (ppm). The amount is highest when |
| the air cleaner is new. |
| The average person can detect the odor of |
| ozone in concentrations as low as 0.003 to |
| 0.010 ppm. The U.S. Food and Drug Adminis- |
| tration, and Health and Welfare Canada |
| recommend that indoor ozone concentration |
| should not exceed 0.050 ppm. As a compari- |
| son, the outdoor ozone level in major cities is |
| sometimes higher than 0.100 ppm. |
16 |
