SANITATION AND VENTILATION, AS REQUIRED IN A MODERN HOUSE.

New Zealand Herald, Volume XXIX, Issue 9022, 29 October 1892, Page 1 (Supplement)

SANITATION AND VENTILATION, AS REQUIRED IN A MODERN HOUSE.

No. IV. [BY EDWARD WITHY.] Next as to the admission of pure and cool air. The restriction under which this must bo done is that no draught must be produced. The most urgent demand for air is that made by a fire. It must have a sufficient supply or it will burn dead, and emit smoke into the room; if it gets no supply it will go out as soon as it has exhausted that which was contained in the room. As every operation is conducted by nature in the easiest available way the demand of a fire for air, being made near the floor, is most easily supplied from the space under the doors or French casements. The result is that a draught is created round the feet and ankles of those who are sitting round the lire in "the hope of obtaining warmth. A very simple arrangement will prevent this. Through the floor, just inside the rim of a fender which has no bottom plate, let a number of holes be bored into the space between two joists. Nail some perforated zinc or copper over these holes to prevent sparks from entering. Break through the wall between two joists, and fix a large grating in the hole. You will then get a copious supply of fresh air to the lire from openings so placed that the current from them will not pass your feot. But there is another advantage, which is not so obvious. It is this, that a fire supplied in this way is more effective in warming the air of a room. Most of the heat derived from an ordinal*}' fireplace is radiated heat—heat which shines out into the room and thus warms the persons, the furniture, and the air which it contains. But I have shown that the air which ordinarily supplies a fire is drawn across the room from points at somo distance. It is, therefore, obvious that the air in front of the fire, which has already received some of the radiated heat, is constantly travelling towards the fire and passing up the chimney, whilst its place is being supplied by another lot of cold air from the doors, etc. This process acts continuously to curtail the zone of the fire's warming influence. Now look at the contrast presented by the improved method. Under it the lire draws its supply of air from the outside through apertures close at hand, and at the floor level. It does not draw any general current across the room. At the same time the rays of the fire penetrate and warm, as before, a quantity of air in front of itself, but which is now stationary, instead of moving towards it. This air, instead of being sent to waste up the chimney, rises as soon as it is sufficiently warm, and circulates about the room, to be replaced by cooler air from parts beyond the direct influence of the (ire. By this method, then, we have supplied the fire with air without creating a draught, and have at the same time increased its effectiveness as a dispenser of warmth. We may next proceed to cut off its old and objectionable sources of supply by fitting carpet slips on the floor close up to the underside of the doors or casements. Fig. 6 shows a section of the openings for admitting air to the fire. Having provided for the needs of the lire we have only to consider those of the gas and of the occupants. If wo open a window at the top we get a direct draught across the room or down upon the heads of those sitting. If we open one at the bottom we get a draught across the body or neck. These methods are, therefore, not admissible. We must arrango to bring air in (1) at a level at least higher than our heads when we are sitting, and ('2) in such a direction as will ensure its passing upwards and not downwards or across the room. If we can do this we shall obtain a pure air supply with the minimum of risk to health or comfort. There are two ways in which we'may do it. The simpler plan in a new house is to make the lower bar of each window sash an inch deeper, and then to build trpß»tho sill inside two inches higher than usual. This provides three inches more than the customary overlap. It will then be possible to lift the lower sash three inches without leaving a less than ordinary overlap, and, therefore, without making any opening through which a direct draught coald pass across the room. But by this lift we have separated the dividing bars of the two sashes about an inch and a-half, and in such a way that the air entering at this point must flow upwards, and cannot create a draught downwards or across the room. Fig. 7 shows the section of a window sash and sill so constructed. In an old house a rough mothod may be adopted to effect this object. Fit a piece of wood three inches deep accurately to lower side of the window sash and into the recess of the sill. When ventilation is desired lift the sash, place the piece of wood, and shut the sash down upon it. The inconveniences of this plan are that the window cannot be fastened without removing the filling piece, and that the latter has to bo stowed somewhere out of the way. The other way to admit air satisfactorily is to fit Tobin tubes against the wall and to supply them with air from the space between two joists. Where it is possible to do so a space should be selected, which extends right through the house, and each end should be provided with a grating. The reason for this through passage is that if there is only one opening into the space a wind blowing directly upon it will produce a strong rush of air up the tube, and very likely a draught in the room, whilst an opposite wind might sometimes check the proper action of gravity. The principle of the action of the Tobin tube is that of a fountain. It provides an entrance for heavy air into a reservoir of light air. The tube being placed vertically directs the air, which enters with a slight force, straight upwards until its greater weight prevails, and brings it gently downwards over the room in the form of the spray from a fountain. Ib descends so lightly as not to cause a draught in the room. Fig. 8 will explain the general arrangement of one of these tubes. It now remains to consider the measure of the various appliances for removing the warm air and supplying cool. It is not easy to lay down rules which are of general application, bub I think it may be safely stated that where ventilation fails it is more often owing to the aperture being too small than too large. All that has to be guarded against is the production of draughts and the too rapid lowering of the temperature by admitting the air too fast. This can be readily prevented by closing some of the openings. The provision must depend upon the number of persons likely to occupy a room at one time ; upon the consecutivo hours that it may be used without an opportunity being afforded for a thorough blow-through; upon the amount of gas consumed, and in some cases upon the position of the room in relation to its surroundings. Some writers give rules which may be useful to apply, bub it is beyond the scope of a short paper, and beyond the range of my experience to attempt to criticise these or to suggest others. It may, however, afford a basis for discussion if I give a few particulars of appliances which I have recently had fitted up in a new house. I will only give these for the dining-room, which will also bo largely used as a general sitting-room, by eight to 12 persons. This rooom measures 20 by 16 and is 12 feet high. It will probably be fairly illuminated with four gas burners, and will rarely have six lighted. Ib has a fireplace, two windows, one door from a passage, and two from adjoining rooms. Within the marble fender there are openings through the floor into the joist space, equal to 5-1 square inches in area, but this is reduced considerably by the perforated copper gratings. On the outer wall a 12 by 6 grating is placed over the opening into the joist space. There are two Tobin tubes measuring 10 b«32i clear inside, with a fine wire grating aPtho top, making an inlet of about 50 square inches. They communicate with a joisb space extending right through the house, with a grating on the outer wall at each end 12 by 6. The lower sashes of both windows are fitted so that they can be raised 1\ inches and then leave an overlap on the sill, to prevent direct draught, of £ of an inch. The meeting rails of the two sashes are \\ inches deep, so that the 2J inches lift separates them vertically one inch clear from each other. These two openings are each three feet long, and the clear space be-

tween the two panes of glass and the edge of each opposite meeting rail is § of an inch, giving 45 square inches for air entrance. The clear lift vertically exceeds this maximum air space by i of an inch, and is, perhaps, nob strictly necessary, but it will at least tend to reduce any throttling of the passage, and possibly to the tranquilising of the air, which enters when a wind is blowing. For the hot air exhaust the cone above the centre flower is twelve inches in diameter at the base ; a four-inch circular heavy galvanised iron pipe is soldered into the top of it, and pases upwards into the roof, there being no floor above, and connects, together with a similar pipe from another room, into a six-inch main pipe, on the top of which is fitted a six-inch Torpedo exhaust ventilator. Plato 111. shows a section and part elevation of a room fitted with the threo kinds of air inlet and the ono of exhaust which have been described. In two houses at home I found very satisfactory results from an elaborate ventilating gas-pendant), with large argand burner and globe, in performing the threefold duty of admitting fresh air, of carrying away into the chimney the products of its own combustion, and of removing the hot air from the room. These are, however, costly fittings, even at home, and I prefer admitting the fresh air into the room at a lower point than they did. In admitting air bo the tiro in the way described and to the room by Tobin ventilators I had very favourable experience for many years at homo, and can recommend both with absolute confidence as a great addition to comfort by preventing draughts and by adding to the purity of the air. In conclusion, I would venture to express tho hope that the simple effort made in this paper to familiarise householders with arrangements which are possible at moderate expense in the departments of sanitation and ventilation may rosult, as they certainly have done for a good many years in my own experience, in making some homes more healthy and enjoyable.