I leave my fan ON all the time. Some people think the fan is noisy and turn it OFF, but I cannot hear mine even when the room is quiet unless I listen very intently. You can get quieter replacement fans if you must. I think it may be on a thermostat, too.
I use the Samsung "eco-green" HDD's for my AZBoxes. I have many of them and they operate very cool, so that helps out a lot. If the HDD runs cooler, so will the rest of the box.
Another idea, to help ventilate and cool the AZBox Premium Plus is to leave the cover over the HDD bay OFF. You could even replace it with a piece of black, nylon window screen to keep it open. I have seen pix of several different mods to help keep the box cool. Such as adding more ventilation holes and slots to installing an extra fan. I have never been required to do this with any of my four AZBox Premiums.
RADAR