Ventilation

a change of air, resulting in a supply of fresh air. The need of ventilating rooms and approved methods are discussed under the article on HEATING AND VENTILATION. We may add here that an average adult person at rest gives off, manufactures, about .6 of a cubic foot of carbonic acid gas per hour. Outside air contains about four parts in 10,000 of this gas. The gas produced by an adult per hour, added to that already in the air, will bring the amount in 3,000 cubic feet of air up to the amount of six parts per 10,000, the limit beyond which we ought not to go. It follows, therefore, that an adult ought to be supplied with 3,000 cubic feet of air per hour or 50 per minute. Children do not vitiate air so rapidly. The amount of air that should be supplied to each person per hour may be stated in cubic feet: