I would find the fans on the desk would be in the way or not close enough so I deiced to make a solder fume filter attachment for a camera boom arm. All parts are easy to find on ebay. 12cm fan as strong as possible. 130x130x10mm active carbon solder filter. m3 bolts and wing nuts.
Will fit on most printers in 3 parts and I included one part with the helping hands and one without it's your choice.
Take a look at the video.