Do I need a fume hood? If so, what type?
Yes, we strongly recommend a fume hood be placed in all chemistry, A.P. Biology and integrated science labs. Typically, one 4'-6' fume hood per lab is plenty if you have "great" ventilation in the laboratory. (See Frequently Asked Question #1.)
For rooms where you may someday wish to install a fume hood, I would plan ahead and have the necessary design elements built into the building so the fume hood could be installed at a later date. Design elements would consist of allowing space to install ductwork and designing the roof to accommodate the motor/blower set and vent stack. All low-cost items during construction, but very expensive to do after the fact
Not all fume hoods are the same. For instance, if you are purchasing a 4' fume hood, make sure the hood can overcome a maximum external static pressure of 0.259 H2O at 100 fpm face velocity (720 cfm). All the other bells and whistles that come with a fume hood are to be selected based on your curriculum needs and local building codes.