Popular Science Monthly/Volume 41/October 1892/Warming and Ventilating of Dwellings
|WARMING AND VENTILATING OF DWELLINGS.|
THE best practical application of the principle of warm walls and cold air is undoubtedly the house which M. Somesco, civil engineer, has built for himself at Creil. We were fortunate in visiting M. Somesco on a day when a strong northeasterly gale was blowing. Wind creates greater difficulties than cold; but on this occasion we had both wind and cold. It is important to note that M. Somesco's house is built on marsh land. On both sides of the house there is a river, and but for the construction of embankments flood would constantly occur in this spot. It was necessary to dig six feet below the level of the cellar floor to find a foundation. As much masonry had to be placed under the house to form a foundation as would have sufficed to build it. The garden, in the midst of which the house stands, was also artificial. Nor is there any shelter from the winds. The house stands alone in the midst of what is now a garden, but which used to be a dismal swamp. The system of warming and of ventilation has therefore been tested under the most trying circumstances. In shape M. Somesco's house is square, measuring twelve metres. It has cellars, two floors, and above these under the roof a large sort of hall which serves as a billiard-room. The hollowed walls are fifty-five centimetres thick. The external wall is twenty-two centimetres and the inner wall eleven centimetres, so that there is an intervening space between the walls of twenty to twenty-two centimetres. These walls are made with porous bricks, but in the basement the walls are massive. The house is like one box inside another box, with a space of four to five inches between the two boxes.
Outside, at the back of the house, there is an ordinary coal-furnace. The smoke and heat from this furnace pass into a chamber built in the cellar of the house, measuring about six feet in length and not quite two feet square. From this heat-chamber and going all round the outer walls of the cellar there is an inclosed passage. Suspended in the center of this passage and also going the whole way round the house is a metallic flue of more than a foot in diameter (thirty-five centimetres internal and thirty-seven centimetres external diameter). This serves as a chimney and draws off the smoke and the heat from the furnace and heat-chamber, traveling horizontally round the four sides of the house; and then, when it is nearly back to the furnace, the flue opens into a chimney; the smoke and what heat remains go up vertically to the roof. In other words, the basement of the house is surrounded by a narrow closed passage, in the center of which is suspended the flue or chimney from the furnace, and this flue serves to warm the air in this passage. To keep the cellar cool and to retain the heat that goes round the cellar, the wall of this passage is covered over with "sluck wool" or "silicate cotton," as it is sometimes called, which is considered a better non-conductor than asbestos. All round the house communicating with this hot-air passage there are inlets of fresh air from the garden, which measure eighty by fifty centimetres and are protected by metallic gauze or webbing. If the wind is very violent, a coarse canvas may be hung in front of these air inlets on the windward side of the house. There are ten such inlets, the fresh air being delivered, as will be seen in the sectional drawing A B, below the hot-air flue. The pipe or flue rests on iron bars and on a socket that permits the easy dilatation and
Plate No. 1.
Plan of Ground-floor of M. Somesco's House at Creil, Oise, France.
The dotted lines indicate the warming flue passing down the center of the hot-air passage in the basement of the house. The plan gives the walls underneath the windows and indicates the space for hot air between the outer and inner wall. C C C, the arrows show the hot-air space between the walls. C D, the door from the garden into the. basement. B D, the back door. F D, the front door. DRD, the door from the entrance hall to the drawing-room. F, the furnace lit in the garden outside the house. The arrows from the furnace indicate how the smoke and hot air pass horizontally round the house till they reach C II, where a chimney carries the smoke vertically up to the roof. P P P P, apertures through which brushes may be passed from the garden into the smoke-flue to clean away the soot. W W W W, position of the windows.
Plate No 2.
Plan of Basement of M. Somesco's House at Creil, Oise, France.
Section A-B, showing inlet of air into the basement passage where the air is warmed. G L, the ground level of the garden. C L, the ground level of the basement or cellar. GR. F., the parlor floor, or first floor of the house. The inlet of air as indicated by the arrows is below the smoke-flue, which is suspended in the center of the passage, so as to warm the air in this passage. Section C-D. G. R. shows the outlet of the air above the smoke-flue. The air warmed by contact with this flue passes upward in the intervening space between the inner and outer walls of the house, so as to warm the entire substance of the walls.
contraction of the iron with which it is made. The drawing C D shows how the air warmed in this passage ascends into the space between the two walls of the house. There are a number of these openings into the hollow of the wall all round the house.
The temperature in the hot-air passage varies from 114° to 122° Fahr. This suffices to bring up the temperature of the inner wall on the ground-floor from 86° to 92° Fahr. The temperature of the inner wall decreases by about one degree centigrade per metre of height. Thus, if the wall on the ground-floor level is at 35°, it will be 32° C. on the level of the first floor, which is three metres higher up. The hot air that travels up the hollow of the walls comes out in the large attic under the roof of the house. If this air is warmed to from 114° to 122° Fahr. when it enters the space between the walls it will have fallen to about 104° Fahr. as it emerges from the wall into the attic. From this attic the hot air filters into the open through the porosity of the roof and by the various openings, chinks, etc.
Much of the success of this experiment depends upon the porosity of the walls. Every precaution is taken not to interfere with this porosity. There is no plaster-work put on the walls, and there is no paint or paper. A light wooden frame is nailed on to the walls, and from this tapestry—that is, a tissue, as far as possible a woolen tissue—is suspended and replaces paper. Some hangings of this description can be obtained that are hardly any dearer than good paper, and though for artistic purposes expensive woolens are employed, the expense in the long run is not great, for the cloth lasts an indefinite time, and, unlike paper, can be taken down and cleaned. It also contributes very materially to maintain the warmth of the walls. M. Somesco has now lived in this house for some years. Without the aid of fires, when the windows were shut, he has never known the temperature of the rooms fall below 54° Fahr., and this during the hardest frost. If the windows were thrown wide open the temperature indoors would not fall below 39° Fahr. in spite of the frost. The air coming through the windows is absolutely cold and frosty, but the thermometer rises under the influence of the heat radiated from the walls. There is a fireplace in each room, though fires are very rarely lighted. When, however, it is very cold weather and the windows have been open for a long time, then it is expedient to light a fire for an hour or so. As there is no loss of heat through the coldness of the walls, the room is warmed in a very short time. On the day of our visit the drawing-room windows had been open for two hours, and as the weather was very cold a fire was lighted, but soon the fire was let out, the room was too warm, the thermometer marking 78° Fahr. We left the drawingroom for some time. We opened the front door leading to the garden, and the drawing-room door, which was from four to five feet from the front door. Thus the fresh air from the garden blew freely into the drawing-room. Yet, and though there was now no fire, the radiation of heat from the walls was such that the thermometer marked 66 Fahr. In the garden the temperature was below 50° Fahr., and a strong northeasterly gale was blowing. Thus we were while indoors breathing cold, pure air from the garden.
We have seen that M. Somesco's house was built on a swamp; and yet the principal, if not the only, inconvenience from which he has suffered is extreme dryness. We visited other houses in the neighborhood and found the walls stained by the damp to a height of six or seven feet; some of M. Somesco's furniture and other objects were spoiled because the wood had split in consequence of its extreme dryness. To counteract this inconvenience, M. Somesco has been obliged to place a large number of plants in different parts of the house, a measure which, however, adds considerably to the charm and beauty of the place.
The heat and dryness thus secured cost M. Somesco ten tons of English household coals per annum. His house has fourteen rooms, and ten persons could live comfortably in it. The cost would then be one ton of coal per head per annum. But then it must be noticed that the furnace and the system of warming the passage round the basement of the house are somewhat roughly contrived, and that more economical methods of obtaining the necessary heat could be easily devised. Then it must also be noted that it is not a question of warming one room or a portion of a room, but that the entire house is equally warmed, and warmed to such an extent that doors and windows are constantlyopened, and this in spite of the exceptionally cold and damp nature of the surrounding soil and the exposed position the house occupies.
Over and above all these considerations M. Somesco maintains he has realized the ideal that a dwelling should be like our clothes, only not portable, but permeable. It should be warm, because it should be made of materials that are bad conductors of heat. Indoors we should possess means of counteracting the chilling effect of the outer air. We ought to live indoors as we live out of doors, and we should consider our house merely as if it were an extra great-coat. The coat, if porous, will be warm and healthy. One of the reasons, he says, why we are apt to feel uncomfortable when it rains is that the rain blocks up the porosity of the walls, and that, too, on the windward side. As for microbes, M. Somesco proudly pointed to the artistic drapery which covered the bare bricks of his porous walls. "These are," he exclaimed, "my microbe traps. If I have any reason to believe that injurious microbes have been introduced into my house, I know pretty well where to find them. It would take but little time or trouble to unhook all this drapery, to put it into the disinfecting stove, and there superheated steam under pressure, without injuring the cloth, would assuredly kill the microbes. Even without these artificial methods of purification, if the walls were porous, oxygen would go wherever the microbe went, and Nature would effect its own cure." How far a porous wall can filter and purify air, as earth filters and purifies sewage, is a matter which has not yet been investigated. He is of opinion that if we leave our walls alone, and do not block them up with paint and paper, we have for ordinary house walls in ordinary weather two cubic feet of air going through every square foot of wall in the course of an hour, and this is probably enough to insure the sufficient oxidation, if it goes on at all, of the materials of which the wall is made. Further, the porosity of the walls must also materially assist in the ventilation of the room which they surround. It was M. Somesco's delight to think that even when the doors and windows of his house were shut the pure air of his garden was blown upon him through the porous walls.
M. Somesco's house can, of course, only be taken as an experiment. The principles of which it is a practical application have not yet been adopted by the public. Already a private house is in the course of construction at Beauvais built on the same principles, and they are also to be applied to the military hospital at Madrid. To sum up these new theories and methods, the teachings of M. Trélat, the practical experiments of M. Somesco, suggest that the natural porosity of our walls, especially the outer walls, should not be destroyed. These walls should be decorated, not with paper and paint, but with porous, non-conducting substances, such as woolen drapery. The outer walls on the side nearest to the inner surface should be hollowed throughout, thus constituting a double wall, with a space of about four inches between the two walls. A heating contrivance of whatever description may be found most expedient or economical should be placed in the basement of the house. A warm-air chamber or shaft traveling round the base of the outer walls should supply to the hollow in the walls air taken from the outside and warmed at the point of admission into the wall to a temperature of from 100° to 120° Fahr. This should maintain the temperature of the inner wall at from 80° to 90° Fahr. Then, he considers, the walls will radiate sufficient heat through the rooms to enable the inhabitants to constantly open the doors and windows, and to breathe cold, fresh, outer air without inconvenience. As a rule, fires will be unnecessary, dampness will be completely banished from the house, and to maintain some moisture in the air it would, he thinks, be expedient to decorate the house with numerous evergreen plants. The inhabitants should then be able to benefit by unlimited ventilation, and could breathe pure, cold, and fresh air coming upon them directly from the outside.—Report of the London Lancet Sanitary Commission.