Experienced the exact same thing with my 1.4 Dynamique +. Theres no way of adjusting the sensitivity of the alarms on post 2002 Clios, according to Renault.
I spent 9 months going to and from my dealership trying to sort the problem. In the end, I wrote to Renault Customer Services who told my dealer to fit a brand new system. No problems since.
If youve got a faulty alarm, the test is to turn off the volumetric sensors (i.e. turn ignition on twice, then lock within ten seconds) and then open the window and wave your hands around. If the alarm is faulty, it will sound regardless of the fact that you have turned off the sensors. Show Renault, and youll prob. get a new alarm.
By the way, Im assuming theres no other possible cause, i.e. air through the vents.
