Supply Air Grille Velocity

The point that air velocity becomes ineffective is called the terminal velocity.

Supply air grille velocity.

The maximum throw is the distance of air travel to a terminal velocity of 0 41m1s. Aluminum spiral supply grille with universal end cap single deflection 3 4 blade spacing blades parallel to long dimension us dl sv us dl is a supply return drum louver with adjustable deflection blades and volume damper. Low velocity design is very important for the energy efficiency of the air distribution system. Our wide selection of grilles registers diffusers and accessories includes a variety of shapes and sizes to meet any application and budget requirement.

Generally terminal velocity ranges from 150 down to 50 fpm. Outdoor air supply must be increased by 25. Doubling the duct diameter reduces the friction loss by factor 32. For each listed air volume the static pressure drop and two values of throw are given for each grille area factor.

The stamped face allows for 2 way air deflection coupled with the smooth glide technology to ensure a. Use this register for wall or ceiling openings. Flow velocity in air ducts should be kept within certain limits to avoid noise and unacceptable friction loss and energy consumption. The 102m series 2 way air register features a the 102m series 2 way air register features a high quality steel outside with a white powder coat finish and the smooth glide multi shutter damper to control the amount and direction of airflow.

Eventually the supply air will slow enough to become ineffective in mixing with room air. High air velocity at supply registers and return grilles resulting in air noise low velocity in certain ducts resulting in unnecessary gains and losses low velocity at supply registers resulting in poor throw and therefore room temperature control high air velocity inside fan coils and over cased. This is commonly considered to be the air within an envelope of 50 fpm 0 25 m s or greater velocity. The distance from the face to where this terminal velocity occurs is the throw.

Marshall noise control in music teaching facilities noise control engineering journal september october 1980 p 75. The minimum throw is the distance the air will travel to a terminal velocity of 0 64m1s. Leed 2009 ventilation points are gained by increased ventilation 30 beyond 62 1 minimums. Air velocities for the initial 10 ft of duct extending from supply register or return grilles should not exceed the values given in the table by more than 20 percent.

Low and medium pressure.