local exhaust ventilation 6

1-Please list 4 different methods that can be used for industrial ventilation system balancing:

2-What are the advantages and limitation for using blast gate or damper to regulate air flow in ventilation system?

3-Please define the governing SP in balanced design:

4-If two branches are designed to enter a main exhaust duct, the branch A with a slot hood will require a total SP of – 5 “wg and 6.5 scfm, while the branch B with bellmouth entry hood requires to have a total SP of – 4.5 “wg and 5 scfm. Please determine: 1) which branch will serve as the governing duct and why? 2) Determine if you are able to calculate Qcorr; 3) Calculate Qcorr for the non-governing duct.

5-A ventilation system with two branches: the branch A requires to have VP of 5 “w.g. and Q of 4.8 scfm, and the branch B needs to have VP of 4.2 “w.g. and Q of 4.5 scfm. Please determine the resultant velocity pressure and flow rate at the junction (combined branches). Assume STP.

6-The circumference of a round duct is about 37.5 inches. The average velocity pressure (VP) of air flowing in the duct is 0.30 inch w.g. at standard conditions (STP). Please calculate: 1) Duct diameter; 2) Average duct velocity, 3) Air flowrate Q.