I'm confused: what is an ionizer and what is a HEPA filter?

The Ionic Breeze is an ionizer type of air purifier. It works by electrically charging air born particles and trapping them on oppositely charged plates. HEPA stands for high efficiency particulate air filter. Air purifiers use either ionization or HEPA filters.

How do I decide what air purifier to buy?

When it comes to shopping, people are always advised to check out products with Consumer Reports. In the Feb. 2002 issue and the Oct. 2003 issue, the magazine stated that the Ionic Breeze was "ineffective" and produced "almost no measurable reduction in airborne particles." Sharper Image, the maker of the Ionic Breeze, sued for liable. Their suit was dismissed.

In May of 2005 Consumer Reports struck again, claiming that the Ionic Breeze created unsafe levels of ozone. Sharper Image's CEO fired back saying, "This Consumer Reports piece is, in my view, irresponsible in the way it casually and unscientifically speculates about public health and safety." He pointed out that common household electronic devices like hair cryers and TVs also produce ozone. He also pointed out that the Ionic Breeze meets the limits set by the FDA--50 parts per million.

In a long report, the American Lung Association quotes Consumer Reports several times and points out the dangers of ozone for people with asthma and other chronic lung disease, elderly people, and infants. However the report did not condemn or recommend any specific air purifier.

Ok, enough with the doom and gloom. You still haven't told me what to buy.

You are a very stubborn customer. Consumer Reports says that one ionizer works. This is the Freidrich which the magazine claims gives a "fine" performance with "negligible ozone." Its cost is $450. The Whirlpool 45030 which uses a HEPA filter got high marks also. It costs $250. All ionizers are much quieter than air purifiers using HEPA filters so it comes down to how important peace and quiet are to you.