However, the pressure is not sufficient to completely remove the fan wheel from the dust, I would have liked more pressure.
Shake the can help a bit, but overall it is too little pressure. I do not even needed fix the fan wheels, because the pressure was not enough to put them in motion.
Likewise, it is annoying to have ice-cold liquid is sprayed out when the can is not used completely upright. This endangers the sensitive electronics.
Nevertheless, I have thus lowered the temperature of the iMacs to about 6 degrees.