- You identify a fan with inlet and outlet conditions:SPin = -3.65” w.g.,SPout= +0.60” w.g., and VPin= VPout = +0.45” w.g.What are FTP and FSP for the fan?
- You are designing a ventilation system with the following parameters. What is the required shaft horsepower (sph) for the ventilation system, and what rated power motor (rhp) would you choose?
FTP = 15.0 inch w.g. Q = 1,300 scfm ME = fan efficiency = 0.65
Kdl = 1.05 STP (d = 1) c = 6356
- What is the new flow rate, hood static pressure, and brake horsepower expected when rpm is increased to n = 1,450 rpm? Hint: Use fan law equations.
|Initial Conditions||Conditions after Increase|
|n = 1220 rpm||n = 1450 rpm|
|Q = 1,300 scfm||Q = ?|
|SPh = 0.85 inch w.g.||SPh= ?|
|bhp = 1.3 hp||bhp = ?|
- The flow rate of an existing ventilation system is to be increased by 25%. About how much more power will be required?
- The hood static pressure is first measured at SPh = -0.75” w.g. and volume flow rate through the hood is Q1 = 1040 cfm.If the hood static pressure changes to SPh = -0.55” w.g., what is the new flow rate, Q2? Assume other conditions remain same. Hint: use equations from chapter 6 or 8.
- Based on measurements of amps and volts, it is known that a ventilation system fan consumes approximately 8.0 shp. Other known values of the system are shown below. What fan total pressure (FTP) is likely to be measured?
STP (d = 1), Q = 10,000 scfm, ME = fan efficiency = 0.60 (60%),Kdl = 1.7.