1-Why is high flow velocity (usually 2,000 – 6,000 fpm) in ductwork necessary?
2-When selecting and designing ductwork, why round duct shape is usually better than others (ex. Rectangle, square, oval)?
3-Look at Chart 10 and determine the duct wall roughness correction factors (R) are affected by two factors including ____________________ and _________________.
4-In a LEV system with the fan running, at a point after the fan and before the exhaust stack, the pressure in the duct will be________ 0 (<, = or >)
5-Review chapter 3 and 7, use your own words and discuss where and how air turbulence is formed in ductwork.
6-Use your own words and discuss the good(s) and bad(s) about air turbulence in ductwork.
7-List the factors that can contribute duct friction loss.
8-Modified Exercise 7-4: At STP, what is the duct friction loss for a square galvanized duct, 16.47 inches on a side (width or height) and 10 ft in length, with an average duct velocity of 6,000 fpm? Hint: Friction loss = K*VP*L*R*df, you need to use both Chart 5 and 10.
9-If the TP is -1 “wg in the duct in the above question (Modified Exercise 7-4), what is the SP in the duct? Hint: look at chapter 3 to find an equation to calculate TP from VP and SP.