The Turkish Bath, Its Design and Construction

by Robert Owen Allsop

The position of air intake is a matter of great importance, especially in large towns. It evidently is bad to draw a supply of air from the bottom of an area. Even the position shown in Fig. 8 is not good: the shaft should be carried higher. The best places for the intakes are where there is always a current of pure air blowing, and away from smoky chimneys. Theoretically, it would seem that the higher the level of intake the better; but in cities, by going high we get among the belching chimney-tops, even if we escape the stagnation below. Moreover, a high inlet with a strong wind tending to exhaust the air in the shaft might find the architect with the cold air sweeping through his bath, and all the heated air rushing up the supply-shaft. A large "lobster-back" automatically turning towards the wind, would in many cases prevent such a disastrous result. Even in low-level intakes, as I have said, trouble will sometimes arise from the same cause. This may be remedied by providing more than one inlet, so that only the one facing the current of air will be employed, the other being closed, which could be effected by fixing the glass louvres, spoken of above, on pivots, and connecting them with a rod and adjustable rack. It would be a very simple matter to make the wind itself automatically open and shut the louvres.

The theory of the heating and ventilation of the hot rooms requires most careful study, and the particular scheme to be adopted in any new bath must be well considered with respect to the restrictions of the site. At Fig. 8, I have endeavoured to show how to make the best of what is perhaps a bad job: the site only admits of ventilation at a back area, it is impossible to construct flues anywhere else, and the fresh air must be drawn from the same area. On the ground floor are cooling and dressing rooms; the bath rooms are in the basement and the furnace in a sub-basement, reached from a passage at the end of the stairs for the bather. Two convoluted stoves are shown in a vault; three air-inlets are provided, and the foul air is drawn up into the smoke flues, two in number, which, above, could join one another. Let us follow the air in its passage through the bath. Entering at the intakes, any coarse impurities are thrown off by the smooth louvres, and the tendency of finer particles to rush in is checked by the stretched canvas cheese-cloths. Thus deprived of its actually visible impurities, the air passes through a longer or shorter conduit of glazed brickwork until it reaches the horizontal flues running to beneath the furnace walls, along which it is rapidly drawn, and, ascending between the walls and heating surfaces and between the two adjacent heating surfaces, absorbs the radiating heat and enters the laconicum by way of the rectangular shaft constructed above the vault spanning the two stoves.

Questions of temperature I will omit for the present. The air, on passing through the laconicum, will be practically pure, as it is in such great bulk compared with the number of occupants of this highly-heated chamber, and it will not be absolutely necessary to provide ventilators. These should commence in the calidarium, and should, in the scheme of ventilation here considered, be so disposed that the nearer they are to the lavatorium and shampooing-room, the more frequent will they become. The object of this disposition of outlets for vitiated air is, that the cross currents thus created may not interfere with the main flow from the heating chamber to the lavatorium. Were too many ventilators to be placed near the hotter end of the sudatorium, this stream would be diverted. Too much of the freshly-heated air would flow out at these points, and the onward movement of the air would be enfeebled. There would then be difficulty in maintaining the temperature in the tepidarium and lavatorium.

In passing onward through the various rooms, two changes are wrought in the air: it loses so much of the caloric with which it is charged for every foot it travels, and it becomes laden with the exhalations from the lungs of the bathers. A large proportion of carbonic acid is thrown into the air, and as the normal temperature of the human body remains, in a healthy person, at about 98° Fahr., and rises but a few points even when submitted to the action of heat, these exhalations, in addition to being heavier than air, are very much below the average temperature of a sudatory chamber. Consequently they fall, and must be extracted at the floor level.

The total area of the outlets for vitiated air should be about equal to the area of the narrowest part of the shaft that conducts the fresh, hot air from the heating chamber. Thus, supposing the latter to be 5 superficial feet, and the size of outlet ventilators a clear 12 in. by 3 in., there may be 20 ventilators disposed round the bath-rooms, say 4 in the calidarium, 7 in the tepidarium, and 9 in the combined shampooing room and lavatorium.

In the diagrams at Figs. 8 and 9 the foul-air conduit is the space comprised under the marble-topped benches running round the hot rooms. At the end of the laconicum they enter flues, which I have shown as running side by side with the smoke flues.

Other methods of heating the air, besides those mentioned, include coils of iron flue-pipes in a brick chamber—a principle that has been frequently adopted in the past—and plain cylindrical iron radiating stoves, such as employed at the Hammam in Jermyn Street.

Fig. 9.
Section of Hot Room, showing Foul-air Conduit.

In the latter plan, however, a great expense is created by the large number of furnace-fires to be kept constantly burning. An exposed stove in a hot room, has, moreover, the objection to its use that it re-heats the air in the bath, which should never on any account be done.