I am installing a 5 ton package unit. The supply air duct size is 12X19. Evap fan 2000 CFM. I plan on using a 24' horizontal duct with 10" round takeoffs. I would like to use 7 of these. The recommended velocity is 1000 FPM in trunck duct and velocity in branches not to exceed 800 FPM. My question is, am I in the ballpark here? Thanks for any input!