Climate and Health in Hot Countries and the Outlines of Tropical Climatology / A Popular Treatise on Personal Hygiene in the Hotter Parts of the World, and on the Climates That Will Be Met Within Them.

by George Michael James Giles

Houses of this type are well suited to climates usually blessed with a good breeze, and in which the heat during the day does not reach such a degree as to necessitate shutting it out, and are specially adapted to places where, from scarcity of labour, there is a difficulty about the pulling of punkahs. When, however, the midday heat reaches into the nineties, such a plan of building becomes unsuitable, and it is necessary to adopt the thick-walled type of house, with comparatively few floor level openings; the object being to keep imprisoned the cooler night air, so that the interior may never approach the maximum shade temperature of the day. It is obvious that the adoption of this principle quite precludes all proper ventilation, and that unless the rooms are exceptionally large and lofty it must be positively unhealthy. At the same time, heat beyond a certain degree induces such severe nervous and physical prostration that the adoption of this course is almost unavoidable during the worst hours of the day in such climates as the Punjab; but the shorter the period the better, and as the same reasons that render the house cooler than the outer air in the day, make it hotter at night; it is always well to compensate for the lack of ventilation during the day by sleeping absolutely in the open at night.

Fig. 4.—Rough ground plan of an European Bungalow in Persia.

Too often, not only the air, but the light is shut out, a course of action which is as pernicious as it is futile, for unless the sun be shining directly into the room its temperature will be in no way raised by admitting an ample amount of light.

There can be no doubt that this baneful practice of keeping children shut up in darkened rooms is one of the principal causes of the blanched and enfeebled little ones so often met with in India; for they suffer promptly from deprivation of light, though they are wonderfully tolerant of heat, and if unchecked by their anxious mothers, will follow their own wholesome instincts, and be found romping and tumbling about with the servants and orderlies in the verandah, at temperatures that make their parents devote anxious consideration to the question of crossing a room.

Fig. 5.—Sketch of bungalow with terraced roof, of a type very common in the Punjab and United Provinces in India. Speaking generally, this bungalow is well planned. Its faults are that the verandah is too low-pitched, leaving a needlessly large proportion of the external walls exposed to the full power of the sun. The dormer or ventilating windows also are too low down, as they leave several feet of confined “dead” air at the top of the rooms. They should have been placed close up to the cornice.

The third important consideration in planning a good tropical house is that the outer walls should, as far as possible, be shielded from the direct rays of the sun by ample verandahs. Objects exposed to the full glare of the sun soon become so hot that it is difficult to handle them, reaching a temperature 40° or 50° F. higher than that of the air, and though building materials conduct heat but slowly, they do so very surely, so that the air within any building with extensive unshielded sunward walls cannot fail to be considerably hotter than that of one so planned that as small an area of wall as possible is directly exposed. Within the true Tropics, the sun must necessarily come to the northward of any localities for a longer or shorter portion of the year, and in such low latitudes it is desirable that the verandah should extend all round the house; but outside the equatorial zone the side looking away from the noon-day sun may be left unprotected as far as the coolness of the house is concerned; though a northern verandah is still desirable, as affording the most eligible position for an open air lounge during the day. Within practicable limits, a verandah can hardly be too wide, and as one of its main functions is to shield the main wall, it is also important that it should be high pitched, but this point is too often lost sight of, although the additional cost of constructing a higher-pitched verandah is very small, as the supports of these structures cost but little, in comparison with the roof. Of course the oblique rays of the sun will search into a high verandah for a longer time than they can in a low one, but this defect is easily obviated by closing the upper part of the colonade with wooden jalousies or with mats, but in this case openings should be provided in the roof to give exit to what must be almost dead air. Verandahs of less than six feet width are of comparatively little use, and 10 feet may be considered to be a fair average standard, but 15 feet is by no means excessive, if it can be afforded, and as shown in the diagram on page 9, double verandahs, consisting of two colonnades, each about 12 feet wide, are by no means uncommon in Persia.

To attain an equivalent standard of comfort, the rooms of a tropical house require to be much higher pitched than is needful in temperate climates, but it is quite possible to carry this to excess, as over a certain height, the pendulum swing of the punkah is too slow; and it is well known to students of ventilation that spaces of dead air, unsearched by the currents normally circulating through the room, are very apt to be found in too lofty apartments. From 16 to 18 feet is a good average standard, and if the height be carried many feet above the higher figure, it is desirable that a strong beam should be carried across the room, at about that level, to carry the punkah. As far as ventilation is concerned, there is probably little advantage in any height of ceiling above 13 feet, but this does not give an adequate swing for a punkah.

As already incidentally mentioned, the writer holds a strong preference for houses of two or more floors. While residents of Calcutta or Bombay will never, if they can avoid it, live on the ground floor, there is a general but quite unfounded idea, amongst up-country residents in India, that upper floors are necessarily hotter.