x.x.xVI.
WARMING AND VENTILATION
There is no department of science, as applied to practical matters, which has so often baffled experimenters as the healthful mode of warming and ventilating houses. The British nation spent over a million on the House of Parliament for this end, and failed. Our own government has spent half a million on the Capitol, with worse failure; and now it is proposed to spend a million more. The reason is, that the old open fireplace has been supplanted by less expensive modes of heating, destructive to health; and science has but just begun experiments to secure a remedy for the evil.
The open fire warms the person, the walls, the floors and the furniture by radiation, and these, together with the fire, warm the air by convection. For the air resting on the heated surfaces is warmed by convection, rises and gives place to cooler particles, causing a constant heating of its particles by movement. Thus in a room with an open fire, the person is warmed in part by radiation from the fire and the surrounding walls and furniture, and in part by the warm air surrounding the body.
In regard to the warmth of air, the thermometer is not an exact index of its temperature. For all bodies are constantly radiating their heat to cooler adjacent surfaces until all come to the same temperature.
This being so, the thermometer is radiating its heat to walls and surrounding objects, in addition to what is subtracted by the air that surrounds it, and thus the air is really several degrees warmer than the thermometer indicates. A room at 70 degrees by the thermometer is usually filled with air five or more degrees warmer than this.
Now, the cold air is denser than warm, and therefore contains more oxygen. Consequently, the cooler the air inspired, the larger the supply of oxygen and of the vitality and vigor which it imparts. Thus, the great problem for economy of health is to warm the person as much as possible by radiated heat, and supply the lungs with cool air. For when we breathe air at from 16 to 20 degrees, we take double the amount of oxygen that we do when we inhale it at 80 to 90 degrees, and consequently can do double the amount of muscle and brain work.
Warming by an open fire is nearest to the natural mode of the Creator, who heats the earth and its furniture by the great central fire of heaven, and sends cool breezes for our lungs. But open fires involve great destruction of fuel and expenditure of money, and in consequence economic methods have been introduced to the great destruction of health and life.
Of these methods, the most popular is that by which radiated heat is banished, and all warmth is gained by introducing heated air. This is the method employed in our national Capitol, where both warming and ventilation are attempted by means of _fans_ worked by steam, which force in the heated air. This is an expensive mode, used only for large establishments, and its entire failure at our capitol will probably prevent in future any very extensive use of it.
But the most common mode of warming is by heated air introduced from a furnace. The chief objection to this is the loss of all radiated heat, and the consequent necessity of breathing air which is debilitating both from its heat and also from being usually deprived of the requisite moisture provided by the Creator in all out-door air.
Another objection is the fact that it is important to health to preserve an equal circulation of the blood, and the greatest impediment to this is a mode of heating which keeps the head in warmer air than the feet.
This is especially deleterious in an age and country where active brains are constantly drawing blood from the extremities to the head.
All furnace-heated rooms have coldest air at the feet, and warmest around the head. It is also rarely the case that furnace-heated houses have proper arrangements for carrying off the vitiated air.
There are some recent scientific discoveries that relate to impure air which may properly be introduced here. It is shown by the microscope that _fermentation_ is a process which generates extremely minute plants, that gradually increase till the whole ma.s.s is pervaded by this vegetation. The microscope also has revealed the fact that, in certain diseases, these microscopic plants are generated in the blood and other fluids of the body, in a mode similar to the ordinary process of fermentation.
And, what is very curious, each of these peculiar diseases generates diverse kinds of plants. Thus in the typhoid fever, the microscope reveals in the fluids of the patient a plant that resembles in form some kinds of seaweed. In chills and fever, the microscopic plant has another form, and in small-pox still another. A work has recently been published in Europe, in which representations of these various microscopic plants generated in the fluids of the diseased persons are exhibited, enlarged several hundred times by the microscope. All diseases that exhibit these microscopic plants are cla.s.sed together, and are called _Zymotic_, from a Greek word signifying _to ferment_.
These zymotic diseases sometimes have a _local_ origin, as in the case of ague caused by miasma of swamps; and then they are named _endemic_.
In other cases, they are caused by personal contact with the diseased body or its clothing, as the itch or small-pox; or else by effluvia from the sick, as in measles. Such are called _contagious_ or _infectious_.
In other cases, diseases result from some unknown cause in the atmosphere, and affect numbers of people at the same time, as in influenza or scarlet fever, and these are called _epidemics_.
It is now regarded as probable that most of these diseases are generated by the microscopic plants which float in an impure or miasmatic atmosphere, and are taken into the blood by breathing.
Recent scientific investigations in Great Britain and other countries prove that the _power of resisting_ these diseases depends upon the purity of the air which has been _habitually_ inspired. The human body gradually accommodates itself to unhealthful circ.u.mstances, so that people can live a long time in bad air. But the "reserve power" of the body, that is, the power of resisting disease, is under such circ.u.mstances gradually destroyed, and then an epidemic easily sweeps away those thus enfeebled. The plague of London, that destroyed thousands every day, came immediately after a long period of damp, warm days, when there was no wind to carry off the miasma thus generated; while the people, by long breathing of bad air, were all prepared, from having sunk into a low vitality, to fall before the pestilence.
Mult.i.tudes of public doc.u.ments show that the fatality of epidemics is always proportioned to the degree in which impure air has previously been respired. Sickness and death are therefore regulated by the degree in which air is kept pure, especially in case of diseases in which medical treatment is most uncertain, as in cholera and malignant fevers.
Investigations made by governmental authority, and by boards of health in this country and in Great Britain, prove that zymotic diseases ordinarily result from impure air generated by vegetable or animal decay, and that in almost all cases they can be prevented by keeping the air pure. The decayed animal matter sent off from the skin and lungs in a close, unventilated bedroom is one thing that generates these zymotic diseases. The decay of animal and vegetable matter in cellars, sinks, drains, and marshy districts is another cause; and the decayed vegetable matter thrown up by plowing up of decayed vegetable matter in the rich soil in new countries is another.
In the investigations made in certain parts of Great Britain, it appeared that in districts where the air is pure the deaths average 11 in 1000 each year; while in localities most exposed to impure miasma, the mortality was 45 in every thousand. At this rate, thirty-four persons in every thousand died from poisoned air, who would have preserved health and life by well-ventilated homes in a pure atmosphere.
And, out of all who died, the proportion who owed their deaths to foul air was more than three fourths. Similar facts have been obtained by boards of health in our own country.
Mr. Leeds gives statistics showing, that in Philadelphia, by improved modes of ventilation and other sanitary methods, there was a saving of 3237 lives in two years; and a saving of three fourths of a million of dollars, which would pay the whole expense of the public schools.
Philadelphia being previously an unusually cleanly and well-ventilated city, what would be the saving of life, health, and wealth were such a city as New-York perfectly cleansed and ventilated?
Here it is proper to state again that conflicting opinions are found in many writers on ventilation, in regard to the position of ventilating registers to carry off vitiated air. Most writers state that the impure air is heavier, and falls to the bottom of a room. After consulting scientific men extensively on this point, the writer finds the true result to be as follows: Carbonic acid is heavier than common air, and, unmixed, falls to the floor. But by the principle of _diffusion of gases_, the air thrown from the lungs, though at first it sinks a little, is gradually diffused, and in a heated room, in the majority of cases, it is found more abundantly at the top than at the bottom of the room, though in certain circ.u.mstances it is more at the bottom.
For this reason, registers to carry off impure air should be placed at both the top and bottom of a room.
In arranging for pure air in dwellings, it is needful to proportion the air admitted and discharged to the number of persons. As a guide to this, we have the following calculation: On an average, every adult vitiates about half a pint of air at each inspiration, and inspires twenty times a minute. This would amount to one hogshead of air vitiated every hour by every grown person. To keep the air pure, this amount should enter and be carried out every hour for each person. If, then, ten persons a.s.semble in a dining-room, ten hogsheads of air should enter and ten be discharged each hour. By the same rule, a gathering of five hundred persons demands the entrance and discharge of five hundred hogsheads of air every hour, and a thousand persons require a thousand hogsheads of air every hour.
In calculating the size of registers and conductors, then, we must have reference to the number of persons who are to abide in a dwelling; while for rooms or halls intended for large gatherings, a far greater allowance must be made.
The most successful mode before the public, both for warming and ventilation, is that of Lewis Leeds, who was employed by government to ventilate the military hospitals and also the treasury building at Washington. This method has been adopted in various school-houses, and also by A. T. Stewart in his hotel for women in New-York City. The Leeds plan embraces the mode of heating both by radiation and convection, very much resembling the open fireplace in operation, and yet securing great economy. It is modeled strictly after the mode adopted by the Creator in warming and ventilating the earth, the home of his great earthly family. It aims to have a pa.s.sage of pure air through, every room, as the breezes pa.s.s over the hills, and to have a method of warming chiefly by radiation, as the earth is warmed by the sun. In addition to this, the air is to be provided with moisture, as it is supplied out-doors by exhalations from the earth, and its trees and plants.
The mode of accomplishing this is by placing coils of steam, or hot water pipes, under windows, which warm the parlor walls and furniture, partly by radiation, and partly by the air warmed on the heated surfaces of the coils. At the same time, by regulating registers, or by simply opening the lower part of the window, the pure air, guarded from immediate entrance into the room, is admitted directly upon the coils, so that it is partially warmed before it reaches the person: and thus cold drafts are prevented. Then the vitiated air is drawn off through registers both at the top and bottom of the room, opening into a heated exhausting flue, through which the constantly ascending current of warm air carries it off. These heated coils are often used for warming houses without any arrangement for carrying off the vitiated air, when, of course, their peculiar usefulness is gone.
The moisture may be supplied by a broad vessel placed on or close to the heated coils, giving a large surface for evaporation. When rooms are warmed chiefly by radiated heat, the air can be borne much cooler than in rooms warmed by hot-air furnaces, just as a person in the radiating sun can bear much cooler air than in the shade. A time will come when walls and floors will be contrived to radiate heat instead of absorbing it from the occupants of houses, as is generally the case at the present time, and then all can breathe pure and cool air.
We are now prepared to examine more in detail the modes of warming and ventilation employed in the dwellings planned for this work.
In doing this, it should be remembered that the aim is not to give plans of houses to suit the architectural taste or the domestic convenience of persons who intend to keep several servants, and care little whether they breathe pure or bad air, nor of persons who do not wish to educate their children to manual industry or to habits of close economy.
On the contrary, the aim is, first, to secure a house in which every room shall be perfectly ventilated both day and night, and that too without the watchful care and constant attention and intelligence needful in houses not provided with a proper and successful mode of ventilation.
The next aim is, to arrange the conveniences of domestic labor so as to save time, and also to render such work less repulsive than it is made by common methods, so that children can be trained to love house-work. And lastly, economy of expense in house-building is sought.
These things should be borne in mind in examining the plans of this work.
In the Cottage plan, (Chap II. Fig. 1,) the pure air for rooms on the ground floor is to be introduced by a wooden conductor one foot square, running under the floor from the front door to the stove-room; with cross branches to the two large rooms. The pure air pa.s.ses through this, protected outside by wire netting, and delivered inside through registers in each room, as indicated in Fig. 1.
In case open Franklin stoves are used in the large rooms, the pure air from the conductor should enter behind them, and thus be partially warmed. The vitiated air is carried off at the bottom of the room through the open stoves, and also at the top by a register opening into a conductor to the exhausting warm-air shaft, which, it will be remembered, is the square chimney, containing the iron pipe which receives the kitchen stove-pipe. The stove-room receives pure air from the conductor, and sends off impure air and the smells of cooking by a register opening directly into the exhausting shaft; while its hot air and smoke, pa.s.sing through the iron pipe, heat the air of the shaft, and produce the exhausting current. The construction of the exhausting or warm-air shaft is described on page 63.
The large chambers on the second floor (Fig. 12) have pure air conducted from the stove-room through registers that can be closed if the heat or smells of cooking are unpleasant. The air in the stove-room will always be moist from the water of the stove boiler,
The small chambers have pure air admitted from windows sunk at top half an inch; and the warm, vitiated air is conducted by a register in the ceiling which opens into a conductor to the exhausting warm-air shaft at the centre of the house, as shown in Fig. 17.
The bas.e.m.e.nt or cellar is ventilated by an opening into the exhausting air shaft, to remove impure air, and a small opening over each glazed door to admit pure air. The doors open out into a "well," or recess, excavated in the earth before the cellar, for the admission of light and air, neatly bricked up and whitewashed. The doors are to be made entirely of strong, thick gla.s.s sashes, and this will give light enough for laundry work; the tubs and ironing-table being placed close to the glazed door. The floor must be plastered with water-lime, and the walls and ceiling be whitewashed, which will add reflected light to the room.
There will thus be no need of other windows, and the house need not be raised above the ground. Several cottages have been built thus, so that the ground floors and conservatories are nearly on the same level; and all agree that they are pleasanter than when raised higher.
When a window in any room is sunk at the top, it should have a narrow shelf in front inclined to the opening, so as to keep out the rain.
In small chambers for one person, an inch opening is sufficient, and in larger rooms for two persons, a two-inch opening is needed. The openings into the exhausting air flue should vary from eight inches to twelve inches square, or more, according to the number of persons who are to sleep in the room.
The time when ventilation is most difficult is the medium weather in spring and fall, when the air, though damp, is similar in temperature outside and in. Then the warm-air flue is indispensable to proper ventilation. This is especially needed in a room used for school or church purposes.
Every room used for large numbers should have its air regulated not only as to its warmth and purity, but also as to its supply of moisture; and for this purpose will be found very convenient the instrument called the Hygrodeik, [Footnote: It is manufactured by N. M. Lowe, Boston, and sold by him: and J. Queen & Co., Philadelphia.] which shows at once the temperature and the moisture. A work by Dr. Derby on Anthracite Coal, scientific men say has done much mischief by an _unproved_ theory that the discomfort of furnace heat is caused by the pa.s.sage of carbonic _oxide_ through the iron of the furnace heaters, and _not_ by want of moisture. G.o.d made the air right, and taking out its moisture _must_ be wrong.
The preceding remarks ill.u.s.trate the advantages of the cottage plan in respect to ventilation. The economy of the mode of warming next demands attention. In the first place, it should be noted that the chimney being at the centre of the house, no heat is lost by its radiation through outside walls into open air, as is the case with all fireplaces and grates that have their backs and flues joined to an outside wall.
In this plan, all the radiated heat from the stove serves to warm the walls of adjacent rooms in cold weather; while in the warm season, the non-conducting summer casings of the stove send all the heat not used in cooking either into the exhausting warm-air shaft or into the central cast-iron pipe. In addition to this, the sliding doors of the stove-room (which should be only six feet high, meeting the part.i.tion coming from the ceiling) can be opened in cool days, and then the heat from the stove would temper the rooms each side of the kitchen. In hot weather, they could be kept closed except when the stove is used, and then opened only for a short time. The Franklin stoves in the large room would give the radiating warmth and cheerful blaze of an open fire, while radiating heat also from all their surfaces. In cold weather, the air of the larger chambers could be tempered by registers admitting warm air from the stove-room, which would always be sufficiently moistened by evaporation from the stationary boiler. The conservatories in winter, protected from frost by double sashes, would contribute agreeable moisture to the larger rooms. In case the size of a family required more rooms, another story could be ventilated and warmed by the same mode, with little additional expense.
We will next notice the economy of time, labor, and expense secured by this cottage plan. The laundry work being done in the bas.e.m.e.nt, all the cooking, dish-washing, etc., can be done in the kitchen and stove-room on the ground floor. But in case a larger kitchen is needed, the lounges can be put in the front part of the large room, and the movable screen placed so as to give a work-room adjacent to the kitchen, and the front side of the same be used for the eating-room.
Where the movable screen is used, the floor should be oiled wood. A square piece of carpet can be put in the centre of the front part of the room, to keep the feet warm when sitting around the table, and small rugs can be placed before the lounges or other sitting-places, for the same purpose.
Most cottages are so divided by entries, stairs, closets, etc., that there can be no large rooms. But in this plan, by the use of the movable screen, two fine large rooms can be secured whenever the family work is over, while the conveniences for work will very much lessen the time required.
In certain cases, where the closest economy is needful, two small families can occupy the cottage, by having a movable screen in both rooms, and using the kitchen in common, or divide it and have two smaller stoves. Each kitchen will then have a window and as much room as is given to the kitchen in great steamers that provide for several hundred.
Whoever plans a house with a view to economy must arrange rooms around a central chimney, and avoid all projecting appendages. Dormer windows are far more expensive than common ones, and are less pleasant. Every addition projecting from a main building greatly increases expense of building, and still more of warming and ventilating.
It should be introduced, as one school exercise in every female seminary, to plan houses with reference to economy of time, labor, and expense, and also with reference to good architectural taste; and the teacher should be qualified to point out faults and give the instruction needed to prevent such mistakes in practical life. Every girl should be trained to be "a wise woman" that "buildeth her house" aright.