My gut reaction is that they don't work particularly well. If you have a forced air heating or cooling system, you might want to consider some kind of high efficiency filtration.

Thanks for your response.

Most electronic air cleaners were originally developed to remove combustion soot and other carbon based particles degrading the performance of high voltage components associated with military systems. Getting them to work effectively was very messy and labor intensive.
If you are interested in keeping a small room clean and are a bit handy, there is a way but it isn't cheap. You will need a Seville brand or similar tower style fan, a pair of aviation style snips, and a supply of expensive 3M Filtrete electostatic filter panels. You remove the metal support grid from the intake (outside) side of the filter (cutting, pulling, bleeding, and cutting) and and then bend and strap the whole filter around the tower covering the tower fan air intake holes. You would be surprised how quickly that portion of the filter darkens in a city environment. Then after several months it is time to cut off the dirty section and reinstall. Three to six filter panels a year, cost for them maybe $40 to $100?
Check into HEPA filter machines as well but adequate airflow and velocity can be a problem.

I have an air purifier and it works pretty well. Along with the basic odor eliminating air fresheners