There are many reasons for air-conditioning schools and among them are--(1) the improvement of learning and teaching efficiency, (2) effective use of the educational plant for a greater part of the year, and (3) more efficient use of space through compact building design. Five climate control techniques are cited as providing optimum teaching-learning environments--(1) control of individual classroom temperature within prescribed limits, (2) dilute odors to an acceptable minimum, (3) cleanse the air of dust, pollen, etc., (4) provide an acceptable and uniform air pattern, and (5) hold relative humidity within practical comfort standards. Advantages and disadvantages of five basic school air-conditioning systems are given. (RH)