Just remember that when compressed air is applied in the direction of any fans, they tend to hit a rather high rotation speed VERY quickly which isn't good for the fan. I use a wooden pencil to stop the fan(s) from spinning and damaging themselves.
The Acer machine, assuming I have the correct model in my mind, has about 5 or 6 screws that allows you to remove the bottom cover that then exposes the HDD, RAM and fan. Mostly it is a failing fan rather than it getting filled with fluffy substances and dirt.
If you do venture into the belly of the beast, remove the battery first and don't have the power connected. Also be careful about static discharges from yourself to any of the components. Try and earth yourself to a metal part of the laptop before opening and then avoid rubbing your feet back and forwards on the carpet.
