Seems like it's never ending, but this one might, hopefully, not be serious.

When I start the car up there's fan type noise from the front of the car, like a fan spinning up but it stops after about 5 seconds, only to 'spin up' again a few seconds later. It only used to do this on startup until the car had warmed up, but it does it all the damned time. Even sitting in traffic I can hear 'whirrrrrr' then it stops, only to go 'whirrrrr' again.

If it makes any difference my aircon doesn't work, the usual pipes but it matters not whether the aircon button is on or off on the dash. It doesn't overheat and had a new Rad, thermostat and coolant about 3 months ago.

Any ideas if it's a bad thing or can I safely ignore it?

It's coming from the Engine bay!