On Mon, 26 Sep 2011 21:04:08 -0700 (PDT), Andy
wrote:

I am looking for some recommendations.

I would like filter out cigarette smoke for a single room. Size is
about 15 ft. X 20 ft.

My research has shown that I need a unit that has both an ionizer and
a HEPA filter.

I disagree. I've bought a few of the Alpine Air XL-15's on ebay for
$50 or so. [$150 new on ebay-- $600 from the manufacturer]

My son uses them on used cars to get rid of smoke, pet, and
god-only-knows smells. Crank it up, leave it overnight in the car &
it is springtime fresh in the AM.

We've used them in musky rooms & smokey rooms with good results.

The ozone plates are sometimes fragile. [I'll go a year without
replacing one-- then have to replace 3 in a month] So if you get
one-- order a couple extra plates on ebay, too.

Jim