In the design of noise‐critical spaces such as music and theatre performance and rehearsal spaces, low background noise levels are essential. Therefore, noise emanating from the supply and return air terminals of the HVAC system must be kept to a minimum. This requirement often dictates the need for many large terminals. This approach can be a very expensive alternative. In addition to the expense, the large area of duct terminals can have a negative impact on the room acoustics, particularly in a concert hall where sound absorptive materials/openings must be kept to a minimum. A number of different supply and return air terminals that create a minimum amount of noise at relatively high outlet velocities (up to 600 fpm) have been designed and tested. The results of these tests and guidelines for the design of low noise terminals will be discussed.