Jun 16, 2008 #1 jlf01 Mechanical Mar 25, 2008 2 Can any one tell me the formula, rule of thumb, for sizing the duct size for the relief air dampers on a vav system with no return fan. .05" sp. jlf01
Can any one tell me the formula, rule of thumb, for sizing the duct size for the relief air dampers on a vav system with no return fan. .05" sp. jlf01
Jun 16, 2008 1 #2 imok2 Mechanical Oct 21, 2003 1,311 For unducted return air shaft sizing, maximum velocities should be in the 800 fpm to 1200 fpm range through the free area at the top of the shaft (highest airflow rate). Gradually reduce the velocity down to about 500 fpm at the zone level see:http://www.energydesignresources.com/docs/db-04-avavsys.pdf Upvote 0 Downvote
For unducted return air shaft sizing, maximum velocities should be in the 800 fpm to 1200 fpm range through the free area at the top of the shaft (highest airflow rate). Gradually reduce the velocity down to about 500 fpm at the zone level see:http://www.energydesignresources.com/docs/db-04-avavsys.pdf
Jun 23, 2008 Thread starter #3 jlf01 Mechanical Mar 25, 2008 2 Thanks imock2 this is helpfull. Upvote 0 Downvote
