Cleaning the Macbook Vent

Hello,

I've had my macbook for about a year now. Its work pretty well. However I notice the fan turns on more often. I think its partially due to the vents being partially clogged with dust particles.

I have another laptop that I clean every month, via opening and air dusting the vents in all directions and reseating the replaceable parts.

My Question;

Is there any way I can clean out the vents in the macbook - without having to open it up? I still have 2 years left on the warranty and I'd like to preserve it. Could I perhaps use vacuum (the hose attachments on most vacuums)?

Also I'd like to double check, it is ill advised to actually use the air duster pointed inwards the vent in the back right? (I've never done it as something seems logically wrong about blowing dust inward <.<)