During these smallest stages of growth, reliance for ventilation can at first be placed on crevices, occasional opening of doors, and the open chimney.
Window Bar Ventilation. When these rudimentary means become inadequate, the simple device of window bars (as I have found in my own house and office for a generation past) will keep even the air of crowded rooms freshened, without drafts. There are many patented devices embodying this principle, but there is no need to waste money on them. The village carpenter can saw out for every window a plain duplicate of the lower bar, a quarter of an inch shorter, but beveled like it, to slip in easily and tight. When the lower sash is lifted, this bar inserted, and the sash shut close to it, there is a space above between the two sashes, which at the same time lets out the foul air, and lets in the fresh, without any perceptible draft. The only caution to be observed, even in cold weather, is to put the bar on the leeward windows, away from those against which the wind is blowing too strongly. This simple fresh air system is very effective. Try it on one window anywhere, and see if you do not like it.
The Next Method. Next comes steam heat, very common, very unsatisfactory, very cheap; with radiators, very ugly in a library, very much in the way; requiring some scheme of admitting sufficient fresh air regularly, and ejecting air that has been breathed.
A low-pressure indirect hot water system gives the best heat, most easily managed and properly combined with fresh air supply. The only reason that it is not universally adopted is that steam boilers and radiators are cheaper. Here, however, is one of the alternatives in library building where the money available ought to be put into health and comfort rather than into mere show.
For ventilation, in the simpler forms of steam and hot-air heating, the simplest, cheapest, and often most effective method is to take fresh air by several inlets direct from outside, up under radiators, to be heated by passage through them and let out into the room.
In large libraries, some more effective system of heating, with forced draft ventilation by blowers, fans or inducers, must be installed by the architect under advice of competent engineers. The part of the librarian in this stage of planning will be to get the building committee to take the most effective method, rather than the cheapest, diverting to this essential of health some of the funds which can be withheld from inside or outside ornament.
Temperature. One of the striking differences between England and the United States is that in the standards of temperature, Champneys[215] calls for 60° to 62° Fahrenheit for rooms, 56° for corridors. Burgoyne[215] reports 50° in the stack at Strassburg.
The A. L. A. Committee on Ventilation and Lighting takes as the standard 70° as a medium temperature for the circular inquiries it is making. It is usually assumed that a lower standard may be set for stacks, and places where attendants or readers move around rather than sit. Certainly we try to keep our houses and offices and the reading-rooms of our libraries 68° to 70°.
In General. An article in “The Librarian,”[216] specifies five heaters, thus:—