text: can a nozzle be used as an air cooler?   if you mean the air blowing through the nozzle, then yes you can.  the air has to be under pressure and as it flows through the nozzle the pressure drops suddenly which causes a cooling effect.  this is known as the joules-thompson effect or j-t for short.  it is used in industrial processes to cool gas streams.  the drawback is that unless you have a large pressure drop ( probably at least 30 or 40 psi) the cooling will not be significant.  the power required to raise the air to that pressure is quite a bit and the noise the nozzle would generate make it unsuitable for much outside the industrial area.  it would not be as efficient or as quiet as your home air conditioner for example.