Reduction of classroom noise in order to improve children's learning environment has to be approached from several directions, of which control of internal noise and control and of break–in from external sources are the principal ones. Air conditioning noise is a major problem in many North American classrooms, representing the main internal noise source. Responding to this, a recent ASHRAE Winter Meeting included a highly successful and up–to–the–minute Seminar on Classroom Noise, stressing the need for quieter HVAC systems in order to achieve improved classroom levels.