Hong Kong Builder
THE AIR-CONDITIONING OF CAFÉ WISEMAN
AT LANE CRAWFORD'S.
By A.L. Landsbert, M. Inst. B.E.
General view of Café Wiseman showing the ducts of the newly installed air-conditioning system
One of the most outstanding of recent engineering installations, in connection with the building industry, is the air-conditioning of Café Wiseman in the basement of Exchange Building.
This installation presented many problems to the contractors the chief of these being the limited space in which machinery could be installed, and the fact that the walls of the Café are formed by the foundations of Exchange Building, and little cutting away could be carried out to allow for air-ducts.
As the walls of Café Wiseman are almost entirely lined with marble, air-ducts on the walls, of sufficient size to carry the required quantity of conditioned air, would have been very unsightly. To overcome this difficulty, all of the main duct work was carried out through the kitchen at the rear of the Café, these being constructed of 2" Canec Insulation Board lined with Asphalt Emul- sion thereby combining the advantages of insulating the ducts from the heat of the kitchen and at the same time absorbing all air noises.
The conditioned air is brought into the Café through centralized Masonite Ducts which harmonize with the surroundings and are hardly noticeable.
The use of "Masonite" Tempered Presdwood for the construction of air ducts has great advantages, as com-
pared with the use of the conventional galvanized iron ducts, a few of which are listed below:—
(1) Their lightness in weight allows them to be fixed in position where special provision would have to be made to carry the weight of metal ducts of the same size.
(2) Masonite ducts absorb air and fan noises instead of intensifying them as is the case with the metal ducts.
(3) The insulating properties of Masonite prevents sweating on the outside of the ducts, as is the case of the metal duct when passing through air of a higher temperature than that being conveyed through the duct.
(4) The finished duct offers a perfect surface for ducoing or other finish, whereas in metal duct work it is extremely difficult to eliminate all surface defects and seams whether they be riveted or welded.
In addition to the two main ducts in the Café, two smaller ducts convey conditioned air to the service bar and to the Manager's office at the back of the kitchen. The air velocities at the different outlet grills are so designed that, although there are few outlets in compari-
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