In laboratory-type facilities, a fundamental goal of energy engineers is to reduce the amount of exhaust air to the lowest safe level for any particular design because conditioned exhaust air is very energy intensive. Code and certification requirements that determine the amount of exhaust need to be verified with the authority that has jurisdiction over the facility design and operation; however, there are surprisingly few codes that stipulate the actual amount of exhaust for laboratory-type facilities. Certification standards must be carefully understood to insure that they are appropriate for the actual activities for which laboratory equipment and space are being used. Devices that exhaust air from a laboratory have evolved in response to concerns about safety and energy consumption. For fume hoods, the most important energy-efficiency measure is to incorporate variable volume exhaust airflow that changes with the position of the protective sash. Manifolding fume hoods, when appropriate, reduces exhaust system energy consumption. Manifolding can also reduce first costs and increase system flexibility. Optimizing stack heights and air stream exit velocities can minimize required energy to disperse exhaust stack effluent. Finally, even the most sophisticated, energy-efficient exhaust system can be rendered ineffective if operators are not trained and motivated to use the system to its maximum potential.