Business has found this out already. Do you know of any factory, good school, bank or department store, where there is not installed some sort of ventilation apparatus including weather strips as well? Of course not. Why? Because fresh air keeps costs down and keeps health up. On this relation of health and output, efficiency depends. Does it not flash into your mind now that if housewives thought more of home ventilation and especially kitchen ventilation, you might have improved service, better tempered cooks, and more satisfactory life in general? Of late there are cults of out-door fiends. All kinds of cold-attracting, pneumonia-coddling out-door fanatics, who try to tell you it is good to sleep in draughts, to have cold feet, and the like. Their advice is wrong. The thing to do is not to subject yourself to the rigours of cold, but to approximate, in your warm, comfortable rooms, the sweet clean purity of out of doors. And this is easy to do by proper ventilation. Ventilation can render air even better than the outdoor variety by purifying it of dust and by supplying it with the right amount of moisture and motion. For the ordinary home the great air conditioners and ozonators, which are installed in institutions and factories, are unnecessary, so we will not consider them. The best, simplest and least expensive ventilating system for the home is the system regulated by fans and blowers, and to this method we will introduce ourselves. Now, it is conceded by ventilating and heating engineers that the air, to be healthful, must be in ceaseless motion, and it must be renewed constantly and evenly. In other words, it doesn’t make much difference if the air is burdened with carbon dioxide gas which we exhale from our lungs, as it does if the air is stationary. Hence the use of air agitators such as fans, etc. The theory is that, as the pores of our skin exude moisture, the body is comforted and cooled by its evaporation which is effected more readily by constantly moving air. Moving air, however, does not mean a draught. In the ideally warmed house, the doors and windows are nicely placed so that the warm air gracefully exits from the top of the room and the cold air comes in from the lower parts of the room (such as lower windows or well-placed air takers.) Thus, the air is moving nicely without the least draught. So it will in the use of the fan and blower types of apparatus on the market. But before we go on to describe them, it will be well for us to review some of the reasons why humans need special air treatments. It is said by scientists that: A Woman exhales 600 cubic feet of carbon dioxide per hour. A Young Man exhales 614 A Young Woman “ 453 A Boy “ 363 A Girl “ 343