to do this is in the open air; if the practice is indoors, the windows should be wide open. VENTILATION Ventilation is simply the bringing of air into a house and then taking it out again, but there are right and wrong ways of doing this simple thing. It is hygiene that teaches us why we must breathe pure air and how much we need, and it is sanitation which teaches us how to ventilate our buildings, so that pure air in sufficient amount may be secured. The air in schoolrooms should be changed at least four times every hour, and every pupil should have not less than 180 cubic feet of space. If the length, breadth, and height in feet of the schoolroom are multiplied together, and the product is divided by the number of pupils in the room, the quotient should be 180 or more; otherwise each pupil has not sufficient space or air for good health. Crowded schoolrooms always cause more or less illness. It is impossible, in cold weather, to ventilate a schoolroom properly by windows and doors. If we try to introduce air through windows and doors in the winter time, the room becomes cold and draughty. This interferes with study and recitation, just as the bad air does, and both conditions cause sickness. Every schoolroom should have a pipe, or duct, in the wall to bring in fresh air, and a second duct to take out the impure air. If these ventilating pipes are not practical, and the room is heated by a stove, it is still possible, with care and judgment, to secure a fair amount of fresh air. During recess the windows should be opened and every child should remain out of doors. If it is raining at recess time, then, with the windows open, the breathing exercises already described should be practiced. When windows must be used for ventilation, it is a good plan to place a board five or six inches wide, and as long as the window is wide, under the lower sash, so that the cold air comes in through the space between the two sashes, is forced upward into the room, and does not reach the pupils until it becomes warmed. If the room is heated by means of a stove it should have a sheet iron jacket around it: This will direct the heat upward and cause it to diffuse more evenly through the room. A jacket around the stove will also protect near-by pupils, keeping them from being overheated. HEATING OF SCHOOLROOMS Heating and ventilation belong together. The fact that hot air is lighter than cold air is taken advantage of in heating schoolrooms. A furnace, which is a large stove surrounded by either a brick or an iron jacket, is placed in the basement, and from the space between the stove and the jacket, pipes lead to the schoolroom. There is also a large pipe connecting this space with the outside air. The cold fresh air enters by this pipe, called the cold air pipe, passes over the hot surface of the stove, and so heated passes upward through the hot air pipes into the room. By this method the air which warms the room, though hot, is fresh, pure air. The objections to stoves in a room are, that they heat much of the same air over and over, and that the school is disturbed when fuel it put on the fire. Experience, however, proves that schoolhouses which have more than eight rooms cannot be successfully heated and ventilated by furnaces. A better system for a large schoolhouse is the fan or forced system. This requires an engine or motor of some kind in the basement to propel a circular steel fan, which forces pure air from outside over hot steam coils and then through pipes into the schoolrooms. If a schoolroom is heated by radiators in the room, there should be back of each radiator an opening in the wall to the outer air. This opening will bring in fresh air, which, as it passes over the radiator, will be warmed. Ventilating engineers and architects call this “direct- indirect heating.” They call it “direct heating” if a room is heated by stoves or by radiators which have no opening in the wall to the outer air. This subject will be discussed more fully in the chapter on ventilation. MOISTURE Finally, it is important that there should be a certain amount of moisture in the air we breathe. If the air is dry and hot, it takes moisture from the nose passages, from the throat, and from the lungs. This is uncomfortable and may cause disease. The air of schoolrooms may be kept moist by water pans in the furnaces in the basement, and all modern furnaces are so supplied. It is an easy matter to keep pans filled with water on the tops of stoves, and thus keep the air moist. This matter is frequently neglected because its advantage is not understood, but neither it nor any other help to good air should be forgotten. The first thing that all of us do is to breathe, and only as long as we breathe are we alive, so it is truly necessary to consider how important to our welfare good air and correct breathing really are. <Callout type="important" title="Ventilation Importance">Proper ventilation in schoolrooms ensures students have enough fresh air for optimal health and learning.</Callout> <Callout type="gear" title="Window Ventilation Aid">Using a board under the lower sash of windows can help warm incoming cold air before it reaches pupils, improving comfort during winter ventilation.</Callout>
Key Takeaways
- Proper ventilation is crucial for maintaining good air quality in schoolrooms.
- Each pupil should have at least 180 cubic feet of space to ensure adequate air circulation.
- Direct-indirect heating systems are more effective than direct heating methods for large buildings.
Practical Tips
- Ensure windows are wide open during indoor breathing exercises or activities.
- Use water pans on stoves and furnaces to maintain proper humidity levels in the room.
- Install ventilation ducts to bring in fresh air without causing drafts or cold spots.
Warnings & Risks
- Ventilating schoolrooms improperly can lead to illness due to poor air quality.
- Overheating from direct heating methods can cause discomfort and disrupt learning.
Modern Application
While the chapter focuses on historical ventilation techniques for schoolrooms, its principles of ensuring adequate space per person, maintaining proper humidity levels, and using efficient heating systems remain relevant today. Modern HVAC systems have improved these concepts but understanding the basics from this text is still valuable.
Frequently Asked Questions
Q: Why should windows be wide open during indoor breathing exercises?
Opening windows allows for better air circulation and ensures that students breathe in fresh, clean air rather than stale indoor air.
Q: What is the purpose of placing a board under the lower sash of windows?
Placing a board under the lower sash helps to direct cold incoming air upwards into the room, warming it before it reaches students and preventing drafts.
Q: How does indirect heating differ from direct heating in schoolrooms?
Indirect heating involves bringing fresh air through pipes or ducts that pass over a heat source, ensuring the air is both warm and fresh. Direct heating methods can lead to overheating and poor air quality.