There is likely accumulated dust so the fan is working hard to pull in air but can't with the dust in the way... Remove the fan and peel out any dust between the fan and the intake vent. I did this today and removed a strip of dust about 1/2 cm x 4 cm in size!! Now the fan is functioning as it did 8 years ago!
Once they have, you'll be able to view a graph of their reputation gained over time.
Here's a preview of what the graph will look like:
No reputation gained yet.