This depends on how much smell is in the room. HEPA filters won’t provide any sort of removal of scents that aren’t attached to larger particles such as dust, hair and pet dander. A carbon filter binds to smoke and will be your best bet for removing it. However, depending on how much smoke is in the room, and the room size itself, an air purifier may not be much help. If smoke is constantly being produced, it’s going to be hard to contain it. Your best bet is to remove any items that have smoke smell locked into them, use a carbon filter air purifier for large rooms, and only smoke outside.