Laptop Fan On And Off

The fan in my laptop keeps going on and off while using it, now i know this is what it is suppose to do but the fan gets quite annoying, it is on and off like all the time, i thought normal activity it should come on, then go off then maybe back on again but not straight away, i have checked the temps of the laptop while the fan is coming on and its not even running hot, my other laptop is running hotter and the fan isn't even on with that laptop, it might come on every now and again but not on and off so it gets annoying, the laptop is a acer aspire 5717z?.

Use a vacuum to suck dust out of all the vents. Use compressed air to further remove dust from places. This will make the fan speeds more consistent.

I can't help you with overriding the fan speeds on your particular laptop i'm afraid.