I've got a Sharper Image tower fan/ionizer, too. My exhaust does a fine job at eliminating odors from the grow room, so I keep the Sharper Image in my living room. One time, my wife accidentally left a whole rack of fish fillets in the oven too long, and stunk up the entire house like burnt fish. This wasn't too long after we got the tower fan, so we decided to put it to its first real test. Within an hour, the entire living room and upstairs hallway were odor free. When we adjourned upstairs for the evening, we discovered that our bedroom still had a fishy funk to it...but the rest of the house didn't!

If you're going to use one inside a grow room, I wouldn't keep it facing any of the plants. It should tame the smell of just about any sized room, but it might end up making the buds themselves smell like nothing. And that would just be weird to smoke.