It's for ds1's room (he's 14).
I open the windows to try and air the room, change his bedding regularly and he showers each evening, but his room still smells very stale.
I've tried scented candles, but hate air fresheners, so don't want to go down that route.
When I was younger I used to have an ioniser that I used in a room where I couldn't open the window and that worked very well.
I ordered an air purifier/ioniser from Amazon, but it's crap and I'm going to have to send it back 
Can anybody recommend anything?