Assignment 4 – Specific Hood
A laboratory fume hood, hood opening area A = 40 ft2 (3.72 m2), face velocity = 100 fpm (0.5 m/s), entry loss factor f = 0.5. Assume STP.
- Determine the volume flow rate required.
- Size the duct to give a duct velocity of nearest 2,000 fpm (10 m/s) and round off the diameter to a whole number in inches or cm.
- Determine the hood static pressure (SPh).
- A canopy hood is being used on an open-surface tank, which is not located near any walls. The hood is located 1.2 m (4 feet) above the top of the tank. If the tank is 1.8 m (6 feet) long and 0.9 m (3 feet) wide and the contents are at room temperature, what airflow through the hood is required? Assume a control velocity of 0.75 m/s (150 ft/min).
- If a lateral slot hood is used to capture the vapor evaporated from the same open-surface tank with the same control velocity of 0.75 m3/s/m2 (150 ft3/min/ft2) of tank area. What airflow through the hood is required?