A range hood removes air over a cooking surface and may have lights too. Usually it attaches to the underside of a cabinet. The bottom of the hood should be about 24 inches above the cooktop.
Range hoods are rated for the amount of air they can move in CFM (cubic feet per minute). Ducts more than a few feet long or that make several turns to reach the outside reduce the flow. Consider purchasing a ductless unit, which filters the air and sends it back into the kitchen.
To replace a range hood, shut off power and remove the existing hood. Take the hood with you when you buy a new one to make sure the ductwork lines up.
About 6 hours to cut holes, run cable, and install ductwork and a range hood (not including cutting a pathway for the cable and patching walls)
Voltage tester, drill, long bit, drywall saw, jigsaw, hammer, fish tape, long-nose pliers, screwdriver, strippers, tin snips, lineman's pliers
Stripping, splicing, and connecting wires to terminals; running cable through walls; cutting holes into walls
Find power source and make sure the range hood does not overload the circuit. Spread a drop cloth on the floor below.
Range hood, cable and clamps, ducts, duct tape, sheet metal screws, wall cap, caulk, wire nuts, electrician's tape