Took it down for an air-con cleanse because it smelled (it had been little used by the PO for quite a while) and then got it in the air to try and work out what to do with the poorly fitting exhaust. It's secure enough, but leaking at 3 joints. Also did a noise measurement and was pleasantly surprised with a static measurement of <90 dB at 5500 rpm. Maybe it's not as loud as I think it is.