On Sun, 25 Jun 2017 09:17:06 +0100, "Brian Gaff"
wrote:

These fans have always seemed a bit of a black art.

There does seem to be a fair selection of configurations that's for
sure.

I have one and it seems
to be taking longer than it used to to get to any particular speed nowadays,
though does not get very warm.

We have one on the wall in the kitchen and I think airborne grease
gets into the bearings and makes them drag till the motor (and / or
bearings) warm up.

I guess eventually things just tend to wear
out but not looked inside while it still goes around.

I replaced the blade on mine (plastic went brittle and broke whilst
being cleaned so replaced it with an ally one) but am due to try
washing the bearings out and re-lubing them to see if that helps it
start up quicker.

Cheers, T i m