In comparing American with Australian planning, one is at once struck with the influence which the warming problem has upon the former work, an influence that often absolutely alters the scheme of arrangement and leaves but little in common between American planning and that required in a hotter climate.

The Australian practitioner is more often faced with the difficulty of cooling rather than heating his building, and away up north, in Queensland and parts of Western Australia, is often seen the strange sight of houses without chimneys at all, fires being unnecessary for warming purposes.

It may be taken, then, as an Australian problem, how to keep the building cool when the hot winds rage outside, and insect pests and dust have to be planned against.

In the scheme of ventilation, therefore, we find lofty apartments, wide verandahs, outside Venetian shutters, fly-wire doors and windows, and hollow walls, while cross passages and fanlights over internal doors are often arranged to cause through currents of air.

In spells of sudden excessively hot weather the building should be made to withstand in a degree the great outside temperature until the change comes, when it should be readily opened to allow of the free passage of cooling air.

The ventilation of public buildings is in some parts of the continent regulated by law, noticeably throughout Victoria, where the Central Board of Health has the following requirements (see Fig. 239): -

"Ventilation. - Every compartment of the buildings (including passages) must be separately ventilated. If an approved artificial system of ventilation is not adopted provision must be made. The inlets must be shafts, tubes, or hoppers opening slantingly upwards into the compartment through the external walls (either through the walls themselves or through the windows in the walls). They must as far as practicable be equally distributed along the external sides and ends of each compartment. The upper edges of their external openings must be from 3 to 5 feet 6 inches, and the lower edges of their internal openings and (where hoppers are provided) the upper edge or mouth of hopper must be from 6 feet 6 inches to 7 feet above the level of the floor of the compartment to be ventilated.

Heating And Ventilation 298

Fig. 239.

" The Outlets must be openings in the ceilings or roof lining. They must not open into the roof space, but each of them must be continued through the roof space and through the roof itself by means of a shaft or tube having a transverse area at least equal to that required for the opening (in the ceiling or roof lining) over which it is placed, and having its upper end so constructed and so protected by a cowl or shield or other appliance as to prevent the entry of rain.

" For a building consisting only of one floor (the ground floor), and for the uppermost storey of any building consisting of more than the ground floor, one-third of the area of the outlets may be provided by means of openings situated immediately below the wall-plates extending through the external walls and properly shielded outside; and from each floor but the uppermost of a building consisting of more than the ground floor, the outlets for each may be entirely provided by such means.

" All air shafts, tubes, and openings, whether for inlet or outlet of air, must be constructed so as to be readily cleaned out, and must not communicate with any cavity or space in the thickness of the wall, nor with the space intervening between the ceiling and the floor and roof covering over, and the inlets must in addition be fitted with regulating valves for opening and closing them in varying degrees.

"The clear air-way (i.e. the sectional area of the most contracted part of the ventilators, grating bars and such obstructions being therefore excluded) must be, for inlets, at least 2 square inches, and for outlets 2 square inches for every 4 square feet of floor area, except as regards existing buildings and weather-boarded buildings lined with match board lining only, in which the amount of ventilation to be provided in each case may be modified. Perforated zinc must not be fixed to either inlet or outlet vents, and wire gratings must not be less than 3/4-inch mesh.

"The clear air-way for any one inlet should not exceed 50 square inches, nor for any outlet be more than 170 square inches.

" No opening into the roof space will be allowed to supply means of communication between such space and the interior of the building.

"The space between the surface of the ground and the floor of the building must be amply ventilated."

In rural Australia the great log fires for winter evenings will always remain the classic mode of heating. In the cities the large open fireplace is more often a home idea of the owner, but little required in a new land of milder climatic conditions.

In institutions, hot-water radiation finds considerable favour for many reasons of cleanliness and economy of spacing, while electric radiators are increasingly used with the laying down of electric plants.